Report 2013–5206

Home , Arc Dome, Monitor Range, Mount Jefferson (Nevada)

Geochronology and Correlation of Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Scientific Investigations Report 2013–5206

U.S. Department of the Interior U.S. Geological Survey

Geochronology and Correlation of Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

By Daniel R. Shawe, Lawrence W. Snee, Frank M. Byers, Jr., and Edward A. du Bray

Scientific Investigations Report 2013–5206

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2014

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Suggested citation: Shawe, D.R., Snee, L.W., Byers, F.M., Jr., and du Bray, E.A., 2014, Geochronology and correlation of Tertiary volcanic and intrusive rocks in part of the southern Toquima Range, Nye County, Nevada: U.S. Geological Survey Scientific Investigations Report 2013–5206, 105 p., 1 plate, http://dx.doi.org/10.3133/sir20135206.

ISSN 2328-0328 (online) iii

Contents

Abstract...... 1 Introduction...... 1 General Geology of the Southern Toquima Range...... 3 Summary of Tertiary Igneous Activity...... 3 Tertiary Intrusive and Volcanic Rocks: Synthesis of Previous Findings...... 4 Rhyolite and Andesite Dikes and Granodiorite Stock East of Round Mountain...... 4 Rocks of a Caldera Mostly Buried Beneath Alluvium of Big Smoky Valley...... 4 Megabreccia of Jefferson Canyon (Unit Tjc)...... 4 Northumberland Tuff and Volcanic Megabreccia of Northumberland Caldera...... 5 Ash-Flow Tuffs of Poorly Defined Corcoran Canyon Caldera (Unit Tcc)...... 5 Layered Pumice Tuff, Ash-Flow Tuff, and Volcanic Megabreccia Related to Big Ten Peak Caldera...... 5 Ash-Flow Tuff of Ryecroft Canyon (Unit Trc) and Related Rocks of an Inferred Caldera Mostly Buried Beneath Alluvium of Monitor Valley...... 5 Volcanic Units between Big Ten Peak Caldera and Inferred Ryecroft Canyon Caldera...... 6 Moores Creek Caldera...... 6 Tuff of Mount Jefferson and Eruptive and Intrusive Rocks of the Mount Jefferson Caldera (Unit Tmj)...... 6 Megabreccia of Jefferson Summit (Unit Tjs)...... 8 Tuff of Round Mountain (Unit Ttr)...... 8 Volcaniclastic Rocks of Little Table Mountain (Unit Tlt) and Megabreccia of Bull Frame Canyon (Unit Tbf)...... 9 Isom-Type Ash-Flow Tuff (Unit Ti)...... 9 Shingle Pass Tuff (Unit Tsp)...... 9 Eruptive and Intrusive Rocks of the Manhattan Caldera and Associated Volcanic Units...... 9 Bates Mountain Tuff (Unit TbtD), Tuff of Clipper Gap (Unit Tcg), and Tuff of Pipe Organ Spring (unit Tpo)...... 11 Vitrophyric Ash-Fall Tuff (Unit Tva)...... 11 40Ar/39Ar Geochronology of Volcanic Units...... 11 Phenocryst Compositions as Determined by Electron Microprobe...... 22 Analytical Methods, Mineral Structural Formula Calculations, and Samples Analyzed...... 22 Results of Phenocryst Analyses...... 22 Megabreccia of Jefferson Canyon (Unit Tjc)...... 22 Tuff of Corcoran Canyon (Unit Tcc)...... 23 Tuff of Ryecroft Canyon (Unit Trc)...... 25 Tuff of Mount Jefferson (Unit Tmj)...... 26 Isom-Type Ash-Flow Tuff (Unit Ti)...... 29 Bates Mountain Tuff (Part of Unit Ty)...... 30 Petrogenesis of the Tuff of Mount Jefferson (Unit Tmj), and Its Possible Relation to Other Tuffs...... 32 Interpretative Summary of Phenocryst Compositions...... 33 The Southern Toquima Range Caldera Complex, a Summary...... 34 Acknowledgments...... 34 References...... 34 iv

Appendix 1. 40Ar/39Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada (p. 39)...... Link Appendix 2. Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 61)...... Link Appendix 3. Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 69)...... Link Appendix 4 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 77)...... Link Appendix 5. Compositions (in Weight Percent) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 85)...... Link Appendix 6. Structural Formulas (in Atoms) and Amphibole Species of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 89)...... Link Appendix 7. Compositions (in Weight Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 93)...... Link Appendix 8. Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada (p. 97)...... Link

Plate

1. Geologic Map of the Southern Toquima Range, Nye County, Nevada, Showing Tertiary Volcanic and Intrusive Rock Units Studied, Locations of 40Ar/39Ar Dating Samples, and Locations of Samples That Contain Chemically Analyzed Phenocrysts...... Link

Figures

1. Map of the southern Toquima Range, Nevada, showing calderas discussed in this report...... 2 2. Diagrams of 40Ar/39Ar age spectra of minerals in volcanic rocks of the southern Toquima Range, Nye County, Nevada...... 13 3. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of one sample, southern Toquima Range, Nye County, Nevada...... 23 4. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of one sample, southern Toquima Range, Nye County, Nevada...... 23 5. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of one sample, southern Toquima Range, Nye County, Nevada...... 24 6. Ternary diagram showing proportions of wollastonite, enstatite, and ferrosilite in clinopyroxene of one sample, southern Toquima Range, Nye County, Nevada...... 24 7. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of two samples, southern Toquima Range, Nye County, Nevada...... 24 8. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of three samples, southern Toquima Range, Nye County, Nevada...... 25 9. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of three samples, southern Toquima Range, Nye County, Nevada...... 25 10. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of three samples, southern Toquima Range, Nye County, Nevada...... 26 v

11. Ternary diagram showing molecular end-member proportions of albite, anorthite, and orthoclase feldspars in two samples, southern Toquima Range, Nye County, Nevada...... 26 12. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of three samples, southern Toquima Range, Nevada...... 27 13. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of three samples, southern Toquima Range, Nye County, Nevada...... 27 14. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing relative cation abundances in biotite of two samples, southern Toquima Range, Nye County, Nevada...... 27 15. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of seven samples, southern Toquima Range, Nye County, Nevada...... 28 16. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of three samples, southern Toquima Range, Nye County, Nevada...... 28 17. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of one sample, southern Toquima Range, Nevada...... 28 18. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of seven samples, southern Toquima Range, Nye County, Nevada...... 29 19. Ternary diagram showing proportions of wollastonite, enstatite, and ferrosilite clinopyroxene in six samples, southern Toquima Range, Nye County, Nevada...... 30 20. Ternary diagram showing molecular end-member proportions of albite, anorthite, and orthoclase feldspars in two samples, southern Toquima Range, Nye County, Nevada...... 30 21. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of two samples southern Toquima Range, Nye County, Nevada...... 30 22. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of two samples, southern Toquima Range, Nye County, Nevada...... 31 23. Ternary diagram showing proportions of wollastonite, enstatite, and ferrosilite in pyroxenes in three samples, southern Toquima Range, Nye County, Nevada...... 31 24. Ternary diagram showing molecular end-member proportions of albite, anorthite, and orthoclase feldspars in two samples, southern Toquima Range, Nye County, Nevada...... 31 25. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of two samples, southern Toquima Range, Nye County, Nevada...... 32 26. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of two samples, southern Toquima Range, Nye County, Nevada...... 33 27. Ternary diagram showing molecular end-member proportions of albite, anorthite, and orthoclase in feldspars in two samples, southern Toquima Range, Nye County, Nevada...... 33

Table

1. Summary of 40Ar/39Ar dates for Toquima Range, Nevada, mineral separates...... 12

Abbreviations Used in This Report km kilometer m meter Ma million years ago PI phenocryst index

Geochronology and Correlation of Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

By Daniel R. Shawe, Lawrence W. Snee, Frank M. Byers, Jr., and Edward A. du Bray

Abstract Extensive 40Ar/39Ar dating of about 60 samples that represent many of the Tertiary extrusive and intrusive rocks in Extensive volcanic and intrusive igneous activity, the southern Toquima Range provides precise ages that refine the chronology of previously dated units. New geochronologic partly localized along regional structural zones, characterized data indicate that the petrogenetically related Corcoran the southern Toquima Range, Nevada, in the late Eocene, Canyon, Ryecroft Canyon, and Mount Jefferson calderas Oligocene, and Miocene. The general chronology of igneous formed during a period of about 560,000 years. activity has been defined previously. This major episode of Electron microprobe analyses of phenocrysts Tertiary magmatism began with emplacement of a variety of from 20 samples of six dated units underscore inferred intrusive rocks, followed by formation of nine major calderas petrogenetic relations among some of these units. In particular, and associated with voluminous extrusive and additional compositions of augite, hornblende, and biotite in tuffs erupted intrusive activity. Emplacement of volcanic eruptive and from the Corcoran Canyon, Ryecroft Canyon, and Mount collapse megabreccias accompanied formation of some Jefferson calderas are similar, which suggests that magmas calderas. Penecontemporaneous volcanism in central Nevada represented by these tuffs have similar petrogenetic histories. resulted in deposition of distally derived outflow facies ash- The unique occurrence of hypersthene in Isom-type tuff flow tuff units that are interleaved in the Toquima Range with confirms its derivation from a source beyond the southern proximally derived ash-flow tuffs. Toquima Range. Eruption of the Northumberland Tuff in the north part of the southern Toquima Range and collapse of the Northumberland caldera occurred about 32.3 million years ago. The poorly defined Corcoran Canyon caldera farther to the southeast Introduction formed following eruption of the tuff of Corcoran Canyon about Rocks in the southern Toquima Range in south-central 27.2 million years ago. The Big Ten Peak caldera in the south Nevada define a major episode of Tertiary magmatism that part of the southern Toquima Range Tertiary volcanic complex culminated in late Oligocene time with formation of several formed about 27 million years ago during eruption of the tuff of calderas and associated major ash-flow tuff eruptions (fig. 1). Big Ten Peak and associated air-fall tuffs. The inferred Ryecroft Caldera formation was preceded by emplacement of a variety Canyon caldera formed in the south end of the Monitor Valley of intrusive rocks and involved additional intrusive and adjacent to the southern Toquima Range and just north of the Big voluminous extrusive activity. Formation of volcanic eruptive Ten Peak caldera in response to eruption of the tuff of Ryecroft and collapse megabreccias accompanied the evolution of some Canyon about 27 million years ago, and the Moores Creek calderas. Penecontemporaneous volcanism elsewhere in the caldera just south of the Northumberland caldera developed at region also resulted in deposition of outflow facies ash-flow about the same time. Eruption of the tuff of Mount Jefferson tuff units in the Toquima Range. about 26.8 million years ago was accompanied by collapse of Our interest is focused on a block of six 1:24,000-scale the Mount Jefferson caldera in the central part of the southern quadrangles (fig. 1) mapped between 1967 and 1993, mostly Toquima Range. An inferred caldera, mostly buried beneath by the senior author (see Shawe, 1995, 1998, 1999a, b, 2001, alluvium of Big Smoky Valley southwest of the Mount Jefferson 2003a; Shawe and Byers, 1999; Shawe, Hardyman, and caldera, formed about 26.5 million years ago with eruption of Byers, 2000). A recompiled 1:48,000-scale geologic map of the tuff of Round Mountain. The Manhattan caldera south of the six quadrangles provides a synoptic view of the Tertiary the Mount Jefferson caldera and northwest of the Big Ten Peak igneous rocks (Shawe, 2002) in this area. The purpose of the caldera formed in association with eruption of a series of tuffs, present report is to clarify chronology and correlations of the principally the Round Rock Formation, mostly ash-flow tuff, numerous volcanic and intrusive units exposed in the area and about 24.4 million years ago. to interpret the petrogenesis of a few of the volcanic units. 2 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

117°00' 116°45'

NEVADA 39°00'

Northumberland MAP LOCATION

R A N G E

V a l l e y

Moores Creek DRS-91-74

S m o k y Mount Jefferson M o n i t o r V a l l e y

117°07'30" 117°00' 116°52'30" 116°45' 38°45' 38°45' Dry G IN JEFFERSON R Canyon CANYON FAULT P S R Round E I FAULT Corcoran D Mountain L Canyon ROUND O CORCORAN S RH-TP-672 MOUNTAIN CANYON MEADOW

Big GQ–1756 CANYON I–2680 FAULT JEFFERSON I–2670 38°37'30" T O Q U I M A

Manhattan Ryecroft Canyon MANHATTAN BELMONT BELMONT MANHATTANGQ–1775 WEST EAST FAULT GQ–1801 I–2675

H U N T S

38°30' 38°30' R A Index to 7.5-minute N C H

quadrangles

F AU LT

Big Ten Peak

R a l s t o n V a l l e y BIG TEN PEAK FAULT M O N I T O R R A N G E

38°15' Base from U.S. Geological Survey data, 1956, Tonopah, Nev., 1:250,000 0 3 6 MILES Universal Transverse Mercator projection, Zone 11 North American Datum of 1927 (NAD 27) 0 3 6 KILOMETERS Figure 1. Southern Toquima Range, Nevada, showing calderas discussed in this report, area of plate 1, and locations of samples discussed in report that fall outside plate 1. Tan shading, calderas. Summary of Tertiary Igneous Activity 3

Geologic mapping in the area by Shawe and associates (Shawe, 1988, 2003b; Shawe, Marvin, and others, 1986; produced a general framework for the Tertiary igneous Shawe, Naeser, and others, 1987; and Shawe, Kucks, and activity of the southern Toquima Range. A generalized Hildenbrand, 2004). geologic map of this area (plate 1) portrays the distribution Several studies in parts of the southern Toquima of the intrusive and volcanic units that are the subject of this Range beyond the area considered herein are pertinent to study. Several earlier studies, including K-Ar age dating understanding the Tertiary igneous activity within our study (Silberman and others, 1975) of many of the intrusive and area and are frequently referenced in the following text. volcanic units, resulted in a chronology of events that define basic volcanic stratigraphic relations and helped define several calderas. Petrographic studies (modal analyses) Summary of Tertiary Igneous Activity (Shawe, 1995; 1998; 1999a, b; Shawe and Byers, 1999; Shawe, Hardyman, and Byers, 2000) were also important Tertiary magmatism began about 36–35 million years in defining volcanic unit correlations. Microprobe analyses ago (Ma) (Shawe, Marvin, and others, 1986) when a swarm of volcanic rock phenocrysts, reported here, also facilitate of rhyolite dikes, a granodiorite stock (granodiorite of Dry stratigraphic correlations. Recent 40Ar/39Ar geochronology Canyon; Shawe, 1995) and, a few kilometers east of Round investigations presented here further refine stratigraphic Mountain, several andesite dikes were intruded into one relations and confirm correlation of several units, either with of the Cretaceous granite plutons. About 33 Ma, a caldera units elsewhere in the southern Toquima Range or with units (now mostly covered by alluvium in Big Smoky Valley just derived from distant sources. Studies of the Tertiary igneous west of the Toquima Range) formed during ash-flow tuff rocks in the area by others (as referenced in later sections) eruption (Henry, 1997). About the same time, eruption of the have provided critical additional information used to establish Northumberland Tuff from a source about 25 kilometers (km) the Tertiary igneous history of the area. to the north formed the Northumberland caldera (McKee, Data presented in this report are used to refine earlier 1974). As summarized by Henry (1997), volcanic activity interpretations concerning the identity and ages of some units culminated in the southern Toquima Range between about and to confirm the identity of some units derived from sources 27.2 and 24.4 Ma, with formation of successive calderas that beyond the southern Toquima Range. All volcanic rock erupted the tuff of Corcoran Canyon (Boden, 1986) from the composition names are in accord with the International Union poorly defined Corcoran Canyon caldera (Shawe, Hardyman, of Geological Sciences’ chemical classification nomenclature and Byers, 2000; Shawe, Kucks, and Hildenbrand, 2004), (Le Bas and others, 1986). the tuff of Big Ten Peak (Keith, 1993) from the Big Ten Peak caldera southeast of our map area, the tuff of Ryecroft Canyon (Boden, 1986) from a proposed caldera mostly covered by General Geology of the Southern alluvium in Monitor Valley (Shawe and Byers, 1999), the tuff of Moores Creek (McKee, 1974) from the Moores Creek Toquima Range caldera north of our map area, the tuff of Mount Jefferson (Boden, 1986) from the Mount Jefferson caldera, the tuff of The oldest rocks exposed in the southern Toquima Round Mountain (Boden, 1986; Shawe, 1995; Henry, 1997) Range are of Paleozoic age, chiefly marine sedimentary rocks. from a caldera mostly covered by alluvium in Big Smoky Cambrian and Ordovician rocks deposited in the ocean west Valley, and the Round Rock Formation (Shawe, 1999a) from and outboard of the North American craton were thrust into the Manhattan caldera. Several intrusive bodies, commonly the study area during several episodes of tectonism that began localized near or along caldera margins, were emplaced in the late Paleozoic and continued until the Late Cretaceous. during the same period. The ash-flow tuffs erupted from During tectonism, individual thrust plates were strongly folded these calderas are calc-alkalic trachydacites to rhyolites. and internally deformed. In the Late Cretaceous, as thrust Eruptive megabreccias, localized along structural margins, faulting waned, three granite plutons were emplaced into the are a notable feature of several of the southern Toquima Paleozoic rocks. Intrusion was accompanied by metamorphism Range calderas (Shawe and Snyder, 1988). Several eruptive of adjacent Paleozoic rocks; subsequently the plutons were megabreccia deposits are associated with the Manhattan domed by additional intrusive activity, metamorphosed, and and Mount Jefferson calderas and are probably derived mineralized locally. from other calderas in the area. Diagnostic characteristics Igneous activity during the Tertiary included formation of the megabreccia deposits include their occurrence as of several calderas, eruption of large volumes of ash-flow tuff, outflow facies deposits, large clasts of rock types not present and emplacement of associated intrusive bodies and volcanic at the surface, basal zones of welded ash (vitrophyre), megabreccia throughout large parts of the southern Toquima and occasional clasts encased in volcanic glass, which are Range (fig. 1). Mineralizing episodes, some commercially indicative of derivation from deeper, hotter levels within the important, are related to igneous events described elsewhere source magma reservoir. 4 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Tertiary Intrusive and Volcanic Rocks: None of the rhyolite, granodiorite, or andesite intrusions has been dated by the 40Ar/39Ar method. Given that sanidine Synthesis of Previous Findings usually provides more accurate K-Ar ages than biotite and that the method is more accurate than fission track ages, Stratigraphic positions summarized in this section of radiometric data suggest that the biotite K-Ar and the fission- previously described volcanic and intrusive rocks and those track ages presented in the previous discussion are slightly too documented in the present study are shown in the correlation old. However, because sanidine is known to not completely of map units on plate 1. melt and release all of its contained 40Ar in conventional K-Ar dating, anomalously young ages may result. Rhyolite and Andesite Dikes and Granodiorite Stock East of Round Mountain Rocks of a Caldera Mostly Buried Beneath Alluvium of Big Smoky Valley Radiometric dates of rhyolite dikes (Tr) from a swarm that intrudes Cretaceous granite and its wall rocks east Henry (1997) described a 32.18 [32.37]±0.13 Ma of Round Mountain include a K-Ar date on sanidine of (40Ar/39Ar on sanidine) tuff; the bracketed age is explained 34.3±0.9 Ma (Marvin and others, 1973) and K-Ar dates on later in this paragraph. This tuff erupted from a caldera, which impure sanidine of 34.4±1.2, sanidine of 34.7±1.2 Ma, biotite he named the Dry Canyon caldera (fig. 1) that is mostly buried of 36.0±1.2 Ma, and biotite of 35.1±1.2 Ma (Shawe, Marvin, beneath alluvium of Big Smoky Valley near Round Mountain. and others, 1986). A fission-track date on zircon from a min- (See discussion in following paragraph.) All ages reported for eralized rhyolite dike is 36.3±1.7 Ma (Shawe, Marvin, and samples from the Toquima Range by Henry (1997) assumed others, 1986). a standard age of 27.84 Ma for Fish Canyon Tuff sanidine. • 34.3±0.9 Ma (K-Ar on sanidine; Marvin and Consequently, these ages (and others cited herein that were others, 1973) also calculated assuming an age of 27.84 Ma for Fish Canyon Tuff sanidine) must be increased by 0.19 Ma to facilitate direct • 34.4±1.2 Ma (K-Ar on impure sanidine; Shawe, comparison with new data described herein. Ages recalculated Marvin, and others, 1986) in this fashion are enclosed in square brackets [ ] herein. • 34.7±1.2 Ma (K-Ar on sanidine; Shawe, Marvin, • 32.18 [32.37]±0.13 Ma (40Ar/39Ar on sanidine; and others, 1986) Henry, 1997) • 35.1±1.2 Ma (K-Ar on biotite; Shawe, Marvin, and others, 1986) Megabreccia of Jefferson Canyon (Unit Tjc) • 36.0±1.2 Ma (K-Ar on biotite; Shawe, Marvin, A megabreccia unit exposed in Jefferson Canyon (Tjc) and others, 1986) at the southwest margin of the Mount Jefferson caldera was • 36.3±1.7 Ma (fission-track on zircon; Shawe, inferred by Shawe and Snyder (1988) and Shawe (1995, Marvin, and others, 1986) 1999b) to be a product of a 27-Ma caldera-forming eruption. The granodiorite stock of Dry Canyon (Tgd) (Shawe, However, the unit, designated as megabreccia of Dry Canyon 1981, 1995) intruded the rhyolite dike swarm and granite east by Boden (1986) and megabreccia of Jefferson Canyon of Round Mountain. Two fission-track dates on zircon from by Shawe (1995), has a biotite K-Ar date of 32.3±0.7 Ma the granodiorite are 36.1±1.6 Ma and 37.4±2.3 Ma. A fission- (Boden, 1986). Henry (1997) related the unit to ash-flow track date on sphene from the same rock is 36.2±2.0 Ma tuff erupted from a caldera (Dry Canyon caldera) buried (Shawe and others, 1986). beneath alluvium of Big Smoky Valley (see previous discussion). The tuff unit yielded a sanidine 40Ar/39Ar date of • 36.1±1.6 Ma (fission-track on zircon; Shawe and 32.18 [32.37]±0.13 Ma (Henry, 1997) and a sanidine 40Ar/39Ar others, 1986) date of 32.56 [32.75]±0.07 Ma on vitrophyric material • 36.2±2.0 Ma (fission-track on sphene; Shawe and (DRS-92-1) from the megabreccia unit (Shawe, 1995). Shawe others, 1986). (1995, 1999b) suggested that contamination of the matrix of • 37.4±2.3 Ma (fission-track on zircon; Shawe and the megabreccia unit by assimilated granitic material may others, 1986) have compromised the determined ages of the unit, or that the dated material in the unit consists of 32-Ma clasts contained in Ta Andesite dikes ( ) intrude the granodiorite stock a younger megabreccia matrix related to the Mount Jefferson and rhyolite dikes. A K-Ar date on biotite from a latite dike caldera. Phenocryst composition data for sample DRS-91-92 of the andesite set is 36.5±1.2 Ma (Shawe, Marvin, and cited later in this report suggest that the megabreccia and the others, 1986). tuff of Mount Jefferson (Tmj) are unrelated, and the presence • 36.5±1.2 Ma (K-Ar on biotite; Shawe, Marvin, of a 32-Ma caldera buried beneath Big Smoky Valley alluvium and others, 1986) seems plausible. Tertiary Intrusive and Volcanic Rocks: Synthesis of Previous Findings 5

• 32.18 [32.37]±0.13 Ma (40Ar/39Ar on sanidine; Layered Pumice Tuff, Ash-Flow Tuff, and Henry, 1997) Volcanic Megabreccia Related to Big Ten • 32.3±0.7 Ma (K-Ar on biotite; Boden, 1986). Peak Caldera • 32.56 [32.75]±0.07 Ma (40Ar/39Ar on vitrophyric sanidine; Shawe, 1999) On the basis of an association between caldera rocks and dated rocks in the southeast corner of the map area (Shawe, Naeser, and others, 1987), Keith (1993) inferred a minimum Northumberland Tuff and Volcanic Megabreccia age of about 27 Ma for formation of the Big Ten Peak caldera of Northumberland Caldera (fig. 1) southeast of our study area. Volcanic and intrusive units in that area (Shawe and Byers, 1999) include andesite According to McKee (1974), collapse of the plugs and flows (Tap); Shawe, Naeser, and others (1987) Northumberland caldera (fig. 1) and eruption of the compos- reported biotite K-Ar dates of 26.3±0.9 Ma to 26.8±1.0 Ma ite ash-flow Northumberland Tuff occurred about 32.3±1 Ma for unit Tap and a K-Ar date of 27.0±1.0 Ma for biotite in a (K-Ar on sanidine). The caldera is about 32 km in diameter, white ash-fall tuff unit (Tat). A tuffaceous claystone-siltstone- Tcs about half of which is buried beneath alluvium of Big Smoky sandstone unit ( ) that underlies, and in part interfingers with, the white ash-fall tuff (Tat), a layered pumice tuff (Tpt), Valley to the west. Prior to major caldera collapse, a rela- and a biotite-quartz latite ash-flow tuff (Tbql) that underlies tively thin ash-flow sheet was emplaced as far as about 25 km the white ash-fall tuff unit, the claystone-siltstone-sandstone beyond the present caldera margin. Enormous “landslide” unit, and the layered pumice tuff, all appear to be continuous blocks and chaotic breccia of Paleozoic rocks are preserved with the tuff of Big Ten Peak to the south (Keith, 1987). along the northeast and south caldera margins. These materi- Volcanic megabreccia within and near the Big Ten caldera als, locally enclosed in an ash matrix, may consist of caldera was interpreted by Keith (1993) to be of eruptive origin. collapse deposits or represent eruptive megabreccia. The A northwest-southeast-striking fault marks the southwest Northumberland Tuff consists of two or more ash-flow cooling margin of the caldera, which locally also includes a zone units, interlayered in places with thin water-laid sediments. of megabreccia. The tuff is a crystal-rich calc-alkalic rhyolite; quartz and sanidine are the principal phenocrysts; biotite and plagioclase • 26.3±0.9 to 26.8±1.0 Ma (K-Ar on biotite; Shawe, phenocrysts are rare but ubiquitous (McKee, 1974). Naeser, and others, 1987) • 32.3±1 Ma (K-Ar on sanidine; McKee, 1974) • 27.0±1.0 Ma (K-Ar on biotite; Shawe, Naeser, and others, 1987) Ash-Flow Tuffs of Poorly Defined Corcoran Ash-Flow Tuff of Ryecroft Canyon (Unit Trc) Canyon Caldera (Unit Tcc) and Related Rocks of an Inferred Caldera Mostly Evidence cited by Shawe, Hardyman, and Byers (2000) Buried Beneath Alluvium of Monitor Valley and Shawe, Kucks, and Hildenbrand (2004) indicates the presence of a poorly defined Corcoran Canyon caldera (fig. 1) Shawe and Byers (1999) proposed that the ash-flow from which the trachydacite tuff of Corcoran Canyon (Tcc) tuff of Ryecroft Canyon (Trc) (Boden, 1986) was erupted (Boden, 1986) was erupted. Boden (1986, 1992) reported from a caldera (fig. 1) mostly buried beneath alluvium a sanidine K-Ar date of 27.7±0.7 Ma and McKee and John in the south part of Monitor Valley. Thick sections of the Ryecroft Canyon, believed to be intracaldera fill, border the (1987) reported a biotite K-Ar date of 27.1±0.7 Ma, both south part of Monitor Valley. Shawe and Byers (1999) and for samples from the upper part of the unit. Sanidine from Shawe, Hardyman, and Byers (2000) described two types another sample (DRS-91-82) of this unit yielded a 40Ar/39Ar of rhyolite in the Ryecroft Canyon: typical (22–35 percent date of 27.36±0.06 Ma. Locally, slabs of a lower member of phenocrysts are quartz), and quartz-rich (35–45 percent overlie an upper member of the tuff of Corcoran Canyon of phenocrysts are quartz). Shawe and Byers (1999) (Tcc). Shawe, Hardyman, and Byers (2000) suggested that discerned no consistent spatial or stratigraphic distribution the juxtaposition resulted from collapse near the margin of of the two rhyolite types. Boden (1986, 1992) reported a the Mount Jefferson caldera. Alternatively, an earlier collapse sanidine K-Ar date of 25.0±0.5 Ma for what he defined may have occurred along an inferred margin of the Corcoran as the upper quartz-rich part of the tuff of Ryecroft Canyon, Canyon caldera. whereas we report 40Ar/39Ar dates of 27.05±0.06 Ma • 27.1±0.7 Ma (K-Ar on biotite; McKee and John, 1987) (DRS-91-31) and 26.82±0.04 Ma (DRS-85-224) on sanidine and a sanidine 40Ar/39Ar isochron date (DRS-85-225) 40 39 • 27.36±0.06 Ma ( Ar/ Ar on sanidine, this report) of 27.13±0.03 Ma for samples from the (undivided) • 27.7±0.7 Ma (K-Ar on sanidine; Boden, 1986, 1992) Ryecroft Canyon. (Sample locations are shown on pl. 1 6 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada unless otherwise noted.) Henry (1997) reported a sanidine Tuff of Mount Jefferson and Eruptive and 40 39 Ar/ Ar date of 27.08 [27.27]±0.09 Ma for the tuff of Intrusive Rocks of the Mount Jefferson Ryecroft Canyon. Caldera (Unit Tmj) • 25.0±0.5 Ma (K-Ar on sanidine; Boden, 1986, 1992) • 26.82±0.04 Ma (40Ar/39Ar on sanidine; this report) The rocks of the Mount Jefferson caldera (fig. 1) were initially described in some detail by Boden (1986, 1992). He • 27.05±0.06 Ma (40Ar/39Ar on sanidine; this report) defined three members of the tuff of Mount Jefferson (Tmj), 40 39 • 27.13±0.03 Ma ( Ar/ Ar on sanidine; this report) including a lower member (not within area of plate 1) that is • 27.08 [27.27]±0.09 Ma (40Ar/39Ar on sanidine; exposed only north of the area of our mapped quadrangles, Henry, 1997) an upper member, and a capping member. He also designated A cluster of undated rhyolite flow domes Tfd( ) at the an outflow member, the tuff of Round Mountain Ttr( ), which south end of Monitor Valley (Shawe and Byers, 1999) form is now thought to have been erupted from a caldera largely an arc coincident with the inferred south margin of the caldera buried beneath alluvium of Big Smoky Valley (discussed in from which the tuff of Ryecroft Canyon seemingly was the next section). Boden (1986, 1992) reported sanidine K-Ar erupted. These domes may represent a late magmatic event dates of 26.5±0.5 Ma and 25.9±0.5 Ma, and a biotite K-Ar associated with evolution of the inferred caldera. date of 26.6±0.6 Ma for his upper member. He reported a The megabreccia of Meadow Canyon (Tmc) and the sanidine K-Ar date of 25.8±0.5 Ma for his capping member. tuff of Antone Canyon (Tac) are related to the tuff of Ryecroft We describe Boden’s upper member as the principal member Canyon (Trc) inasmuch as they interfinger with, and are of this formation (because his lower member is absent in our petrologically similar to, the tuff of Ryecroft Canyon. They map area) and Boden’s capping member (lowest unit thereof) were emplaced probably late during development of the as an upper member (Shawe, 1999b). Henry (1997) considered caldera from which the Ryecroft Canyon was erupted (Shawe, Boden’s (1986, 1992) lower member of the tuff of Mount 1999b). The megabreccia of Hunts Canyon (Tmh) (Shawe Jefferson to be associated with the Moores Creek caldera and Byers, 1999), southwest of the inferred structural margin (Boden, 1986). of the Ryecroft Canyon caldera, contains mostly clasts of the • 25.8±0.5 Ma (K-Ar on sanidine; Boden, 1986, 1992) Ryecroft Canyon and likely represents outflow facies tuff erupted in the late stages of caldera development. • 25.9±0.5 Ma (K-Ar on sanidine; Boden, 1986, 1992) • 26.5±0.5 Ma (K-Ar on sanidine; Boden, 1986, 1992) Volcanic Units between Big Ten Peak Caldera • 26.6±0.6 Ma (K-Ar on biotite; Boden, 1986, 1992). and Inferred Ryecroft Canyon Caldera The principal member of the tuff of Mount Jefferson (Tmj) (Shawe, 1999b) is the volumetrically dominant part As suggested by their position between and marginal of the formation exposed in the map area. As previously to both calderas, several volcanic units, including rhyolite described (Shawe, 1995, 1998, 1999a, b; Shawe and Byers, Tfd flows and domes ( ) (see previous discussion), a rhyolitic 1999; Shawe, Hardyman, and Byers, 2000), the unit consists lahar (Tlh) (flow breccia), a vitrophyric rhyolitic lava Trv( ), chiefly of quartz latitic to rhyodacitic welded ash-flow tuff. megabreccia of Hunts Canyon (Tmh) (discussed previously), The geochemistry of these rocks indicates that they are and a mesobreccia unit (Tms) (Shawe, 1998; Shawe and composed of rhyolite (SiO 69.6–74.2 percent). Analyzed Byers, 1999), could be cogenetic. These units have not been 2 vitrophyric units are trachydacite to dacite to rhyolite- radiometrically dated. dacite in composition (SiO2 67.1 percent, 68.2 percent, and 69.3 percent). Modal analyses of these rocks have allowed Moores Creek Caldera their classification using the phenocryst index (PI; the sum of quartz and alkali feldspar contents divided by the sum of A thick accumulation of apparently intracaldera high- plagioclase and mafic minerals, including biotite, hornblende, silica rhyolite ash-flow tuff (27.3±0.5 Ma on sanidine, pyroxene, and opaque minerals) of Shawe (1999b) and Shawe, 27.0±0.8 Ma on biotite) is peripheral to the north margin of the Hardyman, and Byers (2000). Five categories based on modal Mount Jefferson caldera (Boden, 1986) and is locally adjacent PI data for rocks of the tuff of Mount Jefferson are as follows: to volcanic megabreccia. Boden (1986) reported a K-Ar date of 26.1±1.1 Ma for sanidine from a rhyolite plug that intruded 1. Category 1 PI=0.81–1.00 the north margin of the Moores Creek caldera (fig. 1). 2. Category 2 PI=0.61–0.80 • 26.1±1.1 Ma (K-Ar on sanidine; Boden, 1986) 3. Category 3 PI=0.41–0.60 • 27.0±0.8 Ma (K-Ar on biotite; Boden, 1986) 4. Category 4 PI=0.21–0.40 • 27.3±0.5 Ma (K-Ar on sanidine; Boden, 1986) 5. Category 5 PI=0.00–0.20 Tertiary Intrusive and Volcanic Rocks: Synthesis of Previous Findings 7

The composition of phenocryst assemblages ranges from more • 26.83±0.05 Ma (40Ar/39Ar on sanidine; this report) evolved (PI 1) to less evolved (PI 5), although the chemistry • 26.83±0.07 Ma (40Ar/39Ar on sanidine; this report) of these rocks is uniformly moderately evolved. • 26.85±0.04 Ma (40Ar/39Ar on sanidine; this report) Boden (1986, 1992) considered the southeast part 40 39 of what we have included in the Mount Jefferson caldera • 26.87±0.04 Ma ( Ar/ Ar on sanidine; this report) (and the associated principal member of the tuff of Mount • 26.91±0.07 Ma (40Ar/39Ar on sanidine; this report) Jefferson) to form a separate, younger eruptive center • 27.00±0.06 Ma (40Ar/39Ar on sanidine; this report) designated as the Trail Canyon caldera. He apparently defined • 27.07±0.05 Ma (40Ar/39Ar on sanidine; this report) the caldera on the basis of the determined age of the tuff of Trail Canyon, namely sanidine K-Ar dates of 23.9±0.5 Ma • 26.86±0.05 Ma (40Ar/39Ar on biotite; this report) and 23.5±0.4 Ma (Boden’s lower member) and 23.5±0.4 Ma • 26.93±0.07 Ma (40Ar/39Ar on biotite; this report) (Boden’s upper member). We believe Boden’s tuff of Trail 40 39 Canyon to be equivalent to tuff of Mount Jefferson, on • 26.99±0.06 Ma ( Ar/ Ar on biotite; this report) the basis of field mapping in the 1980s and petrographic • 27.02±0.07 Ma (40Ar/39Ar on biotite; this report) studies by R.F. Hardyman, then of the U.S. Geological • 27.06±0.06 Ma (40Ar/39Ar on biotite; this report) Survey (written commun., 1985). To test that hypothesis, • 27.08±0.04 Ma (40Ar/39Ar on biotite; this report) we determined numerous radiometric ages. • 27.10±0.04 Ma (40Ar/39Ar on biotite; this report) • 23.5±0.4 Ma (K-Ar on sanidine; lower member; Boden, 1986, 1992) • 26.69±0.04 Ma (40Ar/39Ar on hornblende; this report) • 23.5±0.4 Ma (K-Ar on sanidine; upper member; • 26.78±0.14 Ma (40Ar/39Ar on hornblende; this report) Boden, 1986, 1992) • 27.07±0.05 Ma (40Ar/39Ar on hornblende; this report) • 23.9±0.5 Ma (K-Ar on sanidine; Boden, 1986, 1992) The age of ash-flow tuffs in the two areas are statistically Samples collected west of the area of Boden’s Trail indistinguishable, which substantiates their correlation. Canyon caldera (west of the Soldier Spring fault—that is, the Petrographic data (Shawe, 1999b; Shawe, Hardyman, and area mapped as tuff of Mount Jefferson, fig. 1), yielded sanidine Byers, 2000) and phenocryst composition data reported in 40Ar/39Ar dates of 26.78±0.05 Ma (sample DRS-85-10), a later section of this report also support correlation of 26.78±0.06 Ma (DRS-85-78), and 26.86±0.04 Ma (DRS-85-48), these tuffs. and biotite 40Ar/39Ar dates of 26.79±0.04 Ma (sample Several intrusive bodies were emplaced along the structural margin of the Mount Jefferson caldera or in DRS-85-10), 26.85±0.05 Ma (DRS-85-78), 26.89±0.05 Ma northwest-striking structural zones near the caldera during, (DRS-85-48). or closely following, its collapse and fill by ash-flow tuff, • 26.78±0.05 Ma (40Ar/39Ar on sanidine; this report) volcanic-eruptive megabreccia, and possibly volcanic-collapse • 26.78±0.06 Ma (40Ar/39Ar on sanidine; this report) megabreccias. A rhyolite plug (Trp) intrudes the megabreccia of Meadow Canyon (Tmc) along the Meadow Canyon fault 40 39 • 26.86±0.04 Ma ( Ar/ Ar on sanidine; this report) (fig. 1), a northwest-striking structure just south of the south • 26.79±0.04 Ma (40Ar/39Ar on biotite; this report) structural margin of the caldera. The Meadow Canyon fault is southeast of, and is en echelon to, the northwest-striking • 26.85±0.05 Ma (40Ar/39Ar on biotite; this report) Jefferson Canyon fault (fig. 1), which marks the southwest • 26.89±0.05 Ma (40Ar/39Ar on (biotite; this report) margin of the Mount Jefferson caldera. Reported ages for the Samples collected within the area of Boden’s Trail plug include a sanidine K-Ar date of 26.4±0.3 Ma (Boden, 1986, 1992), a biotite K-Ar date of 26.4±0.8 (McKee and John, Canyon caldera (east of the Soldier Spring fault) yielded 1987) and a sanidine 40Ar/39Ar date of 26.96 [27.15]±0.06 sanidine 40Ar/39Ar dates of 27.07±0.05 Ma (sample (Henry, 1997). DRS-91-98), 26.83±0.05 Ma (DRS-91-171), 27.00±0.06 Ma (RH-TP-571), 26.87±0.04 Ma (RH-TP-583), 26.85±0.04 Ma • 26.4±0.3 Ma (K-Ar on sanidine; Boden, 1986, 1992) (RH-TP-590), 26.83±0.07 Ma (RH-TP-644), and • 26.4±0.8 (K-Ar on biotite; McKee and John, 1987) 26.91±0.07 Ma (RH-TP-646); biotite dates of 27.06±0.06 Ma • 26.96 [27.15]±0.06 (40Ar/39Ar on sanidine; Henry, 1997) (sample DRS-91-98), 27.10±0.04 Ma (DRS-91-171), About 1 km southeast of this plug and also intruded 27.02±0.07 Ma (RH-TP-571), 26.86±0.05 Ma (RH-TP-583), along the Meadow Canyon fault, two small plugs intruded 26.99±0.06 Ma (RH-TP-590), 27.08±0.04 Ma (RH-TP-644), the megabreccia of Meadow Canyon. These plugs are and 26.93±0.07 Ma (RH-TP-646); and hornblende ages surrounded by a zone of heterolithic breccia (Thb) interpreted of 27.07±0.05 Ma (sample DRS-91-171), 26.69±0.04 Ma to have resulted from forceful intrusion of the plugs into the (RH-TP-583), and 26.78±0.14 Ma (RH-TP-644). megabreccia (Shawe, 1999b; Shawe, Hardyman, and Byers, 8 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

2000). Henry (1997) reported a sanidine 40Ar/39Ar date of megabreccia likely is transitional from the underlying tuff. The 27.14 [27.33]±0.06 Ma for one of these plugs. A plug (Tooth locally altered megabreccia is younger than at least part of the Rock) that intruded the tuff of Mount Jefferson in the east 26.8–26.7 Ma tuff of Mount Jefferson, and it probably is older part of the Mount Jefferson caldera, about 1 km inside the than an alteration event that affected a nearby exposure of tuff caldera structural margin, was dated by Boden (1986, 1992) of Mount Jefferson. Biotite from this tuff produced a K-Ar as 21.7±0.4 Ma on sanidine, by McKee and John (1987) as date of 25.7±0.6 Ma (Shawe, 1999b); the date of the altered 26.2±0.8 Ma by K-Ar on biotite, and by Henry (1997) as exposure is thought to reflect the date of alteration. 26.65 [26.84]±0.06 Ma by 40Ar/39Ar on biotite. • 25.7±0.6 Ma (K-Ar on biotite; Shawe, 1999b) • 26.2±0.8 Ma (K-Ar on biotite; McKee and John, 1987) 40Ar/39Ar dates for samples of three clasts (DRS-85-122, • 26.65 [26.84]±0.06 Ma (40Ar/39Ar on biotite; DRS-85-128, DRS-85-176; appendix 1) from the megabreccia Henry, 1997) of Jefferson Summit dike (Tjs on map plate this report; unit • 21.7±0.4 Ma (K-Ar on sanidine; Boden, 1986, 1992) Tjsi of Shawe (1999b)), provide information about some dike • 27.14 [27.33]±0.06 Ma (40Ar/39Ar on sanidine; components. A date on a white-mica–mineralized clast of Henry, 1997) quartzite of Cambrian Gold Hill Formation (80.2±0.14 Ma; A small hydrothermally altered and slightly mineralized sample DRS-85-122) suggests that quartzite underlying or plug (Trp) that appears to intrude the tuff of Mount Jefferson enclosed in the Round Mountain granite pluton was affected (Tmj) (sample DRS-91-58A) but is surrounded by Quaternary by postgranite emplacement metamorphism and mineralization alluvium (Qs) and Miocene(?) megabreccia (Tcm) (Shawe, (Shawe, 1995, 2003b) and became entrained in the Jefferson Hardyman, and Byers, 2000), about 0.5 km inside the east Summit megabreccia (Tjs) when the megabreccia was erupted. structural margin of the Mount Jefferson caldera, was dated A clast of porphyritic granite (DRS-85-128) gave a date of by 40Ar/39Ar on potassium feldspar as 26.73±0.05 Ma. approximately 80 Ma and a clast of andesite (DRS-85-176) 40 39 • (26.73±0.05 Ma; 40Ar/39Ar on potassium feldspar; gave a Ar/ Ar date of 33.35±0.06 Ma. The andesite clast Shawe, Hardyman, and Byers, 2000) indicates the presence of a blind intrusion at depth because the nearest surface exposure of andesite is at least 6 km distant. Several small plugs close to or along the structural margin of the Mount Jefferson caldera north of our study • 80.2±0.14 Ma (40Ar/39Ar on white mica; Shawe (1999b) 40 39 area were dated by Henry (1997) by Ar/ Ar on sanidine • 80 Ma (approximately); (40Ar/39Ar on porphyritic granite; as 26.60 [26.79]±0.07 Ma, 26.54 [26.73]±0.08 Ma, Shawe (1999b) 26.60 [26.79]±0.08 Ma, 26.93 [27.12]±0.09 Ma, 26.93 [27.12]±0.06 Ma, and 26.57 [26.76]±0.05 Ma. • 33.35±0.06 Ma (40Ar/39Ar on andesite; Shawe (1999b) • 26.54 [26.73]±0.08 Ma (40Ar/39Ar on sanidine; Henry, 1997) Tuff of Round Mountain (Unit Ttr) • 26.57 [26.76]±0.05 Ma (40Ar/39Ar on sanidine; Henry, 1997) Henry (1997) defined a caldera mostly covered by alluvium in Big Smoky Valley as the source of the tuff of • 26.60 [26.79]±0.07 Ma (40Ar/39Ar on sanidine; Round Mountain (Ttr), and he dated intracaldera tuff of the Henry, 1997) caldera as 26.51 [26.70]±0.03 Ma (40Ar/39Ar on sanidine). 40 39 • 26.60 [26.79]±0.08 Ma ( Ar/ Ar on sanidine; Boden (1986, 1992) previously reported dates for the Henry, 1997) tuff of Round Mountain (described by him as the Round • 26.93 [27.12]±0.06 Ma (40Ar/39Ar on sanidine; Mountain member of the tuff of Mount Jefferson, which Henry, 1997) he considered to be outflow facies tuff) as 26.5±0.4 Ma, • 26.93 [27.12]±0.09 Ma (40Ar/39Ar on sanidine; 26.8±0.8 Ma, 27.3±1.1 Ma, and 26.8±0.5 Ma (all K-Ar on Henry, 1997) sanidine), and 27.2±0.6 Ma, 25.5±0.6 Ma, and 24.4±0.6 Ma (all K-Ar on biotite). Shawe and others (1987) reported a sanidine K-Ar date of 27.0±1.0 Ma, a biotite K-Ar date of Megabreccia of Jefferson Summit (Unit Tjs) 26.7±1.7 Ma, a zircon fission-track date of 26.0±2.6 Ma, and an apatite fission-track date of 28.4±7.8 Ma for the tuff of The megabreccia of Jefferson Summit (Tjs) (Shawe, Round Mountain. 1999b) consists mostly of granitic material that fills three inferred pipes and a dike (the inferred emplacement conduits) • 24.4±0.6 Ma (K-Ar on biotite; Boden, 1986, 1992) and an inferred outflow sheet (with tuff matrix locally near • 25.5±0.6 Ma (K-Ar on biotite; Boden, 1986, 1992) base) lying conformably on the ash-flow tuff of Mount Jefferson (Tmj). Abundant cobble-size clasts of granite • 26.7±1.7 Ma (K-Ar on biotite; Shawe and others, 1987) in the uppermost tuff of Mount Jefferson indicate that the • 27.2±0.6 Ma (K-Ar on biotite; Boden, 1986, 1992) Tertiary Intrusive and Volcanic Rocks: Synthesis of Previous Findings 9

• 26.5±0.4 Ma (K-Ar on sanidine; Boden, 1986, 1992) Shingle Pass Tuff (Unit Tsp) • 26.51 [26.70]±0.03 Ma (40Ar/39Ar on sanidine; Henry, 1997) The Shingle Pass Tuff (Tsp) in the southern Toquima • 26.8±0.5 Ma (40Ar/39Ar on sanidine; Boden, 1986, 1992) Range consists of an upper and a lower member. The formation appears to be conformable upon Isom-type ash- 40 39 • 26.8±0.8 Ma ( Ar/ Ar on sanidine; Boden, 1986, 1992) flow tuff (Ti) and conformable beneath unit D of the Bates • 27.0±1.0 Ma (K-Ar on sanidine; Shawe and Mountain Tuff (included in unit Ty, map plate this report). others, 1987) The upper member, however, is disconformable above the • 27.3±1.1 Ma (40Ar/39Ar on sanidine; Boden, 1986, 1992) lower member. According to Best and others (1989) the upper member has a sanidine 40Ar/39Ar date of 26.00±0.03 • 26.0±2.6 Ma (zircon fission-track; Shawe and [26.19±0.03] Ma and the lower member has a sanidine others, 1987) 40Ar/39Ar date of 26.68±0.03 [26.87±0.03] Ma. The apparent • 28.4±7.8 Ma (apatite fission-track; Shawe and notable interval between the ages of the two units may indicate others, 1987) that the lower member was considerably eroded before deposition of the upper member (separated locally by unit D of the Bates Mountain Tuff), as is true in the north-central part Volcaniclastic Rocks of Little Table Mountain of our study area (Shawe, 1999b). (Unit Tlt) and Megabreccia of Bull Frame • 26.00±0.03 [26.19±0.03] Ma (40Ar/39Ar on sanidine, Canyon (Unit Tbf) upper member; Best and others, 1989) The tuff of Mount Jefferson (Tmj) is overlain by a sequence • 26.68±0.03 [26.87±0.03] Ma (40Ar/39Ar on sanidine, of interlayered volcaniclastic rocks including tuffaceous clastic lower member; Best and others, 1989) units, ash-flow tuff, and zeolitic tuff. Tuffaceous sandstone Tlt( ) (sample DRS-92-16) near the base of the volcaniclastic rocks is 26.65±0.07 Ma (40Ar/39Ar on sanidine). The volcaniclastic rocks Eruptive and Intrusive Rocks of the Manhattan are petrographically similar to, and therefore probably related Caldera and Associated Volcanic Units to, the tuff of Mount Jefferson; they may represent products of Mount Jefferson caldera deposited during its waning stages. Early studies that referred to Tertiary igneous rocks • 26.65±0.07 Ma (40Ar/39Ar on sanidine; this report) in the southern Toquima Range (Ferguson, 1921, 1924; The megabreccia of Bull Frame Canyon (Tbf) occupies Ferguson and Cathcart, 1954) attempted correlation of these a small area above volcaniclastic rocks of Little Table Mountain rocks with units identified outside the area. Ferguson (1924) (Tlt). The megabreccia is lithologically similar to that of the originally assigned some of the silicic ash-flow tuffs in the tuff of Ryecroft Canyon (Trc) and is probably a local deposit Manhattan mining district to the Esmeralda Formation, of reworked megabreccia of Meadow Canyon (Tmc). a late Miocene to late Pliocene unit of somewhat similar lithology in the Tonopah district, 70 km south of the town Isom-Type Ash-Flow Tuff (Unit Ti) of Manhattan, Nev. Ferguson considered the silicic ash- flow tuffs to be rhyolite lava flows, although he recognized Locally, an ash-flow tuff unit Ti( ) petrographically akin breccias, tuffs, and sandstones within the volcanic section. to the 27-Ma Isom Formation in eastern Nevada and western However, radiometric age studies by Shawe and others Utah (Best and others, 1989) apparently conformably overlies (1986) showed that the rocks in the southern Toquima Range the volcaniclastic rocks of Little Table Mountain (Tlt). According are of latest Oligocene age (25.0±0.8 Ma, K-Ar on biotite). to Best and others (1989), the Isom to the east is about 27 Ma; (Epochs as related to dates rely upon U.S. Geological Survey sanidine from a sample (RH-TP-616) of the tuff (Ti) collected Geologic Names Committee, 2010.) The Round Rock Member 40 39 in the northeast part of our study area gave a Ar/ Ar date of of Ferguson’s Esmeralda Formation was raised in rank to 27.22±0.07 Ma. However, this date may not be accurate owing Round Rock Formation (Trr) and the name Esmeralda is 40 to excess Ar; the Isom-type unit clearly lies above the tuff of not used in the southern Toquima Range (Shawe, 1987). Tmj Mount Jefferson ( ) (27.07–26.69 Ma) and the overlying Subsequently, Henry (1997) provided a 40Ar/39Ar date Tlt volcaniclastic rocks of Little Table Mountain ( ) (26.65 Ma). of 24.44 [24.63]±0.11 Ma on sanidine from an ash-flow • 26.65 Ma (volcaniclastic rocks of Little Table tuff of the Round Rock Formation in the south part of the Mountain; this report) Manhattan caldera. • 27 Ma (Isom Formation ash-fall tuff; Best and • 24.44 [24.63]±0.11 Ma (40Ar/39Ar on sanidine; others, 1989) Henry, 1997) • 27.07–26.69 Ma (tuff of Mount Jefferson; this report) • 25.0±0.8 Ma (K-Ar on biotite; Shawe and others, • 27.22±0.07 Ma (40Ar/39Ar on sanidine; this report) 1986) 10 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Ferguson (1924) recognized a breccia unit in his Round Mountain Lake Beds Member of the Esmeralda Formation. Rock Member, but he considered it to be a talus unit; he Shawe (1987) revised the unit as the Bald Mountain named it the Hedwig Breccia Member (name now abandoned) Formation (Tbm). These materials probably were deposited of the Esmeralda Formation. This unit was redefined as in a shallow basin formed by minor collapse of the Manhattan the megabreccia of Sloppy Gulch (Tsg), an eruptive ash- caldera following the latest eruptions that produced the upper flow megabreccia in the lower member of the Round Rock member of the Round Rock Formation and deposition of the Formation (Trr) (Shawe, 1987; Shawe and Snyder, 1988). Diamond King Formation. Rhyolite blocks in a middle megabreccia unit of the An ash-flow tuff was designated as the quartz latite Round Rock Formation (Shawe, 1987) were described member of the Esmeralda Formation by Ferguson (1924), who by Ferguson (1924) as the Maris Rhyolite (name now considered these materials to be composed of lava flows; the abandoned). Ferguson and Cathcart (1954) subsequently tuff was deposited above the Bald Mountain Formation (Tbm). correlated the Maris Rhyolite with the Oddie Rhyolite of Radiometric age studies (K-Ar on biotite) provided dates of the Tonopah area, also a Miocene formation. No radiometric 24.8±0.8 Ma and 24.6±0.8 Ma for the unit (Shawe and others, age determinations have been made on rocks of the middle 1986). Shawe (1987) tentatively correlated the unit with the megabreccia unit of the Round Rock Formation. An inferred rhyolite-andesite volcanic neck was mapped within the tuff of Peavine Creek (Brem and Snyder, 1983) in the Toiyabe Manhattan caldera near its southwest margin; the feature is Range about 20 km west of Manhattan, Nev., on the basis of interpreted as the source of the middle megabreccia member similar petrography and age. Subsequently, Shawe (1999a) of the Round Rock Formation (Shawe, 1999a). renamed this tuff where it is exposed within the Manhattan The Diamond King Member (Ferguson, 1924) of the caldera as the tuff of The Bald Sister (his unit Tbs). Esmeralda Formation (Diamond King raised to formation • 24.6±0.8 Ma (K-Ar on biotite; Shawe and others, 1986) rank by Shawe, 1987) overlies the Round Rock Formation • 24.8±0.8 Ma (K-Ar on biotite; Shawe and others, 1986) (Trr) in the Manhattan caldera. The Diamond King Member was considered to be about 25 Ma (Shawe, 1999a) because Two principal intrusive units were emplaced within the Shawe, Marvin, and others (1986) reported biotite K-Ar Manhattan caldera. An andesite that Ferguson and Cathcart dates of 24.6±0.8 Ma and 24.8±0.8 Ma for the tuff of The (1954) designated Gilbert Andesite was correlated with a unit Bald Sister (Tbs), which overlies the Diamond King. In a of that name in the Gilbert mining district 65 km southwest more recent study (published earlier than the Shawe (1999a) of Manhattan and was assigned to the Pliocene. According to report), the ash-flow tuff of the Diamond King Formation Silberman and McKee (1972), the Gilbert in its type area is (Tdk) from the east part of the Manhattan caldera was dated Miocene (15.1±0.6 Ma, K-Ar on sanidine(?)). An uncertain by 40Ar/39Ar on sanidine as 24.34 [24.53]±0.07 Ma (Henry, K-Ar date on plagioclase from what was Ferguson’s (1924) 1997). Shawe (1998) speculated, on the basis of similar age Gilbert Andesite in the Manhattan caldera, now named Crone and petrography, that the Diamond King correlates with Gulch Andesite (Tca) by Shawe (1987), is 22.6±1.4 Ma the tuff of Arc Dome exposed in the Toiyabe Range about (earliest Miocene, but the range of uncertainty straddles the 35 km northeast of Manhattan (Brem and others, 1991; Oligocene-Miocene boundary of 23.03 Ma; Shawe and others, John, 1992), and was erupted from the Arc Dome caldera in 1986). However, Shawe and Snyder (1988) inferred the unit to the Toiyabe Range. Henry (1997), however, described the be latest Oligocene on the basis of geologic relations with dated Diamond King as part of the tuffs that fill the Manhattan units. A second intrusive unit was identified by Ferguson (1924) caldera, even though composition of the Diamond King is as dacite; Ferguson and Cathcart (1954) considered the unit to considerably different from the composition of the underlying be an outlier of the Toiyabe Quartz Latite (name abandoned Round Rock Formation within the caldera. Shawe and Byers by John, 1992) exposed in the Toiyabe Range 30 km west (1999) described a crystal-rich tuff having a composition of Manhattan. However, the Toiyabe in its type area consists and age similar to those of the Diamond King; this tuff, mostly of ash-flow tuffs and cannot be correlated with the which is exposed in the south part of the map area east of dacite intrusions in the Manhattan caldera. These rocks were Ralston Valley and described as a crystal-rich, ash-flow tuff designated dacite of Ferguson Hill (Tf) by Shawe (1987). Two unit, Tos, also is likely equivalent to the Diamond King radiometric age determinations have been made on a satellitic Formation (Tdk). dike near the plugs of this unit; one K-Ar date on biotite is • 24.34 [24.53]±0.07 Ma (40Ar/39Ar on sanidine; 25.5±0.9 Ma and another on biotite is 23.5±0.8 Ma (Shawe Henry, 1997) and others, 1986). • 24.6±0.8 Ma (K-Ar on biotite; Shawe and others, 1986) • 15.1±0.6 Ma (K-Ar on sanidine(?); Silberman and • 24.8±0.8 Ma (K-Ar on biotite; Shawe and others, 1986) McKee, 1972) Immediately overlying the Diamond King Formation is • 22.6±1.4 Ma (K-Ar on plagioclase; Ferguson, 1924) a sequence of tuffaceous lakebed sediments and minor fluvial sandstone and conglomerate layers composed mostly of • 23.5±0.8 Ma (K-Ar on biotite; Shawe and others, 1986) volcanic clasts. Ferguson (1924) designated the unit as Bald • 25.5±0.9 Ma (K-Ar on biotite; Shawe and others, 1986) 40Ar/39Ar Geochronology of Volcanic Units 11

Several small rhyolite to rhyodacite plugs (Trd) were • 22.1±0.3 Ma (tuff of Clipper Gap; Boden, 1992) intruded into megabreccia along the east and northeast • 23.6±0.4 Ma (K-Ar on sanidine; Boden, 1986, 1992) structural margins of the Manhattan caldera (Shawe, 1988). • 25.49±0.05 Ma (40Ar/39Ar on sanidine; this report) One of these plugs was dated (Shawe, 1988) as 24.8±0.9 Ma (K-Ar on biotite). The Manhattan caldera also includes • 25.61±0.05 Ma (40Ar/39Ar on sanidine; this report) four associated eruptive megabreccia units (Shawe and Snyder, 1988). Vitrophyric Ash-Fall Tuff (Unit Tva) • 24.8±0.9 Ma (K-Ar on biotite; Shawe and Snyder, 1988) A vitrophyric (glass-shard) ash-fall tuff (Tva) dated as 12.6±2.6 Ma (fission-track on zircon, Shawe, Naeser, and Bates Mountain Tuff (Unit TbtD), Tuff of Clipper others, 1987) forms a small outcrop at the northwest edge of Ralston Valley (unit Tva, rhyolite volcanic ash, of Shawe, Gap (Unit Tcg), and Tuff of Pipe Organ Spring 1998). The vitrophyric tuff is from an unknown source (unit Tpo) (Shawe and others, 1987), possibly southeast of the southern Toquima Range. Two ash-flow tuff units, unit D of the Bates Mountain • 12.6±2.6 Ma (fission-track on zircon; Shawe, Naeser, Tuff (unit TbtD of Shawe and Byers, 1999, and tuff of and others, 1987) Clipper Gap, unit Tcg of Shawe, 1999b), from different sources outside but near our mapped area, are similar to the 40 39 tuff of Pipe Organ Spring (unit Tpo of Shawe, 1999b). Unit D Ar/ Ar Geochronology (upper Oligocene–lower Miocene, on the basis of correlation of Volcanic Units with rocks in various localities outside our mapped area) consists mostly of crystal-poor rhyolitic ash-flow tuff and Sixty mineral separates extracted from 28 rock samples from minor tuffaceous sediments, aggregating less than about the Toquima Range, Nevada, were dated by the 40Ar/39Ar age- 60 meters (m) in thickness. The tuff of Clipper Gap and the spectrum technique in the U.S. Geological Survey Denver Argon Bates Mountain Tuff have limited distributions in the map area Laboratory. The new argon dates were determined by assuming a (they are included in younger ash-flow tuffs, unit Ty, pl. 1). standard age of 28.03 Ma for Fish Canyon Tuff sanidine. Earlier The tuff of Pipe Organ Spring (late Oligocene–early Miocene), reported ages for samples from the Toquima Range (Shawe, named for a locality in the northeast part of our study area Hardyman, and Byers, 2000) analyzed in the Denver Argon (Shawe, 1999b; Shawe, Hardyman, and Byers, 2000), is a Laboratory assumed a standard age of 27.84 Ma for Fish Canyon crystal-poor rhyolitic ash-flow tuff mostly less than about Tuff sanidine. Consequently, the earlier-determined ages must be 90 m thick. The tuff of Pipe Organ Spring consists locally increased by 0.19 Ma to facilitate direct comparison with new data of two members, an upper member (unit Tpu of Shawe, described herein. Ages recalculated in this fashion are enclosed Hardyman, and Byers, 2000), and a lower member (unit Tpl in square brackets [ ] herein. The dated samples are primarily of of Shawe, 1999b), which appears to be equivalent, on the Tertiary age; two Cretaceous-age clasts recovered from Tertiary basis of petrographic similarity, to member 2 (unit Trt2) of breccias also were dated. Geochronology results are summarized in table 1 and raw data are presented in appendix 1. Standard Boden’s tuffs and sedimentary rocks of Road Canyon (Boden, procedures, summarized in the footnote of appendix 1 and by Snee 1986, 1992), about 12 km north of our map area. The upper (2002), were used to determine ages of the analyzed samples. New member of the tuff of Pipe Organ Spring (unit Tpu of 40Ar/39Ar dates for numerous Toquima Range Tertiary volcanic Shawe, Hardyman, and Byers, 2000), is separated locally rocks range from 33.35±0.06 Ma to 24.92±0.05 Ma. from the lower member (unit Tpl of Shawe, 1999b), by A sample of the tuff of Clipper Gap (Ty) (RH-TP-659) unit D of the Bates Mountain Tuff, mentioned earlier. A 40 39 yielded biotite, hornblende, and sanidine separates. The biotite sanidine Ar/ Ar date (sample DRS-85-27) for the lower age spectrum (fig. A2 ) defines a plateau that includes more than member is 25.49±0.05 Ma. Unit D of the Bates Mountain 72.9 percent of the released 39Ar, with an age of 24.88±0.05 Ma. Tuff is similar to a unit in the lower member of Boden’s The hornblende spectrum (fig. B2 ) is slightly disturbed and tuffs of Road Canyon, for which he determined a sanidine saddle-shaped, and it indicates excess 40Ar; 42.2 percent of K-Ar date of 23.6±0.4 Ma (Boden, 1986, 1992). However, a the released 39Ar indicates a date of 24.85±0.18 Ma. The sample (DRS-91-74) (fig. 1) collected from a tuff unit in the sanidine spectrum (fig. C2 ) indicates excess 40Ar, but more lower part of Boden’s Road Canyon section (Boden, 1986, than 24.7 percent of the released 39Ar suggests a date of 1992), and underlying a tuff unit similar to unit D of the 24.99±0.11 Ma. All of these apparent ages overlap within error, Bates Mountain Tuff, gave a sanidine age of 25.61±0.05 Ma. but because the biotite age spectrum is undisturbed, it provides The tuff of Clipper Gap (late Oligocene), which is similar our best estimate of the age of the tuff. to an upper member of the tuffs of Road Canyon near our • 24.85±0.18 Ma (40Ar/39Ar on hornblende; this report) study area and dated by Boden (1992) as 22.1±0.3 Ma, is 40 39 a crystal-poor rhyolitic ash-flow tuff, generally less than • 24.88±0.05 Ma ( Ar/ Ar on biotite; this report) 45 m thick. • 24.99±0.11 Ma (40Ar/39Ar on sanidine; this report) 12 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Table 1. Summary of 40Ar/39Ar dates for Toquima Range, Nevada, mineral separates. [≈, nearly equal to; Can., Canyon; Ma, million years ago] Sample Description Minerals Latitude Longitude Character of spectrum Date (Ma) and 1σ error DRS-85-122 Quartzite (prospect)1 White mica 38°42′36″N 116o58′47″W Preferred 40Ar loss 80.2±0.14 DRS-85-128 Porphyry clast (in Tjsi)2 Actinolite 38°42′30″N 116o58′12″W No plateau 80s DRS-85-176 Andesite clast (in Tjsi)3 Biotite 38°42′20″N 116o58′03″W Plateau 33.35±0.06 DRS-85-176 Andesite clast (in Tjsi)3 Plagioclase 38°42′20″N 116o58′03″W Preferred 40Ar loss 33.09±0.07 DRS-92-1 Tjc4 Biotite 38°43′24″N 117o01′10″W Plateau 32.74±0.05 DRS-92-1 Tjc4 Sanidine 38°43′24″N 117o01′10″W Preferred—Excess 40Ar 32.81±0.06 RH-TP-672 Tuff of Haystack Canyon Hornblende 38°42′35″N 116o41′30″W Plateau 29.70±0.12 RH-TP-672 Tuff of Haystack Canyon Sanidine 38°42′35″N 116o41′30″W Plateau 29.87±0.07 DRS-91-17 Clast in Tmb5 Biotite 38°30′33″N 116o51′25″W Plateau 27.51±0.05 DRS-91-17 Clast in Tmb5 Hornblende 38°30′33″N 116o51′25″W Preferred 40Ar loss 27.39±0.09 DRS-91-17 Clast in Tmb5 Sanidine 38°30′33″N 116o51′25″W Plateau 27.24±0.06 DRS-91-82 Tcc (Tccu)6 Biotite 38°41′11″N 116o49′41″W Plateau 27.35±0.05 DRS-91-82 Tcc (Tccu)6 Sanidine 38°41′11″N 116o49′41″W Plateau 27.36±0.06 DRS-91-92 Tmj breccia Biotite 38°41′20″N 116o50′49″W Plateau 27.32±0.04 DRS-91-31 Trc Biotite 38°30′51″N 116o51′10″W Disturbed Undetermined DRS-91-31 Trc Hornblende 38°30′51″N 116o51′10″W Plateau 26.85±0.14 DRS-91-31 Trc Sanidine 38°30′51″N 116o51′10″W Plateau 27.01±0.04 DRS-85-224 Trc Biotite 38°38′39″N 116o58′07″W Disturbed Undetermined DRS-85-224 Trc Sanidine 38°38′39″N 116o58′07″W Plateau 26.98±0.05 DRS-85-225 Trc Sanidine 38°36′27″N 116o50′26″W 40Ar loss or excess 40Ar ≈27.32±0.08 RH-TP-616 Ti Sanidine 38°42′27″N 116o48′55″W Preferred—Excess 40Ar 27.22±0.07 DRS-91-98 Tmj (Tmjv)7 Biotite 38°41′49″N 116o50′59″W Plateau 27.06±0.06 DRS-91-98 Tmj (Tmjv)7 Sanidine 38°41′49″N 116o50′59″W Preferred 40Ar loss 27.07±0.05 DRS-91-171 Tmj Biotite 38°42′07″N 116o50′38″W Plateau 27.10±0.04 DRS-91-171 Tmj Hornblende 38°42′07″N 116o50′38″W Preferred 40Ar loss 27.07+0.05 DRS-91-171 Tmj Sanidine 38°42′07″N 116o50′38″W Plateau 26.83+0.05 RH-TP-571 Tmj Biotite 38o42′15″N 116o50′01″W Plateau 27.02+0.07 RH-TP-571 Tmj Sanidine 38o42′15″N 116o50′01″W Plateau 27.00+0.06 RH-TP-583 Tmj Biotite 38o42′36″N 116o50′06″W Plateau 26.86+0.05 RH-TP-583 Tmj Hornblende 38o42′36″N 116o50′06″W Plateau 26.69+0.04 RH-TP-583 Tmj Sanidine 38o42′36″N 116o50′06″W Plateau 26.87+0.04 RH-TP-590 Tmj Biotite 38o43′30″N 116o49′10″W Plateau 26.99+0.06 RH-TP-590 Tmj Sanidine 38o43′30″N 116o49′10″W Plateau 26.85+0.04 RH-TP-644 Tmj Biotite 38o44′54″N 116o51′23″W Plateau 27.08+0.04 RH-TP-644 Tmj Hornblende 38o44′54″N 116o51′23″W Plateau 26.78+0.14 RH-TP-644 Tmj Sanidine 38o44′54″N 116o51′23″W Preferred 40Ar loss 26.83+0.07 RH-TP-646 Tmj Biotite 38o45′27″N 116o50′10″W Plateau 26.93+0.07 RH-TP-646 Tmj Sanidine 38o45′27″N 116o50′10″W Plateau 26.91+0.07 DRS-85-48 Tmj Biotite 38o41′19″N 116o59′18″W Plateau 26.89+0.05 DRS-85-48 Tmj Sanidine 38o41′19″N 116o59′18″W Plateau 26.86+0.04 DRS-85-78 Tmj(Tmjv)7 Biotite 38o43′27″N 116o58′39″W Plateau 26.85+0.05 DRS-85-78 Tmj(Tmjv)7 Sanidine 38o43′27″N 116o58′39″W Plateau 26.78+0.06 DRS-85-10 Tmj Biotite 38o41′57″N 116o55′56″W Plateau 26.79+0.04 DRS-85-10 Tmj Sanidine 38o41′57″N 116o55′56″W Preferred 40Ar loss 26.78+0.05 DRS-91-58A Trp Orthoclase 38o41′52″N 116o50′02″W Plateau 26.73+0.05 DRS-92-16 Tlt8 Biotite 38o42′29″N 116o50′48″W Disturbed Undetermined DRS-92-16 Tlt8 Sanidine 38o42′29″N 116o50′48″W Preferred—Excess 40Ar 26.47+0.05 DRS-85-27 Ty (Tpl)9 Biotite 38o42′19″N 116o53′33″W Plateau 27.36+0.05 DRS-85-27 Ty (Tpl)9 Hornblende 38o42′19″N 116o53′33″W Plateau 25.33+0.10 DRS-85-27 Ty (Tpl)9 Sanidine 38o42′19″N 116o53′33″W Plateau 25.49+0.05 DRS-92-59 Ty (Tpl)9 Biotite 38o42′23″N 116o52′57″W Disturbed ≈26.35+0.06 DRS-92-59 Ty (Tpl)9 Hornblende 38o42′23″N 116o52′57″W Plateau 25.71+0.15 DRS-92-59 Ty (Tpl)9 Orthoclase 38o42′23″N 116o52′57″W Plateau 25.57+0.05 DRS-91-74 Ty (tuffs of Road Can.)10 Biotite 38o51′29″N 116o51′04″W Disturbed 26.13+0.08 DRS-91-74 Ty (tuffs of Road Can.)10 Sanidine 38o51′29″N 116o51′04″W Plateau 25.61+0.05 DRS-85-54 Ty(Tspl)11 Biotite 38o43′03″N 116o52′35″W Disturbed ≈26.00+0.05 DRS-85-54 Ty(Tspl)11 Sanidine 38o43′03″N 116o52′35″W Plateau 25.13+0.19 RH-TP-659 Ty(Tcg)12 Biotite 38o42′54″N 116o49′15″W Plateau 24.88+0.05 RH-TP-659 Ty(Tcg)12 Hornblende 38o42′54″N 116o49′15″W Preferred—Excess 40Ar 24.85+0.18 RH-TP-659 Ty(Tcg)12 Sanidine 38o42′54″N 116o49′15″W Preferred—Excess 40Ar 24.99+0.11 1Mineralized quartzite, Gold Hill Formation (Cgq, Shawe, 1999b), from prospect dump. 2Porphyritic granite clast in intrusive phase of megabreccia of Jefferson Summit (Tjsi, Shawe, 1999b). 3Andesite clast in intrusive phase of megabreccia of Jefferson Summit (Tjsi, Shawe, 1999b). 4Vitrophyric matrix(?) at base of megabreccia of Jefferson (Tjc, Shawe, 1995). 5Clast in monolithologic megabreccia (Tmb, Shawe and others, 2000). 6Tuff of Corcoran Canyon (Tcc), upper unit (Shawe and others, 2000). 7Tuff of Mount Jefferson, vitrophyre unit (Tmjv, Shawe, 1999b). 8Biotite-rich layer in fine-grained tuffaceous sandstone-siltstone in volcaniclastic rocks of Little Table Mountain Tltl( , Shawe, 1999b). 9Tuff of Pipe Organ Spring, lower (Tpl, Shawe, 1999b), in Ty. 10Grayish-buff layered tuff in lower part of tuffs of Road Canyon, just northeast of our map area (Boden, 1986). 11Shingle Pass Tuff, lower (Tspl, Shawe, 1999b), in Ty. 12Tuff of Clipper Gap (Tcg, Shawe and others, 2000), in Ty. 40Ar/39Ar Geochronology of Volcanic Units 13

A B 35 35 RH-TP-659 Biotite RH-TP-659 Hornblende Tuff of Clipper Gap Tuff of Clipper Gap 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 Percent 39Ar released Percent ArK released K

C D 35 35 RH-TP-659 Sanidine DRS-85-54 Tuff of Clipper Gap Shingle Pass Tuff-lower 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

E F 35 35 DRS-85-54 Sanidine DRS-91-74 Biotite Shingle Pass Tuff-lower Tuffs of Road Canyon 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

G H 35 35 DRS-91-74 Sanidine DRS-92-59 Biotite Tuffs of Road Canyon Tuff of Pipe Organ Spring-lower 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Percent 39Ar released 39 K Percent ArK released Figure 2 (above and following pages). 40Ar/39Ar age spectra of minerals in volcanic rocks of the southern Toquima Range, Nye County, Nevada. Letters A through HHH correspond with the identifier in upper left of each view and link to discussion in text. 14 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

I J 35 35 DRS-92-59 Hornblende DRS-92-59 Orthoclase Tuff of Pipe Organ Spring-lower Tuff of Pipe Organ Spring-lower 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released K L 35 35 DRS-85-27 Biotite DRS-85-27 Hornblende Tuff of Pipe Organ Spring-lower Tuff of Pipe Organ Spring-lower 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

M N 35 35 DRS-85-27 Sanidine DRS-92-16 Biotite Tuff of Pipe Organ Spring-lower Volcaniclastic rocks of Little Table Mountain 30 30

25 25

Apparent age (Ma) APparent age (Ma) 20 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 Percent 39Ar released Percent ArK released K

O P 35 35 DRS-92-16 Sanidine DRS-91-58A Orthoclase Volcaniclastic rocks of Little Table Mountain Rhyolite plug 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released Figure 2. 40Ar/39Ar age spectra of minerals in volcanic rocks of the southern Toquima Range, Nye County, Nevada. Letters A through HHH correspond with the identifier in upper left of each view and link to discussion in text.—Continued 40Ar/39Ar Geochronology of Volcanic Units 15

Q R 35 35 DRS-85-10 Biotite DRS-85-10 Sanidine Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Percent 39Ar released 39 K Percent ArK released S T 35 35 DRS-85-78 Biotite DRS-85-78 Sanidine Tuff of Mount Jefferson-vitrophyre Tuff of Mount Jefferson-vitrophyre 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

U V 35 35 DRS-85-48 Biotite DRS-85-48 Sanidine Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

W X 35 35 RH-TP-646 Biotite RH-TP-646 Sanidine Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

Y Z 35 35 RH-TP-644 Biotite RH-TP-644 Hornblende Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

AA BB 35 35 RH-TP-644 Sanidine RH-TP-590 Biotite Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

CC DD 35 35 RH-TP-590 Sanidine RH-TP-583 Biotite Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

EE FF 35 35 RH-TP-583 Hornblende RH-TP-583 Sanidine Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

GG HH 35 35 RH-TP-571 Biotite RH-TP-571 Sanidine Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma)

Apparent age (Ma) 20 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

II JJ 35 35 DRS-91-171 Biotite DRS-91-171 Hornblende Tuff of Mount Jefferson Tuff of Mount Jefferson 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

KK LL 35 35 DRS-91-171 Sanidine DRS-91-98 Biotite Tuff of Mount Jefferson Tuff of Mount Jefferson-vitrophyre 30 30

25 25

Apparent age (Ma)

20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

MM NN 35 35 DRS-91-98 Sanidine RH-TP-616 Sanidine Tuff of Mount Jefferson-vitrophyre Isom-type ash-flow tuff 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

OO PP 35 35 DRS-85-225 Sanidine DRS-85-224 Biotite Tuff of Ryecroft Canyon Tuff of Ryecroft Canyon 30 30

(Ma)

25 25

pparent age

A A 20 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

QQ RR 35 35 DRS-85-224 Sanidine DRS-91-31 Biotite Tuff of Ryecroft Canyon Tuff of Ryecroft Canyon 30 30

(Ma) (Ma)

25 25

pparent age pparent age A 20 A 20

15 0 10 20 30 40 50 60 70 80 90 100 150 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

SS TT 35 35 DRS-91-31 Hornblende DRS-91-31 Sanidine Tuff of Ryecroft Canyon Tuff of Ryecroft Canyon 30 30

(Ma) (Ma)

25 25

pparent age pparent age A 20 A 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100

39 39 Percent ArK released Percent ArK released UU VV 35 35 DRS-91-92 Biotite DRS-91-82 Biotite Tuff of Mount Jefferson-breccia Tuff of Corcoran Canyon-upper unit 30 30

(Ma) (Ma)

25 25

pparent age pparent age A 20 A 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100

39 39 Percent ArK released Percent ArK released Figure 2. 40Ar/39Ar age spectra of minerals in volcanic rocks of the southern Toquima Range, Nye County, Nevada. Letters A through HHH correspond with the identifier in upper left of each view and link to discussion in text.—Continued 40Ar/39Ar Geochronology of Volcanic Units 19

WW XX 35 35 DRS-91-82 Sanidine DRS-91-17 Biotite Tuff of Corcoran Canyon Clast in monolithologic megabreccia 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released YY ZZ 35 35 DRS-91-17 Hornblende DRS-91-17 Sanidine Clast in monolithologic breccia Clast in monolithologic breccia 30 30

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

AAA BBB 35 35 RH-TP-672 Hornblende RH-TP-672 Sanidine Tuff of Haystack Canyon Tuff of Haystack Canyon 30 30

25 25

Apparent age (Ma) Apparent age (Ma) 20 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released

CCC DDD 35 35

DRS-92-1 Biotite 30 30 DRS-92-1 Sanidine Megabreccia of Jefferson-basal vitrophyric matrix Megabreccia of Jefferson-basal vitrophyric matrix

25 25

Apparent age (Ma)

20 Apparent age (Ma) 20

EEE FFF 35 35

DRS-85-176 Biotite 30 Andesite clast in megabreccia of Jefferson Summit 30 DRS-85-176 Plagioclase Andesite clast in megabreccia of Jefferson Summit

25 25

Apparent age (Ma) 20 Apparent age (Ma) 20

15 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released GGG HHH 100 85 DRS-85-128 Actinolite Porphyritic granite clast in megabreccia of Jefferson Summit 75 90 DRS-85-122 White mica 65 Gold Hill Formation-mineralized quartzite 80 55

45 70 35

Apparent age (Ma) Apparent age (Ma) 60 25

50 15 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 39 39 Percent ArK released Percent ArK released Figure 2. 40Ar/39Ar age spectra of minerals in volcanic rocks of the southern Toquima Range, Nye County, Nevada. Letters A through HHH correspond with the identifier in upper left of each view and link to discussion in text.—Continued

A sample from the lower part of the Shingle Pass Tuff respectively. The age spread among these analyses may reflect (Tsp) (DRS-85-54) yielded biotite and sanidine separates. The real age differences or routine analytical error. Our preference biotite age spectrum (fig. 2D) is slightly disturbed and includes is to average these four dates to obtain an average arithmetic an excess 40Ar hump, likely the result of minor secondary age of 25.53±0.16 Ma for the tuff of Pipe Organ Spring. chlorite. Analytical issues caused the sanidine to produce a • 25.33±0.10 (40Ar/39Ar on hornblende; this report) low isotopic signal; however, the sample yielded a plateau (fig. 2E) that includes more than 70.7 percent of the released • 25.36±0.05 (40Ar/39Ar on biotite; this report) 39 Ar with a date of 25.13±0.19 Ma, which is our best estimate • 25.49±0.05 Ma (40Ar/39Ar on sanidine; this report) for the age of the unit. • 25.53±0.16 Ma (40Ar/39 average age; this report) • 25.13±0.19 Ma (40Ar/39Ar on sanidine; this report) • 25.57±0.05 Ma (40Ar/39Ar on orthoclase; this report) A sample of the tuff of Road Canyon (DRS-91-74; 40 39 fig. 1) collected in Road Canyon 12 km north of our map • 25.71±0.15 Ma ( Ar/ Ar on hornblende; this report) area yielded biotite and sanidine separates. The biotite argon Biotite (fig. N2 ) and sanidine (fig. O2 ) separates from spectrum (fig. 2F) is disturbed but the sanidine (fig. G2 ) sample DRS-92-16 of the Little Table Mountain unit (Tlt) yielded a plateau age of 25.61±0.05 Ma, which is our best yielded disturbed age spectra. The biotite date is unreliable. estimate for the age of the tuff. However, the sanidine spectrum, although it indicates minor • 25.61±0.05 Ma (40Ar/39Ar on sanidine; this report) excess 40Ar, defines an apparent age of 26.47±0.05 Ma in its Two samples of the tuff of Pipe Organ Spring (Ty) low-age segment, which we consider to be the best estimate were analyzed. Sample DRS-92-59 yielded orthoclase, of the age of the unit. hornblende, and biotite separates. The biotite spectrum • 26.47±0.05 Ma (40Ar/39Ar on sanidine; this report) indicates excess 40Ar (fig. 2H); the hornblende (fig. I2 ) and An orthoclase separate from a rhyolite plug (Trp), sample orthoclase (fig. J2 ) spectra include plateaus of 25.71±0.15 Ma DRS-91-58A, yielded an argon plateau date of 26.73±0.05 Ma and 25.57±0.05 Ma, respectively. Sample DRS-85-27 biotite (fig. 2K), hornblende (fig. L2 ) and sanidine (fig. M2 ) plateau (fig. 2P), our accepted date for alteration of the intrusion. dates are 25.36±0.05, 25.33±0.10, and 25.49±0.05 Ma, • 26.73±0.05 Ma (40Ar/39Ar on orthoclase; this report) 40Ar/39Ar Geochronology of Volcanic Units 21

Twenty-one of the dated mineral separates (sanidine, and 27.36±0.06 (1σ) Ma, respectively. The average of these biotite, and hornblende) from 10 Mount Jefferson samples range dates is our preferred age for eruption of the Corcoran in age from 27.07 Ma to 26.69; an additional Mount Jefferson Canyon tuff. sample is a vitrophyre that produced sanidine and biotite • 27.35±0.05 (1σ) Ma (40Ar/39Ar on biotite; this report) separates with apparent ages in this same range (figs. 2Q–MM). 40 39 Of the 23 samples, 18 yield plateau age spectra with a mean age • 27.36±0.06 (1σ) Ma ( Ar/ Ar on sanidine; this report) of 26.90±0.10 (1σ) Ma. Of the 5 samples that did not produce Biotite (fig. XX2 ), hornblende (fig. YY2 ), and sanidine plateaus, 4 are sanidine that indicate gradually increasing (fig. 2ZZ) separates were recovered from and 40Ar/39Ar ages age with increasing release temperature, which is a common determined for a sample (DRS-91-17) of the monolithologic characteristic of sanidine age spectra; our preferred ages for megabreccia (Tmb). The hornblende spectrum indicates 40Ar these 4 samples are also coincident with the age range defined loss and defines a near plateau age of 27.39±0.09 (1σ) Ma by the 18 samples included in the mean age. The fifth sample (fig. 2YY). Biotite and sanidine separates yielded plateaus with is hornblende, separated from vitrophyre, that produced an 40Ar apparent ages of 27.51±0.05 (1σ) and 27.24±0.06 (1σ) Ma, loss spectrum that steps up in apparent age to 27.07 Ma, which respectively. The biotite and sanidine dates are statistically is identical to the age of coexisting biotite from the vitrophyre. distinct and the hornblende date is intermediate. The average The average of all 21 apparent ages is 26.90±0.11 (1σ) Ma. of these three dates, 27.38±0.14 (1σ) Ma, probably represents The 0.38-m.y. range of ages among the 21 samples may the best estimate of the age of this unit. Alternatively, because represent analytical error or, alternatively, may reflect the true the biotite and sanidine ages are statistically distinct their duration of eruptive activity responsible for the tuff of Mount age discordance may indicate geologic processes rather than Jefferson (Tmj). analytical error. Thus, the biotite apparent age may represent • 26.90±0.11 (1σ) Ma (mean age 40Ar/39Ar on tuff; the best age of the monolithologic megabreccia (Tmb) because 40 this report) the amphibole and sanidine age spectra both indicate Ar loss. 40 39 • 27.07 Ma (40Ar/39Ar on hornblende; this report) • 27.24±0.06 (1σ) Ma ( Ar/ Ar on sanidine; this report) 40 39 Sanidine from sample RH-TP-616 collected from the • 27.38±0.14 (1σ) Ma (average age, Ar/ Ar on sanidine; Isom-type ash-flow tuff (Ti) defines a disturbed age spectrum this report) that indicates excess 40Ar. The low-age part of the age- • 27.39±0.09 (1σ) Ma ( 40Ar/39Ar on hornblende; this report) spectrum saddle yields an apparent age of 27.22±0.07 (1σ) • 27.51±0.05 (1σ) (40Ar/39Ar on biotite; this report) Ma (fig. 2NN). However, the presence of excess 40Ar suggests that the preferred age may be older than the actual Sample RH-TP-672 (fig. 1) was collected in the eruption age. nearby Monitor Range and represents the informally named tuff of Haystack Canyon (R.F. Hardyman, oral commun., 40 39 • 27.22±0.07 (1σ) Ma ( Ar/ Ar on tuff; this report) 2012). Hornblende (fig. AAA2 ) and sanidine (fig. BBB2 ) Three samples of the tuff of Ryecroft Canyon (Trc) separates yielded concordant dates of 27.70±0.12 (1σ) and yielded sanidine (fig. OO2 ) (DRS-85-225), biotite (fig. PP2 ) 27.87±0.07 (1σ) Ma, respectively. The average apparent age and sanidine (fig. QQ2 ) (DRS-85-224), and biotite (fig. RR2 ), of 27.79±0.10 (1σ) Ma is our estimate of the age of the tuff. hornblende (fig. SS2 ), and sanidine (fig. TT2 ) (DRS-91-31) • 27.79±0.10 (1σ) Ma (average age, 40Ar/39Ar on tuff; separates that were analyzed. Both biotite age spectra are this report) strongly disturbed and produce indeterminate results. The • 27.70±0.12 (1σ) (40Ar/39Ar on hornblende; this report) sanidine age spectrum for sample DRS-85-225 is difficult to interpret because it reflects characteristics of either40 Ar loss or • 27.87±0.07 (1σ) Ma (40Ar/39Ar on sanidine; this report) excess 40Ar. Sanidine from sample DRS-85-224, and sanidine A sample of Jefferson Canyon megabreccia (Tjc) and hornblende from sample DRS-91-31 produced plateau (DRS-92-1) yielded a biotite plateau age (fig. CCC2 ) of spectra with an average age of 26.95±0.08 (1σ) Ma. 32.74±0.05 (1σ) Ma and a sanidine preferred age (fig. DDD2 ) • 26.95±0.08 (1σ) Ma (average age, 40Ar/39Ar on tuff; of 32.81±0.06 (1σ) Ma. The sanidine age spectrum is disturbed 40 40 this report) and indicates either Ar loss or excess Ar. Therefore the biotite date is our best estimate for the age of this unit. Biotite in sample DRS-91-92 from a breccia clast 40 39 contained in the tuff of Mount Jefferson (Tmj) yielded an • 32.74±0.05 (1σ) Ma ( Ar/ Ar on biotite; this report) argon spectrum (fig. UU2 ) indicative of minor excess 40Ar but • 32.81±0.06 (1σ) Ma (40Ar/39Ar on sanidine; this report) includes a plateau with an apparent age of 27.32±0.04 (1σ) Ma. Sample DRS-85-176 is from an andesite porphyry clast in We interpret this plateau to be the age of the clast and therefore the intrusive phase of megabreccia of Jefferson Summit (Tjs) a maximum age for the enclosing tuff. from which biotite (fig. EEE2 ) and plagioclase (fig. 2FFF) • 27.32±0.04 (1σ) Ma (40Ar/39Ar on biotite; this report) separates were obtained. The plagioclase age spectrum is Sample DRS-91-82, tuff of Corcoran Canyon (Tcc), disturbed, but the biotite produced an age spectrum with a yielded biotite (fig. VV2 ) and sanidine (fig. WW2 ) separates that plateau age of 33.35±0.06 (1σ) Ma, our accepted age. produced concordant apparent plateau ages of 27.35±0.05 (1σ) • 33.35±0.06 (1σ) Ma (40Ar/39Ar on biotite; this report) 22 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Sample DRS-85-128 represents clasts in the intrusive Trail Canyon by Boden (1986), which we believe is part of phase of the megabreccia of Jefferson Summit (Tjs). the tuff of Mount Jefferson), tuff of Ryecroft Canyon (Trc) Actinolite from DRS-85-128 yielded a disturbed argon (3 samples), tuff of Corcoran Canyon (Tcc) (2 samples), and spectrum (fig.2GGG) with an apparent Late Cretaceous age. megabreccia of Jefferson Canyon (1 sample). The megabreccia Argon derived from muscovite in DRS-85-122 produced of Jefferson Canyon (Tjc) was described by Boden (1986) an argon-loss spectrum (fig. HHH2 ) with an interpreted age as the megabreccia of Dry Canyon and correlated by Henry of 80.2±0.1 (1σ) Ma, which is a reasonable estimate for the (1997) with a 32.3 Ma caldera underlying Big Smoky Valley. cooling age of the muscovite. • 80.2±0.1 (1σ) Ma (40Ar/39Ar on muscovite; this report) Results of Phenocryst Analyses Phenocryst compositions are discussed in subsequent Phenocryst Compositions as sections by individual volcanic unit: megabreccia of Jefferson Canyon (Tjc), tuff of Corcoran Canyon (Tcc), tuff of Ryecroft Determined by Electron Microprobe Canyon (Trc), tuff of Mount Jefferson (Tmj), Isom-type tuff (Ti), and Bates Mountain Tuff (Ti). Phenocryst composition Analytical Methods, Mineral Structural variations may mimic the compositional variations of host Formula Calculations, and Samples Analyzed magmas arrayed in vertically zoned reservoirs; during single eruptions magma may have been derived from multiple zones. Polished thin sections of selected samples were prepared In most cases, because of the relatively limited number of to determine compositions of plagioclase, sanidine, biotite, samples studied and the relative uncertainty of each sample’s hornblende, clinopyroxene, and orthopyroxene phenocrysts stratigraphic position (general position estimated for tuff of by electron microprobe analysis. Not all of these minerals Mount Jefferson samples), interpreting the nature and extent of were present or analyzed in each of the samples examined. magma evolution and eruptive histories are possible to a limited Resulting microprobe analyses were used to calculate mineral extent only. However, the data provide evidence that in some of structural formulas. the formations studied, conditions prevailing during phenocryst Phenocryst compositions were determined using a crystallization varied between eruptive episodes, attesting JEOL 8900® electron microprobe with 5 wavelength- to likely derivation of magma from different levels in zoned dispersive crystal spectrometers, 5–20 micrometer (μm) beam, reservoirs. Although geologic evidence implies more than one 15 kilovolt (kV) accelerating voltage, and 20 nanoampere cooling unit (representing discrete eruptive episodes) in some (nA) beam current were used to make 20-second analyses on formations, and there is petrographic evidence of compositional numerous grains of each mineral species. Analyzed spots were variation in magma during an episode, the data are generally at grain cores and rims, and in some instances at intermediate insufficient to define the nature and extent of magma evolution spots to ensure that the full composition range of each mineral during the petrogenesis of individual ash-flow tuffs. However, was recorded. In tables of analytical data (appendixes 2–8), mineral composition data define magma composition “Probe sample no.” entries ending in “1” identify grain core characteristics pertinent to the histories of the different analyses, whereas “2” indicates grain rim analyses, and “3” or formations, and the data bear on proposed unit correlations. “4” indicate analyses of intermediate parts of grains. Locations of samples for which mineral compositions were Microprobe determinations report total iron in biotite determined are shown on plate 1 and figure 1. in the ferrous (Fe2+) state. Prior to structural formula calculation total iron was partitioned to Fe2+ and Fe3+ by Megabreccia of Jefferson Canyon (Unit Tjc) assuming Fe2+/(Fe2++Fe3+) = 0.85 (Dodge and others, 1969);

H2O abundances were determined by stoichiometry by We determined phenocryst compositions in only one assuming 24 anions (O, OH, F, Cl). sample (vitrophyre, DRS-92-1; figs. 3–6) of the megabreccia Microprobe determinations report total iron in amphibole of Jefferson Canyon (Tjc). The vitrophyric sample was in the ferrous (Fe2+) state. As part of structural formula collected where the rock appears to be a basal chilled calculations, total iron was partitioned to Fe2+ and Fe3+ by ash matrix of the megabreccia. Accordingly, the ages of charge balancing; H2O abundances were determined by its contained phenocrysts probably define the age of the stoichiometry assuming 24 anions (O, OH, F, Cl). Amphibole vitrophyre and the associated megabreccia. Alternatively, the names were assigned according to the classification of Leake vitrophyre may constitute a large clast derived from an older and others (1997). Compositions of each of the minerals unit, in which case phenocrysts would not be representative analyzed are presented in variation diagrams (figs. 3–27). of the megabreccia. The compositions of biotite, amphibole, Several volcanic units were selected for phenocryst and pyroxene phenocrysts were determined by microprobe composition determinations in order to confirm the identity analysis and are compared here to those in the tuff of Mount or correlation of their host units. Studied were Isom-type Jefferson (Tmj), described in later paragraphs. tuff (Ti) (3 samples), Bates Mountain Tuff (Ty) (3 samples), Biotite compositions shown in figure 3 are virtually tuff of Mount Jefferson (Tmj) (8 samples, identified in the identical to those of Mg-rich biotites in samples from the next section, including 5 from a unit identified as tuff of lower part of the tuff of Mount Jefferson (see later discussion Phenocryst Compositions as Determined by Electron Microprobe 23 of fig. 12) and are more Mg-rich than samples from the upper Ca part of the tuff of Mount Jefferson (see later discussion of figs. 13, 14). The similarity of biotite compositions suggests that the megabreccia of Jefferson Canyon (Tjc) is akin to the lower part of the tuff of Mount Jefferson. The composition of one biotite in the vitrophyre of sample DRS-92-1 (fig. 3), which plots off the general trend, may represent an inaccurate analysis. Compositions of hornblende in sample DRS-92-1 (fig. 4) lie along the less Ca-rich hornblende composition trend defined for tuff of Mount Jefferson (Tmj) samples (see later discussion of fig. 16), and appear to be most akin to the older (lower) part of the tuff of Mount Jefferson. Amphibole in the sample is composed of edenite and pargasite/ magnesiohastingsite (see later discussion of fig. 5). Compositions of augite in the sample of the megabreccia of Jefferson Canyon (Tjc) (DRS-92-1, fig. 6) are virtually identical to those of clinopyroxene in tuff of Mount Jefferson samples (see subsequent discussion of fig. 19). Compositional similarities among biotite, hornblende, 10Ti 2Mg/(Mg+Fe2+) EXPLANATION and augite in the megabreccia of Jefferson Canyon (Tjc) and Cores, megabreccia of Jefferson Canyon DRS-92-1 those in the tuff of Mount Jefferson (Tmj) suggest that the Rims, megabreccia of Jefferson Canyon DRS-92-1 two units had a common magma source. If this correlation is Figure 4. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing correct, then the inference that the megabreccia is related to relative cation abundances in hornblende of one sample, southern the Mount Jefferson caldera, as suggested earlier by Shawe Toquima Range, Nye County, Nevada. (Sample DRS-92-1; unit Tgs (1995, 1999b) and by Shawe, Hardyman, and Byers (2000), of Shawe, 1995) is corroborated. The 32 Ma dates for the megabreccia of Jefferson Canyon obtained by Boden (1986, 1992), Henry incorporated as clasts in the younger megabreccia. 40Ar/39Ar (1997), and Shawe (1999b) may represent older material dating of the sample of vitrophyre (DRS-92-1) would clarify Mg these relationships.

Tuff of Corcoran Canyon (Unit Tcc)

Compositions of biotite were determined for two samples of the tuff of Corcoran Canyon (unit Tcc). Sample DRS-91-59 is from the lower member and sample DRS-91-89 is from the upper member. Biotite compositions form two well-defined clusters (fig. 7); biotite of DRS-91-89 is relatively enriched in Mg-Fe2++Mn, whereas biotite of DRS-91-59 is more enriched in Al3++Fe3++Ti. The upper member sample (DRS-91-89) seems to have crystallized from a more mafic magma than the sample from the lower member (DRS-91-59), which suggests that the earlier eruption may have come from the upper, more evolved part of a compositionally stratified magma reservoir, whereas the later eruption came from the lower, less evolved part. Compositions of biotite phenocrysts in the tuff of Corcoran Canyon (Tcc) are similar to those in the tuffs Tmj Trc Al 3+ + Fe3+ + Ti Fe2+ + Mn of Mount Jefferson ( ), and of Ryecroft Canyon ( ), EXPLANATION although compositions of biotite phenocrysts in all three units Cores, megabreccia of Jefferson Canyon DRS-92-1 suggest compositional variation within their source reservoirs. Rims, megabreccia of Jefferson Canyon DRS-92-1 Inferred magma composition variation may indicate Figure 3. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing compositionally stratified magma reservoirs or periodic relative cation abundances in biotite of one sample, southern eruptions from differently evolved magmas, or both. Overall Toquima Range, Nye County, Nevada (Sample DRS-92-1; unit Tgs biotite compositional similarity among the three units suggests of Shawe, 1995) that they had similar petrogenetic histories. 24 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

0.85 Edenite Pargasite/magnesiohastingsite 0.80

0.75

0.70 ) 2+

0.65 Mg/(Mg+Fe 0.60

0.55

0.50 Ferroedenite Ferropargasite/Hastingsite

0.45 7.5 7.3 7.1 6.9 6.7 6.5 6.3 6.1 5.9 5.7 5.5 Si in formula EXPLANATION Cores, megabreccia of Jefferson Canyon DRS-92-1 Rims, megabreccia of Jefferson Canyon DRS-92-1 Figure 5. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of one sample, southern Toquima Range, Nye County, Nevada. (Sample DRS-92-1; unit Tgs of Shawe, 1995)

WO Mg

Diopside Hedenbergite

Augite

Hypersthene

EN FS Al 3+ + Fe3+ + Ti Fe2+ + Mn EXPLANATION EXPLANATION Cores, megabreccia of Jefferson Canyon DRS-92-1 Cores, tuff of Corcoran Canyon, upper DRS-91-89 Rims, megabreccia of Jefferson Canyon DRS-92-1 Rims, tuff of Corcoran Canyon, upper DRS-91-89 Figure 6. Ternary diagram showing proportions of wollastonite, Cores, tuff of Corcoran Canyon, lower DRS-91-59 Rims, tuff of Corcoran Canyon, lower DRS-91-59 enstatite, and ferrosilite in clinopyroxene of one sample, southern Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing Toquima Range, Nye County, Nevada; EN, enstatite; FS, ferrosilite; Figure 7. relative cation abundances in biotite of two samples, southern WO, wollastonite. (Sample DRS-92-1; unit Tgc of Shawe, 1995) Toquima Range, Nye County, Nevada. (Samples DRS-91-89 and DRS-91-59; unit Tcc of Shawe, Hardyman, and Byers, 2000) Phenocryst Compositions as Determined by Electron Microprobe 25

No composition data were obtained for hornblende part of a zoned reservoir and later eruption may have come or pyroxene in the tuff of Corcoran Canyon (Tcc) because from lower in the reservoir. Compositions of biotite in no unaltered phenocrysts could be identified. Similarly, no samples from the tuff of Ryecroft Canyon are also nearly analyses of feldspar phenocrysts in samples DRS-91-59 and coincident with those of biotite in the tuff of Mount Jefferson DRS-91-89 from the tuff of Corcoran Canyon were obtained. (Tmj), which suggests their possible cogenesis. However, compositions of biotite in the tuff of Ryecroft Canyon are less Fe-Mn rich and more Mg rich, which suggests that Tuff of Ryecroft Canyon (Unit Trc) magma represented by the slightly younger tuff of Mount Jefferson was less evolved than magma represented by the We determined compositions of biotite and amphibole tuff of Ryecroft Canyon. in samples DRS-91-19, DRS-91-21, and DRS-91-24 of Compositions of amphiboles (fig. )9 in samples the tuff of Ryecroft Canyon (Trc). Sample DRS-91-19 was DRS-91-19, DRS-91-21, and DRS-91-24 of the tuff of collected near the base of exposed tuff of Ryecroft Canyon; Ryecroft Canyon (Trc) form a linear trend that extends from samples DRS-91-21 and DRS-91-24 came from relatively a separate cluster of DRS-91-19 analyses with relatively higher stratigraphic positions, possibly less than about 90 m Ca- to Mg-Fe–rich compositions (mostly edenite) to a higher; disparate compaction foliation attitudes (suggestive broad cluster of DRS-91-21 and DRS-91-24 compositions of fault disruption) in the sampled area precluded more (mostly pargasite/magnesiohastingsite, fig. 10) that are accurate assessment of relative stratigraphic position. relatively enriched in Ti. These compositional variations Compositions of biotite in samples DRS-91-21 and suggest that sample DRS-91-19, from near the base of the DRS-91-24 (fig. 8) form nearly coincident well-defined trends, Ryecroft Canyon, crystallized from a less evolved magma whereas those in sample DRS-91-19 (fig. 8) cluster near the than did samples DRS-91-21 and DRS-91-24 from several Fe2++Mn-rich (hence more silicic) end of the DRS-91-21 hundred meters higher in the formation. The variations and DRS-91-24 compositional arrays. Apparently, prior to suggest eruption of discrete magma batches, either from a eruption the source magma became compositionally stratified zoned magma reservoir or from distinct reservoirs having such that the initial eruption may have been from the upper different compositions

Mg Ca

Al 3+ + Fe3+ + Ti Fe2+ + Mn 10Ti 2Mg/(Mg+Fe2+) EXPLANATION EXPLANATION Cores, tuff of Ryecroft Canyon DRS-91-21 Cores, tuff of Ryecroft Canyon DRS-91-21 Rims, tuff of Ryecroft Canyon DRS-91-21 Rims, tuff of Ryecroft Canyon DRS-91-21 Cores, tuff of Ryecroft Canyon DRS-91-24 Cores, tuff of Ryecroft Canyon DRS-91-24 Rims, tuff of Ryecroft Canyon DRS-91-24 Rims, tuff of Ryecroft Canyon DRS-91-24 Cores, tuff of Ryecroft Canyon DRS-91-19 Cores, tuff of Ryecroft Canyon DRS-91-19 Rims, tuff of Ryecroft Canyon DRS-91-19 Rims, tuff of Ryecroft Canyon DRS-91-19 Figure 8. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing Figure 9. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in biotite of three samples, southern relative cation abundances in hornblende of three samples, Toquima Range, Nye County, Nevada. (Samples DRS-91-21, southern Toquima Range, Nye County, Nevada. (Samples DRS-91-24, and DRS-91-19; unit Trc of Shawe, Hardyman, and DRS-91-21, DRS-91-24, and DRS-91-19; unit Trc of Shawe, 1999b) Byers, 2000) 26 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

0.85 Edenite Pargasite/magnesiohastingsite

0.80

0.75

0.70 ) + 2

F e 0.65 g + M ( g /

M 0.60

0.55

0.50 Ferroedenite Ferropargasite/Hastingsite

0.45 7.5 7.3 7.1 6.9 6.7 6.5 6.3 6.1 5.9 5.7 5.5 Si in formula EXPLANATION Cores, tuff of Ryecroft Canyon DRS-91-21 Rims, tuff of Ryecroft Canyon DRS-91-24 Rims, tuff of Ryecroft Canyon DRS-91-21 Cores, tuff of Ryecroft Canyon DRS-91-19 Cores, tuff of Ryecroft Canyon DRS-91-24 Rims, tuff of Ryecroft Canyon DRS-91-19 Figure 10. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of three samples, southern Toquima Range, Nye County, Nevada. (Samples DRS-91-21, DRS-91-24, and DRS-91-19; unit Trc of Shawe, 1999b)

We determined compositions of feldspar phenocrysts in An samples DRS-91-21 and DRS-91-24 of the tuff of Ryecroft Canyon Trc (fig. 11). Sanidine compositions are similar in the two samples and are slightly enriched in albite in sample DRS-91-24 relative to sample DRS-91-21. Plagioclase compositions in the two samples are similar, except that some plagioclase in sample DRS-91-21 is enriched in CaO. Also, compositions of plagioclase in the tuff of Mount Jefferson (Tmj) (see later discussion of fig. 20) and tuff of Ryecroft Canyon (fig. 11) are indistinguishable, and sanidine compositions are similar, which suggests similar petrogenetic histories for magma represented by the two tuffs.

Tuff of Mount Jefferson (Unit Tmj)

The tuff of Mount Jefferson (Tmj) provided the largest set of samples for which phenocryst compositions were determined, including samples from the unit we mapped as tuff of Mount Jefferson (3 samples analyzed) and the unit Ab EXPLANATION Or mapped by Boden (1986, 1992) as tuff of Trail Canyon Cores, tuff of Ryecroft Canyon DRS-91-21 Rims, tuff of Ryecroft Canyon DRS-91-21 (5 samples analyzed). Whole-rock chemistry and phenocryst Cores, tuff of Ryecroft Canyon DRS-91-24 index (PI) data for the tuff of Mount Jefferson (unit (Tmj) Rims, tuff of Ryecroft Canyon DRS-91-24 of Shawe, 1999b), do not vary systematically relative to Figure 11. Ternary diagram showing molecular end-member stratigraphic position. Nonsystematic data of this sort are proportions of albite, anorthite, and orthoclase feldspars in two consistent with derivation of successive ash flow eruptions by samples, southern Toquima Range, Nye County, Nevada. (Samples nonsystematically tapping various levels within a vertically DRS-91-21 and DRS-91-24; unit Trc of Shawe, 1999b; Ab, albite, zoned magma reservoir, or by top-down eruption from a An, anorthite; Or, orthoclase) Phenocryst Compositions as Determined by Electron Microprobe 27 nonsystematically zoned reservoir. The eight analyzed samples Mg from the tuff of Mount Jefferson were collected from the upper 700 m of the (intracaldera) principal member of the formation. Because this member is probably more than 2,000 m thick (Shawe, 1999b), these analyses depict only the latest intervals of its petrogenetic history. Estimates of relative stratigraphic position suggest that samples (DRS-85-44, DRS-85-203, and DRS-85-204) collected on the west side of the Soldier Spring fault are likely from the middle part of the principal member. Samples (DRS-92-20, DRS-85-199, DRS-85-197, DRS-91-168, and DRS-91-169), collected on the east side of the Soldier Spring fault, are from the upper part of the principal member. We determined the compositions of biotite in eight samples (fig. 12—DRS-85-44, DRS-85-203, DRS-85-204; fig. 13—DRS-92-20, DRS-85-199, DRS-85-197, and fig. 14— DRS-91-168, DRS-91-169). Biotite in the two lowest samples (DRS-85-44 and DRS-85-203, fig. 12) has compositions Al 3+ + Fe3+ + Ti Fe2+ + Mn that cluster in a small field with somewhat more Mg than EXPLANATION 2+ Cores, tuff of Mt. Jefferson DRS-92-20 Fe +Mn. Biotite from the stratigraphically next higher sample Rims, tuff of Mt. Jefferson DRS-92-20 (DRS-85-204, fig. 12) has similar compositions, except that Cores, tuff of Mt. Jefferson DRS-85-199 Rims, tuff of Mt. Jefferson DRS-85-199 2+ one analysis indicates slightly less Mg than Fe +Mn. Samples Cores, tuff of Mt. Jefferson DRS-85-197 apparently stratigraphically higher (fig. 13—DRS-92-20, Rims, tuff of Mt. Jefferson DRS-85-197 DRS-85-199, and DRS-85-197; and fig. 14—DRS-91-168, Figure 13. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn and DRS-91-169) have compositions that define two fields, showing relative cation abundances in biotite of three samples, one similar to those of the lower three samples, and a second southern Toquima Range, Nye County, Nevada. (Samples DRS-92-20, that indicates compositions with slightly less Mg than DRS-85-199, and DRS-85-197; unit Tmj of Shawe, 1995)

Mg Mg

Al 3+ + Fe3+ + Ti Fe2+ + Mn Al 3+ + Fe3+ + Ti Fe2+ + Mn EXPLANATION EXPLANATION Cores, tuff of Mt. Jefferson DRS-85-204 Cores, tuff of Mt. Jefferson DRS-91-169 Rims, tuff of Mt. Jefferson DRS-85-204 Cores, tuff of Mt. Jefferson DRS-85-203 Rims, tuff of Mt. Jefferson DRS-91-169 Rims, tuff of Mt. Jefferson DRS-85-203 Cores, tuff of Mt. Jefferson DRS-91-168 Cores, tuff of Mt. Jefferson DRS-85-44 Rims, tuff of Mt. Jefferson DRS-91-168 Rims, tuff of Mt. Jefferson DRS-85-44 Figure 14. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn Figure 12. Ternary diagram of Mg–Al3++Fe3++Ti–Fe2++Mn showing showing relative cation abundances in biotite of two samples, relative cation abundances in biotite of three samples, southern southern Toquima Range, Nye County, Nevada. (Samples DRS-91- Toquima Range, Nevada. (Samples DRS-85-204, DRS-85-203, and 169 and DRS-91-168; unit Tmj of Shawe, 1995) DRS-85-44; unit Tmi of Shawe, 1995) 28 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Fe2++Mn. The biotite data for all eight samples suggest that Ca initial eruptions were derived from a layer relatively enriched in Mg- in a normally zoned two-layer reservoir and a higher, more evolved, layer relatively enriched in Fe; subsequent eruptions may represent a mixture of both layers. Compositions of amphibole phenocrysts in seven samples of the principal member of the tuff of Mount Jefferson (Tmj) define two trends (fig. 15—DRS-85-44, DRS-85-203, DRS-85-204, DRS-92-20, DRS-85-199, DRS-85-197, and DRS-91-169). Two samples, DRS-85-199 and DRS-85-197 (fig. 16) from near the top of the formation, characterize the two trends most distinctly. Compositions of amphibole phenocrysts in sample DRS-92-20 (figs. 16, 17) are coincident with only the more Ca-rich of the two trends. The two compositional groups most diagnostic of the tuff of Mount Jefferson (the majority of analyses, fig. 15) suggest that successive eruptions tapped both layers of a compositionally zoned, two-layer magma reservoir. Linear trends define subparallel arrays of amphibole 10Ti 2Mg/(Mg+Fe2+) composition—each trend is likely related to a particular layer EXPLANATION in a two-layer magma reservoir—which suggest successive Cores, tuff of Mt. Jefferson DRS-92-20 Rims, tuff of Mt. Jefferson DRS-92-20 amphibole crystallization from either Ca- and Mg-rich magma, Cores, tuff of Mt. Jefferson DRS-85-199 or crystallization from more fractionated, Ti-rich (more evolved) Rims, tuff of Mt. Jefferson DRS-85-199 Cores, tuff of Mt. Jefferson DRS-85-197 magma. Compositions of these amphiboles vary widely within Rims, tuff of Mt. Jefferson DRS-85-197

2+ Ca Figure 16. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe ) showing relative cation abundances in hornblende of three samples, southern Toquima Range, Nye County, Nevada. (Samples DRS-92-20, DRS-85-199, and DRS-85-197; unit Tmj of Shawe, 1995)

10Ti 2Mg/(Mg+Fe2+) EXPLANATION Tuff of Mt. Jefferson DRS-91-169 Tuff of Mt. Jefferson DRS-92-20 Tuff of Mt. Jefferson DRS-85-199 Tuff of Mt. Jefferson DRS-85-197 Tuff of Mt. Jefferson DRS-85-204 10Ti 2Mg/(Mg+Fe2+) Tuff of Mt. Jefferson DRS-85-203 EXPLANATION Tuff of Mt. Jefferson DRS-85-44 Cores, tuff of Mt. Jefferson DRS-92-20 Figure 15. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing Rims, tuff of Mt. Jefferson DRS-92-20 relative cation abundances in hornblende of seven samples, Figure 17. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing southern Toquima Range, Nye County, Nevada. (Samples relative cation abundances in hornblende of one sample, DRS-91-169, DRS-92-20, DRS-85-199, DRS-85-197, DRS-85-204, southern Toquima Range, Nevada. (Sample DRS-92-20; unit Tmj DRS-85-203, and DRS-85-44; unit Tmj of Shawe, 1995) of Shawe, 1995) Phenocryst Compositions as Determined by Electron Microprobe 29 the edenite and pargasite/magnesiohastingsite fields (fig. 18). plagioclase feldspar in sample DRS-91-168 is relatively The well-defined compositional trend of amphibole from sample enriched in albite, whereas sample DRS-85-44 plagioclase is DRS-92-20 (fig. 18) suggests progressive top-down eruption relatively enriched in anorthite. from a vertically zoned magma reservoir (more evolved compositions near its top and less evolved compositions at Isom-Type Ash-Flow Tuff (Unit Ti) depth); the lack of amphibole compositional discontinuities suggests eruption from a single, continuously zoned reservoir. We determined compositions of phenocrysts in three Compositions of amphibole in other samples appear to indicate samples of Isom-type tuffs (Ti); however, compositions of mixing of lower and upper magma composition layers during biotite were not determined in any of these samples. Analyses eruption of the associated magmas. of amphiboles in samples DRS-84-34 and DRS-87-52 (fig. 21) Pyroxene compositions (fig. 19) in six analyzed samples indicate compositional trends strikingly similar to those of of tuff of Mount Jefferson (Tmj) (DRS-85-44, DRS-85-203, the tuff of Mount Jefferson (Tmj) (generally two subparallel DRS-92-20, DRS-85-199, DRS-85-197, and DRS-91-169) trends, as in fig. 12). The two trends suggest derivation from define a restricted composition range in the augite field. a magma reservoir with two compositional layers. Like Inasmuch as compositions of biotite and amphibole suggest amphiboles in the tuff of Mount Jefferson, amphiboles in the crystallization from a zoned magma reservoir, the single augite Isom-type tuff cluster near the boundary of the edenite and the composition field suggests that augite likely crystallized early pargasite/magnesiohastingsite composition fields (fig. 22). in only one (presumably the lower, less fractionated) zone of a Samples DRS-87-52, DRS-87-59, and DRS-84-34 two-layer magma reservoir. all contain hypersthene but only DRS-84-34 also contains We determined compositions of feldspar phenocrysts in augite (fig. 23). Sample DRS-87-52 was collected from the two samples of the tuff of Mount Jefferson (Tmj) (fig. 20). upper part of the formation. The stratigraphic positions of One sample, DRS-85-44, was collected approximately sample DRS-87-59 and DRS-84-34, as deduced from sample 700 m below the top of the tuff, whereas the other sample, locations on the geologic map, are from the upper and lower DRS-91-168, was collected about 100 m below its top. parts, respectively. Compositions of hypersthene in samples Although the composition fields of feldspars from the two DRS-87-52 and DRS-87-59 (from the upper part of the samples overlap, sanidine in sample DRS-91-168 is potassium formation) are similar, whereas hypersthene compositions in rich relative to sanidine in sample DRS-85-44, and the sample DRS-84-34 are more enriched in enstatite (more mafic)

0.85 Edenite Pargasite/magnesiohastingsite 0.80

0.75

) 0.70 2+

0.65

Mg/(Mg+Fe 0.60

0.55

0.50 Ferroedenite Ferropargasite/Hastingsite

0.45 7.5 7.3 7.1 6.9 6.7 6.5 6.3 6.1 5.9 5.7 5.5 Si in formula

EXPLANATION Tuff of Mt. Jefferson DRS-91-169 Tuff of Mt. Jefferson DRS-85-204 Tuff of Mt. Jefferson DRS-92-20 Tuff of Mt. Jefferson DRS-85-203 Tuff of Mt. Jefferson DRS-85-199 Tuff of Mt. Jefferson DRS-85-44 Tuff of Mt. Jefferson DRS-85-197 Figure 18. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of seven samples, southern Toquima Range, Nye County, Nevada. (Samples DRS-91-169, DRS-92-20, DRS-85-199, DRS-85-197, DRS-85-204, DRS-85-203, and DRS-85-44; unit Tmj of Shawe, 1995) 30 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

WO than are the other two samples. The presence of abundant hypersthene in the Isom-type ash-flow tuff Ti( ) and ferrosilite- molecule-enriched augite preclude an affinity with the tuff of Mount Jefferson (Tmj). Plagioclase feldspar in sample DRS-87-52 is relatively enriched in anorthite, whereas that in sample DRS-84-34 is enriched in albite (fig. 24), which suggests that the tuff was erupted top down from a normally zoned reservoir. Sanidine phenocrysts in Isom-type tuff samples have generally Diopside Hedenbergite overlapping, indistinguishable compositions. Most compositions of phenocrysts in Isom-type tuff samples are dissimilar to those in the volcanic rocks erupted Augite from the southern Toquima Range, which confirms derivation of Isom-type ash-flow tuffs from outside the area.

Bates Mountain Tuff (Part of Unit Ty) Hypersthene Three ash-flow tuff units grouped in the unit designated EN FS EXPLANATION on plate 1 as unit Ty are the Bates Mountain Tuff, the tuff of Tuff of Mt. Jefferson DRS-91-169 Clipper Gap, and the tuff of Pipe Organ Spring, all younger Tuff of Mt. Jefferson DRS-85-199, DRS-85-197, DRS-92-20 than the Isom-type ash-flow tuff (see earlier section, Bates Tuff of Mt. Jefferson DRS-85-203, DRS-85-44 Mountain Tuff, Tuff of Clipper Gap, and Tuff of Pipe Organ Figure 19. Ternary diagram showing proportions of wollastonite, Spring, that describes these units). We determined compositions enstatite, and ferrosilite clinopyroxene in six samples, southern of phenocrysts in three samples (DRS-91-3, DRS-91-6, and Toquima Range, Nye County, Nevada. (Samples DRS-91-169, DRS-91-25) of the Bates Mountain Tuff, the oldest of these DRS-85-199, DRS-85-197, DRS-92-20, DRS-85-203, and DRS-85-44; three tuffs. Relative stratigraphic positions of these samples are unit Tmj of Shawe, 1995; WO, wollastonite; EN, enstatite; FS, ferrosilite) uncertain, so constraining the petrogenetic history of the Bates

An Ca

Ab Or 10Ti 2Mg/(Mg+Fe2+) EXPLANATION EXPLANATION Cores, tuff of Mt. Jefferson DRS-91-168 Cores, Isom-type tuff, upper DRS-87-52 Rims, tuff of Mt. Jefferson DRS-91-168 Rims, Isom-type tuff, upper DRS-87-52 Cores, tuff of Mt. Jefferson DRS-85-44 Cores, Isom-type tuff, DRS-84-34 Rims, tuff of Mt. Jefferson DRS-85-44 Rims, Isom-type tuff, DRS-84-34 Figure 20. Ternary diagram showing molecular end-member Figure 21. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing proportions of albite, anorthite, and orthoclase feldspars in relative cation abundances in hornblende of two samples southern two samples, southern Toquima Range, Nye County, Nevada. Toquima Range, Nye County, Nevada. (Samples DRS-87-52 and (Samples DRS-91-168, and DRS-85-44; unit Tmj of Shawe, 1995; DRS-84-34; unit Ti of Shawe, 1999b) Ab, albite; An, anorthite; Or, orthoclase) Phenocryst Compositions as Determined by Electron Microprobe 31

0.85 Edenite Pargasite/magnesiohastingsite

0.80

0.75

0.70 ) 2+

0.65

Mg/(Mg+Fe 0.60

0.55

0.50 Ferroedenite Ferropargasite/Hastingsite

0.45 7.5 7.3 7.1 6.9 6.7 6.5 6.3 6.1 5.9 5.7 5.5 Si in formula EXPLANATION Cores, Isom-type tuff, upper DRS-87-52 Rims, Isom-type tuff, upper DRS-87-52 Cores, Isom-type tuff, DRS-84-34 Rims, Isom-type tuff, DRS-84-34 Figure 22. Diagram showing relative cation abundances of Si and Mg/(Mg+Fe2+) in hornblende of two samples, southern Toquima Range, Nye County, Nevada. (Samples DRS-87-52 and DRS-84-34; unit Ti of Shawe, 1999b)

WO An

Diopside Hedenbergite

Augite

Hypersthene

EN FS Ab Or EXPLANATION EXPLANATION Cores, Isom-type tuff, upper DRS-87-52 Rims, Isom-type tuff, upper DRS-87-52 Cores, Isom-type tuff, upper DRS-87-52 Cores, Isom-type tuff, DRS-84-34 Rims, Isom-type tuff, upper DRS-87-52 Rims, Isom-type tuff, DRS-84-34 Cores, Isom-type tuff, lower DRS-84-34 Cores, Isom-type tuff, DRS-87-59 Rims, Isom-type tuff, lower DRS-84-34 Rims, Isom-type tuff, DRS-87-59 Figure 24. Ternary diagram showing molecular end-member Figure 23. Ternary diagram showing proportions of wollastonite, proportions of albite, anorthite, and orthoclase feldspars in two enstatite, and ferrosilite in pyroxenes in three samples, southern samples, southern Toquima Range, Nye County, Nevada. (Samples Toquima Range, Nye County, Nevada. (Samples DRS-87-52, DRS-87-52 and DRS-87-34; unit Ti of Shawe,1999b; Ab, albite; DRS-84-34, and DRS-87-59, unit Ti of Shawe, 1999b; WO, An, anorthite; Or, orthoclase) wollastonite; EN, enstatite; FS, ferrosilite) 32 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Mountain Tuff is not possible. Establishing the petrogenesis Ca of the Bates Mountain is further stymied because the map area includes at least three eruptive units of unknown relative stratigraphic position. Nevertheless, amphibole and feldspar composition variations indicate that their source magmas had distinct compositions. The composition of amphibole in sample DRS-91-3 (fig. 25) has slightly elevated abundances of Ca and values for 2Mg/(Mg+Fe2+) relative to Ti abundances as compared with amphibole from sample DRS-91-6 (fig. 25). Amphibole in sample DRS-91-3 is ferroedenite, whereas that in sample DRS-91-6 is pargasite/magnesiohastingsite (fig. 26). Plagioclase in sample DRS-91-3 contains approximately equal amounts of anorthite and albite components (fig. 27), whereas that in sample DRS-91-25 contains a distinctly greater albite component, which suggests a distinctly more evolved source magma. Likewise, sanidine in sample DRS-91-25 is distinctly enriched in the orthoclase component, also indicative of slightly more evolved source magma. Consequently, magma represented by sample DRS-91-3 was less evolved than that of either sample 10Ti 2Mg/(Mg+Fe2+) DRS-91-6 or sample DRS-91-25. EXPLANATION Core, Bates Mountain Tuff DRS-91-6 Intermediate, Bates Mountain Tuff DRS-91-6 Rim, Bates Mountain Tuff DRS-91-6 Petrogenesis of the Tuff of Mount Core, Bates Mountain Tuff DRS-91-3 Jefferson (Unit Tmj), and Its Possible Figure 25. Ternary diagram of Ca–10Ti–2Mg/(Mg+Fe2+) showing relative cation abundances in hornblende of two samples, southern Relation to Other Tuffs Toquima Range, Nye County, Nevada. (Samples DRS-91-6 and DRS-91-3; unit Ty of Shawe, 1999b) A transitional zone a few hundred meters thick, near the top of the principal member of the tuff of Mount Jefferson but each sample includes two distinct biotite composition (Tmj) and just below overlying volcaniclastic rocks of Little fields that vary slightly in relative MgO and Fe2++MnO ratios. Tlt Table Mountain ( ), contains several features that help Analyses of hornblende phenocrysts in sample DRS-91-169 characterize the late evolution of the source magma reservoir. (fig. 13, no data for DRS-91-168) also define two distinct The zone is exposed on the southwest side of Corcoran Canyon compositional fields characterized by significantly different about 2 km east of the summit of Little Table Mountain (Shawe, MgO/Fe2++MnO ratios. Analyses of pyroxene phenocrysts Hardyman, and Byers, 2000) (fig. 1). A dark-gray crystal-poor in samples of the tuff of Mount Jefferson (Tmj) indicate its vitrophyre crops out between underlying crystal-poor welded crystallization only in the lower, less evolved layer of a zoned ash-flow tuff and overlying crystal-rich welded ash-flow tuff; magma reservoir (fig. 19). this tuff grades upward through interlayered tuff, tuff breccia, and sandstone-conglomerate into sandstone and siltstone at the • 26.70±0.03 Ma (40Ar/39Ar on ash-flow tuff; this report) base of volcaniclastic rocks of Little Table Mountain (Tlt). A • 26.80±0.03 Ma (40Ar/39Ar on dark-gray vitrophyric 40 39 Ar/ Ar date on a sample of the dark-gray vitrophyric layer layer; this report) is 26.80±0.03 Ma (sample R9, Shawe, Hardyman, and Byers, 2000; sample DRS-91-98, Tmj, this report), and a 40Ar/39Ar Boden (1989) used compositions of glass (fiamme) date on a sample of ash-flow tuff collected about 50 m higher and biotite to suggest that the ash-flow tuff units erupted in the section is 26.70±0.03 Ma (sample DRS-91-169, Tmj, from his Toquima caldera complex reflect eruption from pl. 1; also, sample R8, Shawe, Hardyman, and Byers, 2000; a compositionally zoned magma reservoir. Our results sample DRS-91-171, Tmj, this report). As indicated by Shawe, corroborate Boden’s (1989) conclusion. However, we conclude Hardyman, and Byers (2000), tuff immediately underlying that the compositional similarity of phenocrysts in the tuff of the vitrophyre has a PI of 3, the vitrophyre a PI of 4, and Mount Jefferson and in Boden’s tuff of Trail Canyon (Boden, immediately overlying tuff a PI of 1. Higher tuff layers have 1986, 1992) indicates that the two are parts of a single ash- PIs of 3, 4, and 5, but the geologic context of these samples is flow tuff (tuff of Mount Jefferson (Tmj)), as is consistent with such that stratigraphic positions are uncertain. The sample of 40Ar/39Ar age dates and petrographic data. the tuff underlying the vitrophyre (DRS-91-168), and a sample Compositions of biotite, hornblende, and clinopyroxene of the vitrophyre (DRS-91-169), collected about 15 m apart in a sample (DRS-92-1) of vitrophyre from the megabreccia stratigraphically, have similar PIs (3 and 4, respectively) and of Jefferson Canyon (Tjc) are distinct relative to those from have virtually indistinguishable biotite compositions (fig. 12), samples of the tuff of Mount Jefferson (see appendixes 3, 6, Interpretative Summary of Phenocryst Compositions 33

0.85 Edenite Pargasite/magnesiohastingsite

0.80

0.75

0.70 ) 2+

0.65

Mg/(Mg+Fe 0.60

0.55

0.50 Ferroedenite Ferropargasite/Hastingsite

0.45 7.5 7.3 7.1 6.9 6.7 6.5 6.3 6.1 5.9 5.7 5.5 Si in formula EXPLANATION Core, Bates Mountain Tuff DRS-91-6 Intermediate, Bates Mountain Tuff DRS-91-6 Rim, Bates Mountain Tuff DRS-91-6 Core, Bates Mountain Tuff DRS-91-3 Figure 26. Diagram showing relative cation abundances of Si and Mg/(Mg + Fe2+) in hornblende of two samples, southern Toquima Range, Nye County, Nevada. (Samples DRS-91-6 and DRS-91-3; unit Ty of Shawe, 1999b)

An and 8 and figs. 3, 12–17, and 19). The distinction suggests that the megabreccia is not related to the volcanic rocks of the Mount Jefferson caldera, as Shawe (1995) previously suggested. Provided that the vitrophyre is not a clast in the megabreccia of Jefferson Canyon, the distinction makes more probable the conclusions of Boden (1986, 1992), Henry and others (1996), and Henry (1997) and, supported by age data, that the megabreccia is related to a caldera now largely buried beneath the alluvium of Big Smoky Valley. Interpretative Summary of Phenocryst Compositions Compositions of biotite, amphibole, and augite in parts of both the tuffs of Corcoran Canyon and Ryecroft Canyon are remarkably similar to those in parts of the tuff of Mount Jefferson. In samples of these tuffs for which compositions of Ab Or augite and feldspars were also determined, compositions of EXPLANATION Cores, Bates Mountain Tuff DRS-91-25 these phenocrysts are particularly similar as well. Phenocryst Rims, Bates Mountain Tuff DRS-91-25 composition similarities among the tuffs of Corcoran Canyon, Cores, Bates Mountain Tuff DRS-91-3 Ryecroft Canyon, and Mount Jefferson suggest a common Rims, Bates Mountain Tuff DRS-91-3 origin and petrogenesis of the magmas that produced Figure 27. Ternary diagram showing molecular end-member these welded ash-flow tuffs. The apparent age span of the proportions of albite, anorthite, and orthoclase in feldspars in petrogenetically related calderas that produced ash-flow two samples, southern Toquima Range, Nye County, Nevada. tuffs extends from about 27.17 to 26.61 Ma. Consequently, (Samples DRS-91-25 and DRS-91-3; unit Ty of Shawe, 1999b; development of this segment of the southern Toquima caldera Ab, albite; An, anorthite; Or, orthoclase) complex transpired during about 560,000 years. 34 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Compositions of phenocrysts from the younger Isom- References type and Bates Mountain Tuff indicate that the petrogenesis of these units is unrelated to that of the tuffs that had sources within our map area; consequently they are derived from Best, M.G., Christiansen, E.H., Deino, A.L., Gromme, C.S., sources external to the Toquima Range. McKee, E.H., and Noble, D.C., 1989, Excursion 3A— Eocene through Miocene volcanism in the Great Basin of the western United States, in Chapin, C.E., and Zidek, J., The Southern Toquima Range Caldera eds., Field excursions to volcanic terranes in the western United States, volume II—Cascades and Intermountain Complex, a Summary West: New Mexico Bureau of Mines and Mineral Resources Memoir 47, p. 91–133. Nine calderas characterize the southern Toquima Range as a major center of volcanic activity during the late Eocene, Boden, D.R., 1986, Eruptive history and structural develop- Oligocene, and earliest Miocene (about 34–24 million years ago; ment of the Toquima caldera complex, central Nevada: see plate 1, list of map units). In succession (oldest to youngest) Geological Society of America Bulletin, v. 97, p. 61–74. these are the inferred Dry Canyon, the Northumberland, the Boden, D.R., 1989, Evidence for step-function zoning of poorly defined Corcoran Canyon, the Big Ten Peak, the inferred magma and eruptive dynamics, Toquima caldera complex, Ryecroft Canyon, the Moores Creek, the Mount Jefferson, the Nevada: Journal of Volcanology and Geothermal Research, Round Mountain (which is mostly covered by alluvium in the Big Smoky Valley), and the Manhattan calderas. The ash-flow v. 37, p. 39–57. tuffs erupted from these calderas are calc-alkalic trachydacites Boden, D.R., 1992, Geologic map of the Toquima caldera to rhyolites. Plugs and dikes are associated with all of the complex, central Nevada: Nevada Bureau of Mines and calderas, have compositions similar to those of the associated Geology Map 98, scale 1:48,000. tuffs, and were emplaced along or near caldera margins. Eruptive Brem, G.F., John, D.A., Nash, J.T., Poole, F.G., and Snyder, megabreccias at or near caldera margins, or forming outflow or D.B., 1991, Mineral resources of the Arc Dome Wilderness interlayered units, characterize several of the calderas. Collapse megabreccias are probable components of some of the calderas Recommendation Area, Nye County, Nevada: U.S. Geologi- and may be associated with eruptive megabreccia deposits. cal Survey Bulletin 1961, 21 p. Regional northwest-southeast-striking faults likely Brem, G.F., and Snyder, D.B., 1983, Lithology and gravity controlled development of some of the calderas; the southwest characteristics of the southern Peavine volcanic center, structural margins of the Manhattan, Mount Jefferson, and Big Toiyabe Range, Nevada: Geological Society of America Ten Peak calderas seem to have been particularly influenced by Abstracts with Program, v. 15, no. 5, p. 280. these faults. Tertiary igneous activity prior to development of the Dalrymple, G.B., Alexander, B.C., Lanphere, M.A., and 40 39 southern Toquima Range caldera complex included late Eocene Kraker, G.P, 1981, Irradiation of samples for Ar/ Ar dat- (about 36 million years ago) emplacement of a few plugs and ing using the Geological Survey TRIGA reactor: U.S. Geo- many dikes composed of granodiorite and andesite to rhyolite. logical Survey Professional Paper 1176, 55 p. Volcanic rocks in the area derived from outside sources and Dodge, F.C.W., Smith, V.C., and Mays, R.E., 1969, Biotites having ages similar to those of the younger caldera rocks were from granitic rocks of the central Sierra Nevada batholith, emplaced during the Oligocene (about 26–25 million years ago). California: Journal of Petrology, v. 10, p. 250–271. Ferguson, H.G., 1921, The Round Mountain district, Nevada: Acknowledgments U.S. Geological Survey Bulletin 725–I, p. 383–406. Ferguson, H.G., 1924, Geology and ore deposits of the Greg Meeker of the U.S. Geological Survey provided Manhattan district, Nevada: U.S. Geological Survey valuable suggestions to Byers on operation of the microprobe Bulletin 723, 163 p. and results of the microprobe analyses. Shawe acknowledges Ferguson, H.G., and Cathcart, S.H., 1954, Geology of the the U.S. Geological Survey Pecora Fellowship and Round Mountain quadrangle, Nevada: U.S. Geological Bradley Scholarship programs for its support. Similarly, Survey Quadrangle Map GQ–40, scale 1:125,000. U.S. Geological Survey Mineral Resources Program support for work in the Toquima Range has been critical to the success Fleck, R.J., Sutter, J.H., and Elliot, D.H., 1977, Interpretation of these activities. Constructive reviews by R.D. Taylor of discordant 40Ar/39Ar age-spectra of Mesozoic tholeiites and Harald Drewes helped clarify our presentation and are from Antarctica: Geochimica et Cosmochimica Acta, v. 41, much appreciated. p. 15–32. References 35

Henry, C.D., 1997, Recent progress in understanding caldera Renne, P.R., Swisher, C.C., Deino, A.L., Karner, D.B., Owens, development and mineralization of the southern Toquima T.L., and DePaolo, D.J., 1998, Intercalibration of standards, Range near Round Mountain, Nevada: Fall 1997 Field Trip absolute ages and uncertainties in 40Ar/39Ar dating: Chemi- Guidebook, Geological Society of Nevada Special Publica- cal Geology, v. 145, p. 117–152. tion 26, p. 241–246. Roddick, J.C., 1983, High precision intercalibration of Henry, C.D., Castor, S.B., and Elson, H.B., 1996, Geology and 40Ar/39Ar standards: Geochimica et Cosmochimica Acta, 40Ar/39Ar geochronology of volcanism and mineralization at v. 47, p. 887–898. Round Mountain, Nevada, in Conyer, A.R., and Fahey, P.L., Samson, S.D., and Alexander, E.G., 1987, Calibration of eds., Geology and ore deposits of the American Cordillera, interlaboratory 40Ar/39Ar dating standard MMhb-1: Isotope Reno/Sparks, Nevada, April 1995, Symposium Proceed- Geoscience, v. 66, p. 27–34. ings: Geological Society of Nevada publication 95-1, v. 1, Shawe, D.R., 1981, Geologic map of the Round Mountain p. 283–307. quadrangle, Nye County, Nevada: U.S. Geological Survey John, D.A., 1992, Stratigraphy, regional distribution, and Open-File Report 81–515, scale 1:24,000. reconnaissance geochemistry of Oligocene and Miocene Shawe, D.R., 1987, Stratigraphic nomenclature of volcanic volcanic rocks in the Paradise Range and northern Pactolus rocks near Manhattan, southern Toquima Range, Nye Hills, Nye County, Nevada: U.S. Geological Survey Bul- County, Nevada: U.S. Geological Survey Bulletin 1775–A, letin 1974, 67 p. p. A1–A8. Keith, W.J., 1987, Preliminary geologic map of the Big Ten Shawe, D.R., 1988, Complex history of precious metal depos- Peak quadrangle, Nye County, Nevada: U.S. Geological its, southern Toquima Range, Nevada, in Schafer, R.W., Survey Open-File Report 87–7, scale 1:62,500. Cooper, J.J., and Vikre, P.G., eds., Bulk Mineable Precious Metal Deposits of the Western United States, Symposium Keith, W.J., 1993, Megabreccia of the Big Ten Peak Caldera, Proceedings, Reno, Nevada, 1987: Geological Society of Nye County, Nevada: U.S. Geological Survey Open-File Nevada publication 87-1, p. 333–373. Report 93–21, 16 p. Shawe, D.R., 1995, Geologic map of the Round Mountain Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., quadrangle, Nye County, Nevada: U.S. Geological Survey Gilbert, M.C., Grice, J.D., Hawthorne, F.C., Kato, Akira, Geologic Quadrangle Map GQ–1756, scale 1:24,000. Kisch, H.J., Krivovichev, V.G., Linthout, Kees, Laird, Shawe, D.R., 1998, Geologic map of the Belmont West Jo, Mandarino, J.A., Maresch, W.V., Nickel, E.H., Rock, quadrangle, Nye County, Nevada: U.S. Geological Survey N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, Geologic Quadrangle Map GQ–1801, scale 1:24,000. N.C.N., Ungaretti, Luciano, Whitaker, E.J.W., and Youzhi, Shawe, D.R., 1999a, Geologic map of the Manhattan quadran- Guo, 1997, Nomenclature of amphiboles—Report of the gle, Nye County, Nevada: U.S. Geological Survey Geologic Subcommittee on Amphiboles of the International Miner- Quadrangle Map GQ–1775, scale 1:24,000. alogical Association, Commission on New Minerals and Mineral Names: American Mineralogist, v. 82, no. 9–10, Shawe, D.R., 1999b, Geologic map of the Jefferson quadrangle, Nye County, Nevada: U.S. Geological Survey Geologic p. 1019–1037. Investigations Series Map I–2670, scale 1:24,000. Le Bas, M.J., Le Maitre, R.W., Streckeisen, A., and Zanet- Shawe, D.R., 2001, Map of steep structure in part of the tin, B.A., 1986, A chemical classification of volcanic rocks southern Toquima Range and adjacent areas, Nye County, based on the total alkali-silica diagram: Journal of Petrol- Nevada: U.S. Geological Survey Miscellaneous Field Stud- ogy, v. 27, p. 745–750. ies Map MF–2327–B, scale 1:48,000. Marvin, R.F., Mehnert, H.H., and McKee, E.H., 1973, A Shawe, D.R., 2002, Geologic map of part of the southern summary of radiometric ages of Tertiary volcanic rocks in Toquima Range and adjacent areas, Nye County, Nevada: Nevada and eastern California; Part 3; southeastern Nevada: U.S. Geological Survey Miscellaneous Field Studies Isochron/West, no. 6, p. 1–30. Map MF–2327–A, scale 1:48,000. McKee, T.H., 1974, Northumberland caldera and Northumber- Shawe, D.R., 2003a, Geologic map of part of the southern land Tuff, in Guidebook to the geology of four Tertiary vol- Toquima Range and adjacent areas, Nye County, Nevada: canic centers in central Nevada: Nevada Bureau of Mines U.S. Geological Survey Miscellaneous Field Studies and Geology Report 19, p. 35–41. Map MF–2327A, scale 1:48,000. McKee, T.H., and John, D.A., 1987, Sample location map and Shawe, D.R., 2003b, Geochemistry, geochronology, mineral- potassium-argon ages and data for Cenozoic igneous rocks ogy, and geology suggest sources of and controls on mineral in the Tonopah 1 degree by 2 degree quadrangle, central systems in the southern Toquima Range, Nye County, Nevada: U.S. Geological Survey Miscellaneous Field Stud- Nevada: U.S. Geological Survey Miscellaneous Field Stud- ies Map MF–1877–I, scale 1:250,000. ies Map MF–2327–C, scale 1:48,000, with pamphlet. 36 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada

Shawe, D.R., and Byers, F.M., Jr., 1999, Geologic map of the Shawe, D.R., and Snyder, D.B., 1988, Ash-flow eruptive Belmont East quadrangle, Nye County, Nevada: U.S. Geo- megabreccias of the Manhattan and Mount Jefferson calde- logical Survey Geologic Investigations Series Map I–2675, ras, Nye County, Nevada: U.S. Geological Survey Profes- scale 1:24,000. sional Paper 1471, 28 p. Silberman, M.L., and McKee, E.H., 1972, A summary of Shawe, D.R., Hardyman, R.F., and Byers, F.M., Jr., 2000, radiometric age determinations on Tertiary volcanic rocks Geologic map of the Corcoran Canyon quadrangle, Nye from Nevada and eastern California; part II, western County, Nevada: U.S. Geological Survey Geologic Investi- Nevada: Isochron/West, no. 4, p. 7–28. gations Series Map I–2680, scale 1:24,000. Silberman, M.L., Shawe, D.R., Koski, R.A., and Goddard, Shawe, D.R., Kucks, R.P., and T.G. Hildenbrand, 2004, B.B., 1975, K-Ar ages of mineralization at Round Moun- Geologic insights and comments on mineral potential based tain and Manhattan, Nye County, Nevada: Isochron/West, on analyses of geophysical data of the southern Toquima no. 13, p. 1–2. Range, Nye County, Nevada: U.S. Geological Survey Mis- Snee, L.W., 2002, Argon thermochronology of mineral cellaneous Field Studies Map I–2327–D, scale 1:48,000. deposits—A review of analytical methods, formulations, Shawe, D.R., Marvin, R.F., Andriessen, P.A.M., Mehnert, and selected applications: U.S. Geological Survey Bulle- tin 2194, 39 p. H.H., and Merritt, V.M., 1986, Ages of igneous and hydro- thermal events in the Round Mountain and Manhattan gold Steiger, R.H., and Jäger, E., 1977, Subcommission on geochronology: Convention on the use of decay constants in districts, Nye County, Nevada: Economic Geology, v. 81, geo- and cosmochronology: Earth and Planetary Science p. 388–407. Letters, v. 36, p. 359–362. Shawe, D.R., Naeser, C.W., Marvin, R.F., and Mehnert, H.H., U.S. Geological Survey Geologic Names Committee, 2010, 1987, New radiometric ages of igneous and mineralized Divisions of geologic time—Major chronostratigraphic rocks, southern Toquima Range, Nye County, Nevada: Iso- and geochronologic units. U.S. Geological Survey Fact chron/West, no. 50, p. 3–7. Sheet 2010–3059, 2 p. Appendixes

Appendix 1 39

R Ar 1.61 0.07 0.11 0.06 0.09 0.07 0.05 0.04 0.04 0.04 0.04 0.12 0.45 1.28 0.09 0.04 0.04 0.06 0.1 0.05 0.04 0.04 0.15 40 Error ArT, ArT, 39 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

ArT, ArT, 40 age 16.9 30.1 27.8 27.2 26.9 27.1 27 27 27 27.1 27.2 27.3 18.7 21.3 28.7 28.1 27.6 27.2 27.4 27.1 27.1 27 26.9 Apparent Ar 39 0.2 1.2 2.8 7.5 6 7.9 11.5 12.8 14.2 18.5 12.7 4.6 0.9 0.6 2.3 7 4.8 6.1 9.7 22.2 23.8 17.2 5.3 % Ar) are shown in volts. All Ar) are shown in volts. (irradiation-produced 36 K

Ar 40 Rad yield 7.79 57.11 56.53 91.5 94.35 95.48 96.53 97.09 96.93 97.89 97.28 95.38 17.74 37.03 38.57 86 90.8 91.08 92.57 91.83 91.23 90.83 88.02 (initial I Ar), 40 Ar 36 K/Ca Ar, and Ar, 2.74194 7.22684 12.28788 15.79152 21.41945 26.6244 33.84287 36.85065 37.95027 42.01598 44.3146 34.519 7.5512 19.08846 30.47288 60.97098 63.94158 52.31667 85.85455 48.4772 39.8709 47.22191 10.21529 37 (radiogenic R F Ar ) for each temperature step is directly calculated from 40 1.37 2.45 2.27 2.21 2.19 2.2 2.19 2.2 2.2 2.2 2.22 2.22 1.51 1.71 2.31 2.27 2.23 2.19 2.21 2.18 2.18 2.17 2.16 K Ar 39 I / R Ar 36 Ar 40 0.00084 0.00075 0.00162 0.00049 0.00024 0.00025 0.00026 0.00024 0.00028 0.00023 0.00022 0.00015 0.00164 0.00049 0.00223 0.00067 0.00027 0.00033 0.00043 0.00108 0.00125 0.00095 0.00039 Ar± 36 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00002 0.00001 0 0 0.00001 0.00002 0.00002 0.00001 0.00001 0.00002 (irradiation produced Ca-derived Ar ratio of aliquots of atmospheric argon pipetted from a fixed pipette on the extractionAr ratio of aliquots atmospheric argon T Ca 36 Ar Ar 36 37 Ar/ 40 0.00084 0.00076 0.00162 0.00049 0.00025 0.00025 0.00027 0.00024 0.00029 0.00024 0.00022 0.00015 0.00164 0.00049 0.00224 0.00067 0.00028 0.00033 0.00044 0.0011 0.00128 0.00097 0.0004 Ar), 38 Ca Ar) listed in the table. Fractions included plateau or prefe rred dates (weighted-mean date) are shown Ar 36 37 0.00279 0.00842 0.01122 0.02324 0.01378 0.01447 0.01661 0.01704 0.0183 0.02159 0.01397 0.00658 0.00459 0.0013 0.00295 0.00448 0.00291 0.0045 0.0044 0.01776 0.02316 0.01415 0.01995 (initial I Cl moles argon per volt signal. The “F” value ( per volt signal. moles argon Ar Ar 38 –12 36 ). Ca 0.00028 0.00059 0.00018 0.0001 0.00009 0 0 0.00015 0.00011 0.00001 0 0.00003 0.00165 0.00164 0.00927 0.026 0.01691 0.02119 0.03387 0.07835 0.08519 0.05868 0.01809 10 × Ar 37 / K Ar) and Ar± 40 Ar 39 39 0.00002 0.00009 0.00004 0.00031 0.00054 0.00086 0.00051 0.00042 0 0.00109 0.00063 0.00041 0.00001 0.00001 0.00019 0.00033 0.00038 0.00031 0.00082 0.00162 0.00162 0.0008 0.00012 (irradiation-produced Cl-derived Cl (initial I K Ar Ar Ar 38 was degassed in a vacuum furnace prior to irradiation release extraneous argon. 39 40 4 0.0153 0.1217 0.27574 0.73399 0.59032 0.77051 1.12426 1.25587 1.38898 1.81425 1.23815 0.45427 0.06932 0.04963 0.17979 0.5463 0.37214 0.47085 0.75552 1.72191 1.84682 1.33638 0.40759 k SO Ar), k 2 39 Ar Ar 39 I 39 Ar ; the K 40 4 0.26882 0.52073 1.1023 1.76546 1.3632 1.76878 2.54328 2.83362 3.13681 4.06909 2.80939 1.05363 0.58801 0.229 1.0754 1.43612 0.90897 1.12995 1.79249 4.07824 4.39539 3.18285 0.99841 SO Wt.=66 mg Wt.=57.8 mg 2 K and K 2 Ar 40 0.00014 0.00114 0.00258 0.00686 0.00552 0.0072 0.01051 0.01174 0.01299 0.01696 0.01158 0.00425 0.00065 0.00046 0.00168 0.00511 0.00348 0.0044 0.00706 0.0161 0.01727 0.0125 0.00381 R Ar 40 (irradiation-produced K-derived K 0.02094 0.29801 0.62463 1.6216 1.29136 1.69563 2.46525 2.76261 3.05318 4.00001 2.74422 1.00901 0.10444 0.08497 0.41545 1.23946 0.82847 1.03318 1.66593 3.75967 4.02585 2.90237 0.88219 SANIDINE BIOTITE Ar 39 Ar), 40 Ar± on ratios for this experiment are available in Snee (2002). Apparent ages of each fraction include the error in J value Ar were determined using the method of Roddick (1983). Producti on ratios for this experiment are available in Snee (2002). 40 36 0.0002 0.00052 0.0004 0.0006 0.00016 0.00153 0.00069 0.00075 0.00077 0.00152 0.00208 0.0009 0.0004 0.00038 0.00144 0.00157 0.00076 0.0005 0.00168 0.00345 0.00407 0.00055 0.00024 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada. Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 (initial I Ar/ ArT) were measured on a MAP 215 mass spectrometer on a Faraday collector in volts to five decimal places. The corrected abundances for 215 mass spectrometer on a Faraday collector in volts to five decimal places. ArT) were measured on a MAP Ar 40 36 T 40 as shown in the table. K/Ca is calculated from expression K/Ca=0.5( K Ar

40 Ar Ar), 39 RH-TP-571/1/DD57 0.26897 0.52187 1.10488 1.77232 1.36872 1.77598 2.55379 2.84537 3.1498 4.08606 2.82096 1.05788 RH-TP-571/2/DD57 0.58866 0.22946 1.07708 1.44123 0.91245 1.13435 1.79955 4.09434 4.41266 3.19535 1.00222 40 Ar, which are produced during irradiation, are radioactive and their abundances were corrected for radioactive decay. Abundances of interfering isotopes from K and Ca were calculated reactor production which are produced during irradiation, radioactive and their abundances were corrected for decay. Ar, 39 ArT, and ArT, Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 37 36 36 850 950 900 1150 1100 1050 1200 1250 1300 1350 1400 1450 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ ArT, ArT, Ar and TEMP ºC Sample: 40 J-value and its error: 0.006865±0.1% Plateau date: 27.00±0.06 Ma on steps: 5 to 9 containing 52.4% Total-gas date: 27.12±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.00693±0.1% containing 68.5% Plateau date: 27.02±0.07 Ma on steps: 8 to 11 date: 27.1±0.07 Ma Total-gas Appendix 1. Mountains, Nevada. Mineral separates were packaged in aluminum foil and stacked quartz glass vials Toquima [Ninety-nine-percent-pure mineral separates were prepared from rock samples collected throughout the Colo., in irradiation packages DD54, reactor in Denver, TRIGA with monitor minerals placed between every second sample and at the top bottom of each vial. Samples were irradiated in th e U.S. Geological Survey’s DD57, and DD58. isotopic total abundances ( Argon Irradiated samples were heated in temperature steps a double -vacuum furnace, and the released gasses cleaned according to procedures described Snee (2002). may be converted to moles using 1.160 Voltages errors on measured voltages are cited at 1 sigma. divided by All isotopic abundances have been corrected for mass discrimination. Mass discrimination was determined by calculating the including atmospheric argon. line; the ratio during this experiment was 298.9, which cor rected to 295.5 account for mass discrimination. Final isoto pic abundances were corrected all interfering isotopes of a rgon 37 ratios determined by irradiating and analyzing pure CaF Corrections for Cl-derived 1987), and K-Ar age of Alexander, The standards for this experiment were hornblende MMhb-1 (Samson and from several standards. (0.1 percent), which was calculated from the reproducibility of splits argon Apparent ages were calculated using decay Laboratory against MMhb-1 (Snee, 2002). Argon +523.1+2.6 Ma (age reevaluated by Renne and others, 1998) sanidine FCT 1 with a measured age of 28.03 in the Denver All apparent age errors are cited at 1 sigma. Uncertainties in the calculations for of individual fractions were calculated using equations Dalrymple and others (1981). constants of Steiger and Jäger (1977). Isochron diagrams were produced for all samples and may be derived by using in bold type. Plateaus were determined according to the method of Fleck and others (1977)] 38 K-derived 40 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada –3.93 18.48 2.22 0.16 0.06 0.06 0.04 0.04 0.04 0.16 11.55 1.96 2.35 2.35 0.51 0.22 0.04 0.04 0.04 0.15 0.25 0.5 0.34 0.15 0.04 0.04 0.04 0.04 0.04 0.05 0.04 0.04 0.21 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 12.8 24.9 27.8 27 26.8 26.9 26.9 26.8 26.4 22.4 36.7 31.9 22.1 28.4 27.3 26.7 26.7 26.7 27 27.2 26.2 27.9 27 26.8 26.7 26.9 26.9 26.9 26.8 26.9 26.9 26.5 –14.8 Apparent Ar 0.1 0.3 0.6 4.3 3.7 0.1 1.1 0.7 0.8 2.9 8.1 8 0.6 1.3 3.4 6.6 7.3 8.7 2.3 39 11.1 10.8 16.2 21.5 25.5 17.7 20.1 18.8 26.4 13 12.8 12.7 18.4 14.8 %

2.2 1.27 9.03 14.1 16.4 57.2 81.2 85.9 85.9 81.1 80.9 80.8 21.07 16.84 39.05 56.97 77.56 80.35 78.93 70.98 58.82 60.3 44.38 82.11 94.55 94.81 96.76 97.56 97.91 97.66 98.08 97.26 91.27 Rad yield K/Ca 4.20874 5.41367 0.19532 0.72234 0.37166 0.18284 0.11134 0.07471 0.0693 0.07309 0.08039 0.07949 0.08049 10.05785 12.32338 67.71082 68.1024 34.77108 22.95439 31.12696 27.11364 29.21752 34.9272 41.72194 39.33343 46.2528 49.98668 51.46593 21 101.17538 130.25743 130.98941 120.94018 F 0.69 0.19 2.14 2.19 2.1 2.08 2.08 2.08 2.08 2.1 1.72 2.83 2.45 1.69 2.18 2.1 2.05 2.05 2.05 2.08 2.09 2.01 2.14 2.07 2.05 2.05 2.06 2.06 2.06 2.06 2.06 2.06 2.03 I Ar 36 0.00091 0.00092 0.00183 0.002 0.0015 0.00157 0.00208 0.00356 0.0024 0.00052 0.00117 0.00258 0.00055 0.00054 0.00079 0.00104 0.00096 0.00076 0.00116 0.00089 0.00095 0.00026 0.00118 0.00053 0.00026 0.00026 0.00018 0.00017 0.00016 0.00018 0.0002 0.00025 0.00015 Ar± 36 0.00001 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0 0 0 0 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.00091 0.00092 0.00183 0.00201 0.00151 0.00159 0.0021 0.00358 0.00242 0.00053 0.00117 0.00258 0.00056 0.00056 0.00088 0.00142 0.00197 0.00165 0.00227 0.00145 0.00129 0.00026 0.00118 0.00054 0.00026 0.00027 0.00019 0.00017 0.00016 0.00018 0.00021 0.00026 0.00015 Ca Ar 37 0.00103 0.00121 0.00201 0.00268 0.00459 0.00538 0.00708 0.00911 0.01084 0.02919 0.00663 0.01853 0.02392 0.05226 0.3082 1.30516 3.48899 3.10588 3.95383 1.97256 1.19907 0.00083 0.00285 0.00575 0.01276 0.01301 0.01298 0.0139 0.01702 0.0143 0.01914 0.01497 0.0058 Cl Ar 38 0.00025 0.00054 0.00177 0.01586 0.03902 0.05662 0.07632 0.09305 0.05826 0.01257 0.00015 0.0005 0.00137 0.00252 0.01559 0.06712 0.17509 0.14076 0.11319 0.06234 0.03725 0.00015 0.00011 0 0 0 0 0 0 0 0 0 0 Ar± 39 0.00001 0.00001 0.00002 0.00048 0.00072 0.00138 0.00135 0.00175 0.00027 0.00016 0.00003 0.00002 0 0.00005 0.00001 0.0001 0.00005 0.00035 0.00284 0.00017 0.00013 0.00008 0.00009 0.0004 0.00051 0.00073 0.00065 0.00116 0.00097 0.00057 0.00087 0.00143 0.00014 K Ar 39 0.00867 0.02434 0.04954 0.36293 0.92879 1.40157 1.85481 2.20353 1.47646 0.31605 0.00259 0.02677 0.01778 0.01911 0.06863 0.19503 0.48354 0.454 0.63567 0.31359 0.19303 0.05772 0.13084 0.35796 0.69194 0.76024 0.90671 1.15987 1.33891 1.32283 1.91349 1.54089 0.2436 k k k Ar Ar Ar 39 I 39 39 Ar 40 0.27543 0.31671 0.64575 1.39269 2.39549 3.38527 4.47309 5.63919 3.78349 0.81917 0.34949 0.83734 0.2069 0.19203 0.38332 0.71714 1.27658 1.15528 1.6468 0.91604 0.68359 0.1917 0.62897 0.89889 1.49576 1.63429 1.92422 2.43888 2.80921 2.77462 4.00172 3.25261 0.5404 Wt.=60.2 mg Wt.=190 mg Wt.=68.4 mg K Ar 40 0.00008 0.00022 0.00046 0.00339 0.00868 0.0131 0.01734 0.0206 0.0138 0.00295 0.00002 0.00025 0.00017 0.00018 0.00064 0.00182 0.00452 0.00424 0.00594 0.00293 0.0018 0.00054 0.00122 0.00335 0.00647 0.00711 0.00848 0.01084 0.01252 0.01237 0.01789 0.01441 0.00228 R Ar 40 0.00594 0.00461 0.10605 0.79534 1.95324 2.9199 3.85797 4.58835 3.0734 0.66433 0.00445 0.07567 0.04363 0.03238 0.14993 0.40959 0.99358 0.93163 1.30457 0.65228 0.40314 0.11591 0.27965 0.74085 1.42037 1.55617 1.87006 2.39 2.76277 2.72191 3.94224 3.17749 0.49532 BIOTITE HORNBLENDE SANIDINE Ar± 40 0.00023 0.00021 0.00038 0.00142 0.00218 0.00257 0.00296 0.00547 0.00181 0.00035 0.00006 0.00027 0.0005 0.00006 0.00073 0.00014 0.00042 0.00069 0.00908 0.00012 0.00024 0.00019 0.00027 0.00128 0.00056 0.00148 0.00197 0.00194 0.00201 0.00094 0.00166 0.00282 0.00034 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.27551 0.31693 0.64621 1.39608 2.40417 3.39837 4.49043 5.65979 3.79729 0.82212 0.34952 0.83759 0.20707 0.19221 0.38396 0.71897 1.2811 1.15953 1.65274 0.91897 0.6854 0.19224 0.63019 0.90223 1.50223 1.6414 1.93269 2.44973 2.82173 2.78698 4.01961 3.26702 0.54268 RH-TP-583/6/DD57 RH-TP-583/7/DD57 RH-TP-583/8/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 900 1100 1100 1000 1200 1300 1350 1400 1450 1600 1050 1200 1275 1325 1350 1375 1400 1450 1500 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007237±0.1% Plateau date: 26.86±0.05 Ma on steps: 6 to 9 containing 80.3% date: 26.81±0.16 Ma Total-gas Sample: 40 J-value and its error: 0.00726±0.1% Plateau date: 26.69±0.04 Ma on steps: 7 to 9 containing 65.3% date: 26.98±0.16 Ma Total-gas Sample: 40 J-value and its error: 0.00728±0.1% containing 78.5% Plateau date: 26.87±0.04 Ma on steps: 6 to 11 date: 26.85±0.05 Ma Total-gas Appendix 1. Appendix 1 41 0.08 0.15 0.14 0.04 0.08 0.08 0.09 0.04 0.05 0.04 0.06 0.08 0.25 0.28 0.11 0.06 0.04 0.11 0.08 0.05 0.04 0.04 0.04 0.74 0.04 0.12 0.04 0.07 0.04 0.04 0.05 0.04 0.04 0.04 0.04 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 29.9 28.7 27.4 27.2 27.1 27.3 27.3 27.6 27.6 28 29 30.3 23.82 26.6 27.89 27.52 27.08 27.02 26.98 27.06 26.93 26.98 27.23 26.1 27.3 27.1 27 26.9 26.9 26.8 26.8 26.8 26.9 27.1 27.2 Apparent Ar 39 0.3 1.3 3.9 8.3 7.7 16.3 9.4 13.6 15 13.5 8.6 2.1 1.12 1.38 3.13 8.75 7.27 7.95 10.33 13.41 20.71 19.92 6.02 0.5 1.6 3.2 8.5 8.3 7.2 9 10.4 14.2 20.2 13.4 3.7 %

Rad yield 8.45 28.84 71.15 91.1 93.21 95.85 95.84 96.16 96.41 97.04 95.57 85.36 39.97 64.5 48.1 82.52 90.48 91.86 91.12 89.51 87.22 86.96 83.63 27.53 60.58 72.03 95.01 96.47 95.63 96.8 97.11 97.52 97.61 97.66 95.19 K/Ca 3.30361 5.25039 5.00678 5.92733 7.17784 8.7036 11.10452 14.30211 18.7403 22.80198 18.69793 6.85133 19.94402 33.51587 41.48271 89.51448 92.00413 119.75902 83.65873 30.26596 28.428 58.24729 9.11483 19.94268 13.06987 15.91168 24.35015 31.3462 40.57666 43.59695 45.2998 47.74176 46.5862 44.63032 36.01877 F 2.32 2.24 2.13 2.11 2.1 2.12 2.12 2.14 2.14 2.18 2.26 2.36 1.83 2.05 2.15 2.12 2.08 2.08 2.08 2.08 2.07 2.08 2.1 2.01 2.11 2.09 2.08 2.08 2.08 2.07 2.07 2.07 2.08 2.09 2.1 I Ar 36 0.00249 0.00254 0.00115 0.00057 0.00039 0.00047 0.00027 0.00036 0.00037 0.00027 0.00029 0.00028 0.00096 0.00048 0.00225 0.0012 0.00047 0.00043 0.00062 0.00098 0.0019 0.00187 0.00075 0.00112 0.00094 0.00114 0.00037 0.00024 0.00027 0.00023 0.00024 0.00027 0.00037 0.00024 0.00016 Ar± 36 0 0.00001 0.00001 0 0.00001 0.00002 0.00002 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0 0.00002 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00002 0 0.00001 0.00001 0 0 0 0 T Ar 36 0.00249 0.00254 0.00116 0.00059 0.0004 0.00049 0.00028 0.00037 0.00038 0.00028 0.00029 0.00029 0.00096 0.00048 0.00225 0.00121 0.00048 0.00044 0.00063 0.001 0.00193 0.00189 0.00076 0.00112 0.00094 0.00114 0.00038 0.00025 0.00027 0.00024 0.00024 0.00028 0.00038 0.00025 0.00016 Ca Ar 37 0.00443 0.01296 0.03983 0.07231 0.05547 0.09622 0.04358 0.04884 0.04122 0.03035 0.02372 0.01547 0.00259 0.00189 0.00347 0.00449 0.00363 0.00305 0.00567 0.02036 0.03347 0.01571 0.03035 0.00157 0.0078 0.01319 0.02269 0.01723 0.01148 0.01346 0.01491 0.01942 0.02819 0.01949 0.00666 Cl Ar 38 0.00055 0.00048 0.00014 0.00003 0.00004 0.00008 0.00007 0.0001 0.00011 0.00007 0.00003 0.00002 0.00326 0.00435 0.01174 0.03249 0.0258 0.02798 0.03652 0.04912 0.07762 0.06813 0.02035 0.00021 0.00003 0.00009 0.00006 0.00015 0 0.00008 0.00003 0.00001 0 0 0 Ar± 39 0.00003 0.00009 0.00044 0.00105 0.00063 0.00232 0.00099 0.00119 0.00153 0.00105 0.00124 0.0001 0.0001 0.00012 0.00028 0.00075 0.00031 0.00059 0.0005 0.00127 0.00133 0.00075 0.0021 0.00001 0.00013 0.00023 0.00089 0.00041 0.00058 0.00093 0.00033 0.00072 0.0008 0.00122 0.00003 K Ar 39 k k k 0.02927 0.13609 0.39884 0.85721 0.79631 1.67492 0.96787 1.39703 1.54495 1.38408 0.88703 0.21198 0.10331 0.12669 0.28789 0.80384 0.66795 0.73053 0.94869 1.23243 1.90297 1.83013 0.55327 0.06262 0.20389 0.41975 1.10501 1.08019 0.93164 1.17363 1.35084 1.85429 2.62653 1.73969 0.47977 Ar Ar Ar 39 39 39 I Ar 40 0.80449 1.05369 1.19034 1.97848 1.79037 3.69043 2.13671 3.10282 3.42095 3.09558 2.08485 0.58302 0.47258 0.40098 1.28279 2.05676 1.53284 1.64767 2.1533 2.85664 4.50575 4.35442 1.3816 0.45704 0.70824 1.21399 2.41167 2.31885 2.01348 2.49993 2.86894 3.92307 5.56199 3.70743 1.05288 Wt.=63.7 mg Wt.=63.7 mg Wt.=73.8 mg K Ar 40 0.00027 0.00127 0.00373 0.00801 0.00745 0.01566 0.00905 0.01306 0.01445 0.01294 0.00829 0.00198 0.00097 0.00118 0.00269 0.00752 0.00625 0.00683 0.00887 0.01152 0.01779 0.01711 0.00517 0.00059 0.00191 0.00392 0.01033 0.0101 0.00871 0.01097 0.01263 0.01734 0.02456 0.01627 0.00449 R Ar 40 0.18927 0.2594 0.61826 1.70346 1.39257 1.51974 1.97015 2.56738 3.94546 3.80131 1.15971 0.12599 0.4302 0.87723 2.30107 2.24667 1.93372 2.43062 2.79825 3.8428 5.45295 3.63657 1.00646 0.06802 0.30425 0.84954 1.80979 1.67583 3.55237 2.05639 2.99635 3.31223 3.01665 2.00039 0.49938 BIOTITE SANIDINE SANIDINE Ar± 40 0.00113 0.0011 0.00116 0.00213 0.00071 0.00045 0.00201 0.00284 0.00172 0.00259 0.00166 0.00033 0.00059 0.00046 0.00113 0.00201 0.00127 0.00108 0.00119 0.00176 0.00055 0.00055 0.0052 0.00045 0.00047 0.00078 0.00125 0.00075 0.00176 0.00222 0.00073 0.0006 0.00235 0.00096 0.00012 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.80476 1.05496 1.19407 1.9865 1.79782 3.70609 2.14576 3.11588 3.43539 3.10852 2.09314 0.585 0.47355 0.40217 1.28548 2.06427 1.53909 1.6545 2.16217 2.86816 4.52354 4.37153 1.38677 0.45763 0.71014 1.21792 2.422 2.32895 2.02219 2.51091 2.88157 3.94041 5.58655 3.72369 1.05737 RH-TP-590/10/DD57 RH-TP-616/11/DD57 RH-TP-590/9/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 850 950 900 900 1150 1100 1100 1050 1200 1250 1300 1350 1400 1450 1550 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.007181±0.1% date: 27.22±0.07 Ma on steps: 4 to 7 containing 41.8% Preferred date: 27.67±0.06 Ma Total-gas 40 J-value and its error: 0.007255±0.1% Plateau date: 26.99±0.06 Ma on steps: 6 to 10 containing 72.32% date: 27.04±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.007231±0.1% Plateau date: 26.85±0.04 Ma on steps: 5 to 10 containing 69.3% date: 26.92±0.05 Ma Total-gas Appendix 1. 42 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 4.64 1.97 0.05 0.04 0.07 0.08 0.04 0.04 0.04 0.04 0.05 0.29 1.19 0.88 0.65 1.93 0.99 0.17 0.24 0.25 0.2 0.07 0.11 0.07 0.14 2.12 1.26 0.05 0.08 0.09 0.04 0.04 0.04 0.04 0.06 0.04 0.08 0.09 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 12.2 28.5 28.9 28 27.6 27.1 27.2 27.1 27.1 27.1 27.1 23.3 26.2 32.6 32.5 29.8 30.4 28.4 27 26.8 26.8 26.8 26.7 26.8 26.8 51.5 28.2 28.4 26.9 26.8 26.8 26.8 26.8 26.9 27 27.1 27.3 26.8 Apparent Ar 0.1 0.4 0.9 7.2 8.8 5.9 8.4 2.3 2.5 1.6 1 0.9 0.9 2.6 5.5 0.1 0.6 2.6 7.5 6.2 8.6 5.6 0.9 39 11.2 10.4 15.7 20.9 21.4 14.4 12.9 12.6 12.9 18.8 10.8 12.1 15.2 16.1 13.7 %

1.65 7.77 Rad yield 11.41 17.93 57.94 84.32 84.53 86.48 84.27 82.69 81.67 77.23 13.58 14.23 25.49 26.39 32.31 44.42 57.36 70.03 78.08 80.03 81.22 79.54 79.84 15.97 44.75 54.8 93.29 94.52 96.36 96.9 97.59 97.87 98.16 96.95 96.18 83.57 K/Ca 6.62626 4.02941 3.79866 1.70488 1.69507 1.11909 1.05212 0.85522 0.72537 0.34415 0.11522 0.08037 0.07741 0.08449 0.09204 0.08295 0.07453 5.11806 7.25622 9.04922 8.4028 11.55012 51.60974 69.42925 78.66622 80.47504 25.65373 30.38807 61.32564 10.49549 12.24745 14.94088 17.80155 21.92016 24.65969 34.76097 34.99226 27.70071 F 0.97 2.28 2.31 2.23 2.2 2.16 2.17 2.16 2.16 2.16 2.16 1.84 2.07 2.58 2.57 2.36 2.4 2.24 2.13 2.12 2.11 2.11 2.11 2.12 2.11 4.05 2.2 2.22 2.1 2.1 2.09 2.09 2.1 2.1 2.11 2.12 2.13 2.1 I Ar 36 0.00257 0.00338 0.00304 0.00388 0.00118 0.00077 0.00115 0.00207 0.0031 0.00342 0.00177 0.00268 0.00392 0.00247 0.00072 0.00058 0.00047 0.00072 0.00087 0.001 0.00083 0.00067 0.0006 0.00069 0.00098 0.00053 0.00064 0.00178 0.0004 0.00026 0.00023 0.00024 0.0002 0.00021 0.00018 0.0003 0.00016 0.00014 Ar± 36 0.00002 0.00002 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0 0.00001 0.00001 0.00002 0.00001 0 0.00001 0.00001 0 0.00001 0.00002 0.00002 0.00001 0.00001 0.00001 0.00002 0 0.00002 0 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00002 0.00001 0.00001 0 T Ar 36 0.00257 0.00338 0.00304 0.00389 0.00119 0.00077 0.00117 0.0021 0.00313 0.00344 0.00179 0.00268 0.00392 0.00247 0.00072 0.00058 0.00048 0.00075 0.00107 0.00158 0.00161 0.00131 0.00116 0.00133 0.00203 0.00053 0.00064 0.00178 0.00041 0.00027 0.00024 0.00025 0.0002 0.00022 0.00019 0.0003 0.00016 0.00014 Ca Ar 37 0.00099 0.00459 0.0112 0.00688 0.00629 0.00373 0.00641 0.03028 0.03404 0.01732 0.03611 0.01989 0.0213 0.02095 0.01343 0.01523 0.01908 0.11036 0.70602 2.04451 2.72577 2.24996 2.00426 2.28923 3.70381 0.00072 0.00482 0.01595 0.03991 0.02839 0.03239 0.03409 0.031 0.03463 0.02598 0.02196 0.01131 0.00607 Cl Ar 38 0.00051 0.0016 0.00396 0.02656 0.02899 0.01856 0.03215 0.05018 0.06975 0.06416 0.02586 0.00332 0.00393 0.00267 0.00162 0.00188 0.00249 0.00911 0.04027 0.10849 0.13958 0.09875 0.05834 0.08878 0.168 0.00022 0.00048 0.00027 0.00011 0.00016 0.00003 0.00011 0 0.00016 0 0 0 0.00002 Ar± 39 0.00004 0.00004 0.00006 0.00002 0.00098 0.00063 0.00097 0.00124 0.00266 0.00107 0.00151 0.00006 0.00008 0.00005 0.00002 0.00001 0.00002 0.00002 0.00005 0.00004 0.00024 0.00031 0.00032 0.00033 0.00044 0.00001 0.00002 0.00008 0.00067 0.00054 0.00052 0.00105 0.00119 0.00044 0.00152 0.0012 0.00049 0.00004 K Ar 39 0.01312 0.03699 0.08509 0.71015 0.87342 0.58685 1.03169 1.55359 2.06882 2.12432 0.83415 0.06782 0.07221 0.04689 0.02826 0.02605 0.02768 0.07596 0.16269 0.32862 0.42203 0.38021 0.36893 0.37978 0.5521 0.00737 0.06995 0.28867 0.83775 0.69541 0.96787 1.21371 1.35905 1.70793 1.80618 1.53686 0.62659 0.10201 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.771 1.08275 1.09381 2.7324 2.27419 1.49559 2.58513 3.97358 5.38645 5.60339 2.32533 0.91572 1.30655 0.84949 0.28464 0.23245 0.20526 0.38261 0.60331 0.99006 1.139 1.0001 0.95444 1.00684 1.45664 0.18693 0.34318 1.16586 1.87578 1.53491 2.09434 2.60619 2.90763 3.65676 3.86238 3.33856 1.38379 0.25498 Wt.=75.3 mg Wt.=217.2 mg Wt.=75.2 mg K Ar 40 0.00012 0.00035 0.0008 0.00664 0.00817 0.00549 0.00965 0.01453 0.01934 0.01986 0.0078 0.00063 0.00068 0.00044 0.00026 0.00024 0.00026 0.00071 0.00152 0.00307 0.00395 0.00355 0.00345 0.00355 0.00516 0.00007 0.00065 0.0027 0.00783 0.0065 0.00905 0.01135 0.01271 0.01597 0.01689 0.01437 0.00586 0.00095 R Ar 40 0.0127 0.08416 0.19629 1.58714 1.9244 1.26893 2.24388 3.36059 4.46978 4.59258 1.8019 0.12448 0.14914 0.12098 0.07262 0.0614 0.0664 0.17026 0.34692 0.69553 0.89247 0.80319 0.77797 0.80362 1.16707 0.02987 0.15388 0.64032 1.75724 1.45702 2.02674 2.53651 2.84988 3.59458 3.808 3.25073 1.33658 0.21388 BIOTITE HORNBLENDE SANIDINE Ar± 40 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 0.00018 0.0012 0.00196 0.00121 0.00042 0.00019 0.0015 0.00172 0.00604 0.00296 0.00267 0.00094 0.00118 0.00041 0.00006 0.0002 0.00003 0.00008 0.00026 0.00028 0.0006 0.00069 0.00064 0.00109 0.00014 0.00009 0.00026 0.00053 0.00024 0.00121 0.00061 0.00204 0.00223 0.00079 0.00079 0.00221 0.00108 0.00009 39 Ar/ T 40 Ar

40 0.77113 1.08309 1.0946 2.73904 2.28236 1.50108 2.59478 3.98811 5.40579 5.62325 2.33313 0.91635 1.30722 0.84993 0.2849 0.2327 0.20552 0.38332 0.60483 0.99314 1.14295 1.00365 0.95789 1.01039 1.4618 0.187 0.34383 1.16856 1.88362 1.54141 2.10339 2.61754 2.92033 3.67273 3.87926 3.35293 1.38965 0.25593 RH-TP-644/3/DD57 RH-TP-644/4/DD57 RH-TP-644/5/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 900 800 900 1100 1150 1100 1100 1000 1200 1250 1300 1350 1375 1400 1425 1450 1500 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1000 1200 1250 1300 1350 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: 40 J-value and its error: 0.006996±0.1% containing 82.7% Plateau date: 27.12±0.04 Ma on steps: 6 to 11 date: 27.21±0.07 Ma Total-gas Sample: 40 J-value and its error: 0.007076±0.1% Plateau date: 26.80±0.14 Ma on steps: 8 to 14 containing 88.2% date: 26.95±0.21 Ma Total-gas Sample: 40 J-value and its error: 0.007148±0.1% Plateau date: 26.83±0.07 Ma on steps: 4 to 9 containing 60.4% date: 26.99±0.06 Ma Total-gas Appendix 1. Appendix 1 43 0.83 0.96 2.32 0.04 0.07 0.08 0.05 0.04 0.07 0.04 0.1 0.7 0.53 0.04 0.07 0.04 0.08 0.15 0.04 0.04 0.04 0.05 1.74 0.39 0.04 0.05 0.04 0.04 0.06 0.07 0.04 0.04 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

8.3 16.7 26.4 27.9 27.5 27.5 27.2 27.2 27 26.9 26.9 27.8 28.3 27.6 27 26.8 26.9 26.9 26.9 26.9 27.1 27 10.8 17.7 23.7 24.9 25 24.9 24.9 24.9 24.9 24.9 age Apparent Ar 0.4 0.6 0.7 4.8 8.4 4.7 6.1 0.3 1.3 3.1 6.8 6.8 9 0.8 0.8 2.4 7.8 39 12.8 21 28.1 12.5 10.9 12.6 15.3 18.7 15.3 15.3 12.6 12.5 12.9 13.3 21.6 %

4.69 Rad 21.43 34.19 49.91 87.39 89.6 89.67 90.14 90.21 90.74 90.44 15.58 31.56 67.44 81.29 86.01 92.06 94.67 96.16 96.36 97.11 96.08 15.38 28.96 26.68 74.64 87.39 86.97 82.43 78.22 78.17 80.8 yield K/Ca 5.88477 7.68475 6.52941 7.39037 9.45173 11.90384 47.22762 68.10482 67.83026 72.03211 42.12108 18.20453 36.01024 16.47962 30.5208 39.20378 44.84421 46.28818 45.50933 52.76363 53.81168 55.26167 49.90024 14.75 22.57547 22.53947 65.49734 60.77154 14.38178 26.87951 133.02885 236.9256 F 0.63 1.28 2.03 2.15 2.11 2.11 2.09 2.09 2.07 2.07 2.07 2.13 2.17 2.11 2.07 2.05 2.06 2.06 2.06 2.06 2.07 2.07 0.82 1.35 1.81 1.9 1.91 1.9 1.9 1.9 1.9 1.9 I Ar 36 0.00131 0.00072 0.00073 0.00268 0.00065 0.00029 0.00037 0.00074 0.00119 0.00149 0.00069 0.00108 0.00219 0.00116 0.00114 0.0008 0.00055 0.00042 0.00033 0.00038 0.00036 0.00042 0.00078 0.00053 0.00259 0.00106 0.00087 0.00074 0.00106 0.00144 0.00149 0.00205 Ar± 36 0.00001 0.00001 0.00003 0 0.00001 0.00001 0.00001 0 0.00003 0.00001 0.00002 0.00001 0.00002 0 0.00001 0.00001 0.00002 0 0 0.00001 0.00001 0.00001 0.00002 0 0 0 0 0 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.00131 0.00072 0.00073 0.00269 0.00066 0.0003 0.00037 0.00075 0.00122 0.00152 0.00071 0.00108 0.00219 0.00116 0.00115 0.0008 0.00055 0.00043 0.00034 0.00038 0.00036 0.00042 0.00079 0.00053 0.00259 0.00106 0.00088 0.00075 0.00107 0.00146 0.0015 0.00207 Ca Ar 37 0.00256 0.00295 0.00425 0.00391 0.00477 0.00271 0.00327 0.01181 0.04464 0.03027 0.04061 0.00187 0.00417 0.00553 0.00925 0.00812 0.01041 0.01286 0.01284 0.01524 0.01821 0.01649 0.00174 0.00106 0.00342 0.00376 0.00364 0.00168 0.0065 0.0433 0.02931 0.02548 Cl Ar 38 0.0009 0.00175 0.00219 0.01332 0.02151 0.01194 0.01546 0.03346 0.05768 0.07006 0.02967 0.0004 0.00026 0.00007 0.00008 0.00001 0.00002 0.00005 0.00002 0 0.00007 0 0.00105 0.00107 0.00409 0.01245 0.02351 0.01901 0.01875 0.02029 0.02047 0.03254 Ar± 39 0.00001 0.00005 0 0.0004 0.00076 0.00039 0.00022 0.00035 0.00091 0.00031 0.00024 0.00004 0.00006 0.00027 0.00071 0.00072 0.00063 0.00662 0.00004 0.00092 0.00039 0.00092 0.00005 0.00005 0.00006 0.00051 0.00115 0.00094 0.00066 0.00098 0.00066 0.00001 K Ar 39 0.03013 0.04534 0.0555 0.36932 0.64972 0.36764 0.47109 0.9949 1.6253 2.18006 0.96683 0.02764 0.13744 0.33756 0.72527 0.72827 0.96372 1.1705 1.35497 1.64018 2.01263 1.64571 0.05133 0.04786 0.15417 0.49254 0.96845 0.79607 0.79003 0.81852 0.84306 1.36978 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.40559 0.2695 0.32906 1.58459 1.56608 0.86203 1.09357 2.29465 3.71765 4.94477 2.20263 0.37738 0.94452 1.05508 1.83694 1.73305 2.14906 2.53795 2.8919 3.49278 4.27874 3.5276 0.27397 0.22233 1.04401 1.2482 2.10917 1.73268 1.81404 1.98364 2.04234 3.21001 Wt.=57.5 mg Wt.=61.7 mg Wt.=49.5 mg K Ar 40 0.00028 0.00042 0.00052 0.00345 0.00607 0.00344 0.0044 0.0093 0.0152 0.02038 0.00904 0.00026 0.00129 0.00316 0.00678 0.00681 0.00901 0.01094 0.01267 0.01534 0.01882 0.01539 0.00048 0.00045 0.00144 0.00461 0.00905 0.00744 0.00739 0.00765 0.00788 0.01281 R Ar 40 0.01903 0.05785 0.11267 0.79266 1.37393 0.77547 0.98456 2.07681 3.36739 4.5054 2.0002 0.05882 0.29852 0.71364 1.49873 1.49649 1.98675 2.41301 2.79301 3.38045 4.17341 3.40393 0.04222 0.06451 0.27888 0.93506 1.85101 1.51346 1.50136 1.55762 1.60274 2.60405 BIOTITE SANIDINE BIOTITE Ar± 40 0.00003 0.00032 0.00021 0.00184 0.00148 0.00088 0.00066 0.00019 0.00294 0.00055 0.0013 0.00047 0.00038 0.00067 0.00236 0.00159 0.00058 0.00075 0.00035 0.00349 0.00036 0.00102 0.00005 0.00007 0.00094 0.00099 0.00035 0.00127 0.00184 0.0007 0.0018 0.00021 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.40587 0.26992 0.32958 1.58804 1.57215 0.86547 1.09798 2.30395 3.73285 4.96515 2.21167 0.37763 0.9458 1.05824 1.84372 1.73986 2.15807 2.54889 2.90457 3.50811 4.29756 3.54299 0.27445 0.22278 1.04545 1.25281 2.11822 1.74012 1.82143 1.99129 2.05022 3.22282 RH-646/12/DD57 RH-TP-646/13/DD57 RH-TP-659/14/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 800 900 1100 1100 1100 1000 1200 1250 1300 1350 1400 1450 1550 1000 1200 1250 1300 1350 1400 1450 1500 1600 1000 1200 1250 1300 1350 1400 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.00727±0.1% containing 61.5% Plateau date: 26.93±0.07 Ma on steps: 9 to 11 date: 26.96±0.09 Ma Total-gas Sample: 40 J-value and its error: 0.007291±0.1% Plateau date: 26.90±0.07 Ma on steps: 5 to 9 containing 61.3% date: 27±0.07 Ma Total-gas Sample: 40 J-value and its error: 0.007305±0.1% Plateau date: 24.92±0.05 Ma on steps: 4 to 10 containing 96.0% date: 24.7±0.08 Ma Total-gas Appendix 1. 44 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 2 5.55 0.54 1.54 2.14 0.37 0.89 0.31 0.04 0.04 0.12 5.27 0.2 0.07 0.06 0.11 0.15 0.03 0.09 0.04 0.08 0.04 0.11 2.98 1.06 0.23 0.17 0.16 0.08 0.13 0.08 0.11 0.23 0.35 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 28.9 40.9 29 22.7 30.6 13.7 26.6 24.9 24.8 25 25.2 22.2 26.2 25.1 25 25 25 25.2 25.3 26.2 28.1 34.1 46.6 33.05 34.02 30.28 29.64 29.69 29.71 29.67 29.82 29.66 29.5 29.11 Apparent Ar 39 0.8 0.8 1.2 0.8 0.6 0.5 3.1 5.2 0.1 1.3 3.1 7.9 7.3 9.5 3.1 0.42 1.24 5.31 9.29 6.92 1.77 % 11.9 36.9 34.3 15.8 13.2 14 15.4 13.2 12.75 22.14 10.32 13.28 16.57

9.8 5.33 Rad 11.9 11.77 10 15 19.5 23.5 45.9 54.3 74.4 80.4 69.5 41.67 53.71 84.19 91.32 94.17 95.4 95.72 96.91 96.85 96.09 89.26 yield 30.64 54.94 69.73 78.09 84 76.13 80.25 82.65 74.21 43.14 K/Ca 0.57725 0.84719 0.77878 0.37978 0.16036 0.05575 0.06589 0.06851 0.07104 0.07654 0.0694 5.06593 6.31009 0.32754 0.10927 0.10138 0.10419 0.10256 0.10371 0.10229 0.09838 0.0996 0.09928 0.0993 12.94361 16.11496 20.38672 26.16696 29.43234 34.20209 40.79054 40.45116 48.37885 30.6197 F 2.21 3.14 2.22 1.73 2.34 1.04 2.03 1.9 1.9 1.91 1.93 1.7 2 1.92 1.9 1.91 1.91 1.92 1.93 2 2.15 2.61 3.58 2.65 2.73 2.43 2.38 2.38 2.38 2.38 2.39 2.38 2.37 2.34 I Ar 36 0.00111 0.00091 0.00129 0.00041 0.0003 0.00032 0.0005 0.00056 0.00161 0.00106 0.00089 0.0004 0.00111 0.00162 0.00087 0.0004 0.00033 0.00035 0.00029 0.00024 0.00029 0.0004 0.00041 0.00177 0.00068 0.00093 0.00084 0.00074 0.00087 0.00067 0.00068 0.00072 0.0005 0.00048 Ar± 36 0.00001 0.00002 0.00001 0.00001 0.00001 0 0.00001 0.00001 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00003 0 0.00002 0.00001 0.00003 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 T Ar 36 0.00112 0.00091 0.0013 0.00041 0.00031 0.00035 0.00063 0.00077 0.00306 0.00231 0.00152 0.0004 0.00111 0.00163 0.00087 0.0004 0.00033 0.00035 0.00029 0.00024 0.0003 0.00041 0.00041 0.00178 0.00072 0.00113 0.00118 0.00121 0.00167 0.00105 0.00118 0.00134 0.00076 0.00055 Ca Ar 37 0.01424 0.0089 0.01494 0.02221 0.0362 0.08968 0.46804 0.7619 5.20595 4.49257 2.27421 0.00091 0.00932 0.01126 0.02279 0.01664 0.01689 0.02084 0.01623 0.01597 0.01771 0.01267 0.00472 0.01696 0.14807 0.68488 1.16654 1.62694 2.7932 1.31974 1.766 2.17744 0.91164 0.23272 Cl Ar 38 0.00039 0.0002 0.00058 0.00095 0.00099 0.00137 0.01061 0.02027 0.13696 0.10152 0.0509 0.00052 0.00168 0.00108 0.00101 0.00051 0.00061 0.00083 0.00073 0.00046 0.00013 0.00006 0.00003 0.00058 0.00503 0.03011 0.05345 0.07204 0.11124 0.04666 0.06582 0.08105 0.03389 0.00861 Ar± 39 0.00001 0.00002 0.00001 0.00002 0.00002 0.00001 0.00002 0.00007 0.00079 0.00001 0.0002 0 0.00001 0.00045 0.00079 0.00008 0.00064 0.00057 0.00163 0.001 0.00036 0.00083 0.00031 0.00002 0.00005 0.00012 0.00016 0.00034 0.00062 0.00014 0.00028 0.0011 0.00012 0.00005 K Ar 39 0.01644 0.01508 0.02327 0.01687 0.01161 0.01 0.06168 0.10439 0.73961 0.6877 0.31568 0.00922 0.11762 0.29149 0.73452 0.67847 0.88392 1.22674 1.1102 1.30285 1.43278 1.22592 0.28905 0.01111 0.03236 0.13887 0.24309 0.33373 0.57937 0.26998 0.34747 0.43374 0.18102 0.04622 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.36472 0.3156 0.43315 0.1499 0.11545 0.10628 0.27197 0.36432 1.87848 1.62907 0.87201 0.13275 0.5638 1.03845 1.65516 1.41136 1.78287 2.4585 2.233 2.67515 3.16417 3.31905 1.15521 0.55268 0.28837 0.61303 0.82677 1.01495 1.63868 0.84188 1.03272 1.24519 0.57573 0.24982 Wt.=226.4 mg Wt.=59.9 mg Wt.=191.1 mg K Ar 40 0.00015 0.00014 0.00022 0.00016 0.00011 0.00009 0.00058 0.00098 0.00692 0.00643 0.00295 0.00009 0.0011 0.00273 0.00687 0.00634 0.00826 0.01147 0.01038 0.01218 0.0134 0.01146 0.0027 0.0001 0.0003 0.0013 0.00227 0.00312 0.00542 0.00252 0.00325 0.00406 0.00169 0.00043 R Ar 40 0.03629 0.04734 0.05158 0.02918 0.02714 0.01042 0.12516 0.19851 1.40325 1.31542 0.60801 0.01563 0.23541 0.55923 1.39922 1.2946 1.68665 2.35623 2.14731 2.60429 3.07745 3.20014 1.03361 0.02949 0.08845 0.33752 0.57809 0.79497 1.38112 0.64281 0.8314 1.03249 0.42851 0.10796 HORNBLENDE SANIDINE HORNBLENDE Ar± 40 0.00055 0.00041 0.00078 0 0.00007 0.00016 0.00019 0.00018 0.00155 0.00085 0.00003 0.00012 0.00053 0.00145 0.00156 0.00038 0.00194 0.00031 0.00174 0.00197 0.00104 0.00176 0.0004 0.00083 0.00016 0.00018 0.00039 0.00076 0.00077 0.00028 0.00044 0.00141 0.00012 0.00007 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.36487 0.31574 0.43337 0.15006 0.11556 0.10637 0.27254 0.36529 1.88539 1.6355 0.87496 0.13283 0.5649 1.04117 1.66203 1.41771 1.79113 2.46997 2.24338 2.68734 3.17757 3.33051 1.15792 0.55278 0.28868 0.61433 0.82904 1.01807 1.6441 0.84441 1.03596 1.24925 0.57742 0.25026 RH-TP-659/16/57/DD57 RH-TP-659/15/DD57 RH-TP-672/18/57/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 900 1100 1050 1275 1325 1350 1375 1400 1425 1450 1500 1550 1600 1100 1000 1200 1250 1300 1350 1375 1425 1450 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007308±0.1% Plateau date: 24.92±0.18 Ma on steps: 8 to 10 containing 76.4% date: 25.19±0.16 Ma Total-gas Sample: 40 J-value and its error: 0.007313±0.1% Ma on steps: 3 to 8 containing 52.9% Plateau date: 25.21±0.11 date: 27.6±0.08 Ma Total-gas Sample: 40 J-value and its error: 0.006965±0.1% Plateau date: 29.70±0.12 Ma on steps: 4 to 9 containing 84.35% date: 29.77±0.15 Ma Total-gas Appendix 1. Appendix 1 45 2.41 0.34 0.1 0.08 0.09 0.05 0.05 0.05 0.05 0.07 0.06 0.13 1.41 0.05 0.12 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.05 0.79 0.4 0.19 0.06 0.09 0.06 0.04 0.04 0.04 0.04 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 32.66 29.58 30.14 29.78 29.83 29.79 29.77 29.88 29.87 29.99 29.93 29.91 30.7 26.4 26.4 26.6 26.6 26.7 26.8 26.7 26.8 27 27.4 19.8 20.9 24.4 27.3 27.7 27.5 27.4 27.4 27.3 27.3 Apparent Ar 39 0.14 1.02 4.07 7.88 8.87 2.37 0.1 1.4 4.1 7.1 7.7 8.1 0.7 1.4 1.9 6.7 7.6 8.4 11.54 10.99 12.1 13.09 14.22 13.71 % 10.4 10.7 12 16.6 21.8 14.3 15.4 23.2 20.5

Rad yield 21.45 34.73 87.94 94.54 94.37 95.97 96.66 96.69 96.68 97.05 96.99 84.77 14.1 46.1 91.6 95.4 94.9 97.2 97.7 97.7 97.7 97.7 96.2 16.4 24.3 19.5 67.6 71.5 73.8 79.8 82.7 87.1 88.4 K/Ca 1.85251 7.308824 10.9458 15.97587 18.91805 24.13332 31.58107 32.10602 44.16837 43.09777 45.76409 17.76299 16.31633 27.36697 34.7565 35.65922 50.79234 49.40359 52.14763 50.12747 52.80157 49.23711 47.7932 7.269 6.33174 14.5389 32.97471 27.82919 29.98534 40.99958 12.75524 18.57394 5.22872 F 2.58 2.41 2.45 2.43 2.43 2.43 2.42 2.43 2.43 2.44 2.44 2.44 2.45 2.03 2.01 2.02 2.02 2.03 2.04 2.03 2.04 2.05 2.08 1.62 1.69 1.99 2.15 2.19 2.17 2.16 2.16 2.15 2.15 I Ar 36 0.0004 0.00144 0.00042 0.00032 0.00038 0.00032 0.00028 0.00027 0.0003 0.00029 0.00028 0.00032 0.00082 0.00192 0.00041 0.00037 0.00045 0.0003 0.00025 0.00027 0.00039 0.00051 0.00035 0.00135 0.00167 0.00357 0.00159 0.00152 0.00148 0.00178 0.00157 0.00166 0.0013 Ar± 36 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00002 0.00001 0.00001 0 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.0004 0.00144 0.00042 0.00033 0.00038 0.00032 0.00029 0.00027 0.00031 0.00029 0.00029 0.00032 0.00082 0.00192 0.00042 0.00038 0.00045 0.0003 0.00025 0.00028 0.0004 0.00052 0.00035 0.00135 0.00167 0.00357 0.0016 0.00152 0.00149 0.00179 0.00159 0.00169 0.00134 Ca Ar 37 0.00339 0.00646 0.01716 0.02279 0.02166 0.02104 0.0177 0.0166 0.01369 0.01524 0.01384 0.00616 0.00049 0.00436 0.01 0.01702 0.01293 0.01784 0.01751 0.02028 0.02681 0.03762 0.01441 0.00329 0.00734 0.00437 0.00692 0.00925 0.00955 0.0119 0.04104 0.0426 0.13379 Cl Ar 38 0.00033 0.0002 0.00003 0.00018 0.00006 0.00011 0.00008 0.00008 0.00007 0.00003 0.00005 0.00001 0.00019 0.00016 0.00002 0.00008 0.00011 0.00018 0.00031 0.00027 0.00018 0.00029 0.00013 0.00095 0.00196 0.0029 0.01028 0.01157 0.01285 0.02204 0.02402 0.03613 0.03497 Ar± 39 0.00023 0.00002 0.00014 0.00128 0.00118 0.00048 0.0007 0.00064 0.00064 0.00039 0.00046 0.00018 0.00002 0.00022 0.00032 0.00039 0.00061 0.00127 0.00028 0.00013 0.00007 0.00147 0.00065 0.00006 0.00009 0.00009 0.00019 0.00033 0.00036 0.00004 0.00065 0.00088 0.00027 K Ar 39 k k 0.01256 0.09443 0.37566 0.72818 0.81953 1.01553 1.11797 1.06592 1.20933 1.31362 1.26675 0.21884 0.01599 0.23864 0.69513 1.21384 1.31349 1.76272 1.82621 2.03317 2.83122 3.7046 1.3774 0.04783 0.09295 0.12707 0.45637 0.51484 0.57272 0.97579 1.04695 1.5825 1.3991 k Ar Ar Ar 39 39 39 I Ar 40 0.15089 0.65383 1.0451 1.86117 2.10203 2.55695 2.79346 2.67219 3.03095 3.29372 3.17126 0.62676 0.2786 1.04617 1.5153 2.55946 2.78449 3.66375 3.79233 4.21207 5.88494 7.74205 2.97403 0.47358 0.64631 1.298 1.44935 1.57042 1.67713 2.63052 2.72186 3.88735 3.39151 Wt.=59.7 mg Wt.=81.7 mg Wt.=43.9 mg K Ar 40 0.00012 0.00088 0.00351 0.00681 0.00766 0.0095 0.01045 0.00997 0.01131 0.01228 0.01184 0.00205 0.00015 0.00223 0.0065 0.01135 0.01228 0.01648 0.01708 0.01901 0.02647 0.03464 0.01228 0.00045 0.00087 0.00119 0.00427 0.00481 0.00535 0.00912 0.00979 0.0148 0.01308 R Ar 40 0.03239 0.22741 0.92212 1.76599 1.99083 2.46314 2.71019 2.59338 2.94138 3.20853 3.08726 0.53304 0.03921 0.48348 1.39408 2.45082 2.65289 3.57661 3.72037 4.13235 5.77116 7.59204 2.87178 0.0777 0.15698 0.25281 0.98325 1.12597 1.24389 2.10952 2.26098 3.39939 3.01169 SANIDINE SANIDINE BIOTITE Ar± 40 0.00181 0.00039 0.00012 0.00192 0.00149 0.00104 0.00149 0.00105 0.00007 0.00045 0.00057 0.00012 0.00016 0.00077 0.00078 0.00154 0.00161 0.00089 0.00029 0.00284 0.00045 0.00227 0.00143 0.00044 0.00043 0.001 0.00062 0.00108 0.00056 0.00071 0.00143 0.0016 0.00024 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.15101 0.65471 1.04862 1.86798 2.10969 2.56644 2.80392 2.68215 3.04226 3.306 3.1831 0.62881 0.27875 1.0484 1.5218 2.57081 2.79677 3.68023 3.80941 4.23108 5.91141 7.77669 2.98631 0.47403 0.64718 1.29919 1.45362 1.57523 1.68248 2.63964 2.73165 3.90215 3.40459 RH-TP-672/17/DD57 DRS-85-10/43/DD58 DRS-85-27/46/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 900 1100 1000 1200 1250 1300 1350 1400 1500 1100 1000 1200 1250 1300 1350 1400 1450 1500 1600 1100 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.006864±0.1% Plateau date: 29.87±0.07 Ma on steps: 4 to 12 containing 94.78% date: 29.88±0.07 Ma Total-gas Sample: 40 J-value and its error: 0.00736±0.1% date: 26.78±0.05 Ma on steps: 6 to 9 containing 49.7% Preferred date: 26.82±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007103±0.1% Plateau date: 27.36±0.05 Ma on steps: 6 to 10 containing 81.8% date: 27.16±0.06 Ma Total-gas Appendix 1. 46 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 1.78 0.53 0.21 0.11 0.04 0.06 0.05 0.04 0.04 0.04 0.04 0.42 1.25 2.64 3.24 1.13 0.18 0.17 0.15 0.07 0.05 0.08 0.15 0.27 0.06 0.04 0.04 0.04 0.04 0.04 0.04 0.09 0.04 0.13 0.64 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

5.1 age 25.1 26.1 27.5 27.2 26.9 26.9 26.9 26.9 26.9 26.8 16.3 22.4 20.8 22.6 21.5 23.5 24.6 25.2 25.3 25.3 25.4 25.5 22.6 25.1 25.3 25.5 25.4 25.5 25.5 25.5 25.5 25.5 25.6 18.4 Apparent Ar 0.1 1 2.3 5.7 9.2 7.6 39 1.4 1.1 0.6 0.5 1.4 4.6 5.4 2 8 8 3.3 0.5 11.8 11.4 12.9 14.2 18.6 15 13.5 13.8 20.2 19.4 15.4 16.5 10.3 10.1 12.1 12.4 10.2 %

3 Rad 28.4 39.3 82.4 90.5 91.6 92.3 90.8 90.7 89.8 88.1 19.1 10 20.4 22.8 34.9 55 72 84.4 90.7 91.2 88.5 87.4 53.4 75.8 90.7 91.8 93 94.8 95.3 95.3 95 94.1 86.4 26.7 yield K/Ca 1.65957 6.4136 7.73434 1.65465 1.13373 0.56659 0.26806 0.1425 0.09912 0.09037 0.08768 0.08737 0.08792 0.08791 0.08222 7.91802 9.2918 8.25344 11.53242 13.85934 30.07742 55.60594 48.29886 61.7902 62.27936 32.73972 13.27504 16.59093 19.30663 31.54861 39.26324 51.31824 83.80363 54.31993 42.4004 F 0.54 2.06 2.13 2.22 2.19 2.17 2.17 2.17 2.17 2.17 2.17 1.31 1.5 1.66 1.8 1.7 1.84 1.92 1.96 1.97 1.97 1.98 1.99 1.81 2 2.01 2.02 2.02 2.02 2.05 2.03 2.02 2.02 2.03 1.49 I Ar 36 0.00046 0.0016 0.00236 0.00083 0.00063 0.00045 0.0007 0.00093 0.00124 0.0011 0.0012 0.00089 0.00219 0.00044 0.00037 0.00052 0.00082 0.00048 0.00059 0.00047 0.00042 0.00046 0.00055 0.0014 0.00222 0.0007 0.00078 0.00064 0.00053 0.00049 0.0005 0.00049 0.00054 0.00045 0.00081 Ar± 36 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00002 0.00002 0.00002 0 0 0.00001 0.00001 0.00001 0.00001 0.00003 0 0.00001 0.00001 T Ar 36 0.00046 0.0016 0.00236 0.00084 0.00065 0.00046 0.00072 0.00096 0.00127 0.00113 0.00123 0.0009 0.00219 0.00044 0.00038 0.00057 0.00105 0.00078 0.00137 0.00163 0.00151 0.00132 0.00155 0.00141 0.00224 0.00071 0.00079 0.00064 0.00054 0.00049 0.00051 0.00049 0.00054 0.00045 0.00081 Ca Ar 37 0.00235 0.00706 0.01357 0.01884 0.01395 0.00623 0.01228 0.01051 0.01371 0.02092 0.04672 0.01429 0.0209 0.01742 0.03294 0.17028 0.80411 1.05409 2.75031 4.05046 3.86091 3.06632 3.51127 0.01659 0.0561 0.04488 0.04025 0.03395 0.02438 0.01983 0.01568 0.00881 0.01219 0.00502 0.00363 Cl Ar 38 0.00027 0.00122 0.00359 0.02016 0.03668 0.02768 0.04593 0.05469 0.06971 0.05504 0.04716 0.00173 0.00152 0.00099 0.00167 0.00727 0.03073 0.03973 0.09987 0.13644 0.11149 0.07429 0.10159 0.00555 0.02754 0.01231 0.00153 0.00034 0.00031 0.00031 0.00022 0.00016 0.00007 0.00003 0.00008 Ar± 39 0.00004 0 0.00014 0.00024 0.00051 0.00034 0.00075 0.00081 0.00073 0.00041 0.00051 0.00005 0.00002 0.00001 0 0.00005 0.00006 0.0001 0.00021 0.00036 0.00036 0.00023 0.00025 0.00013 0.00068 0.00056 0.00089 0.00072 0.0008 0.00109 0.00099 0.00087 0.00089 0.00014 0.00013 K Ar 39 0.0078 0.09056 0.20991 0.52222 0.83916 0.69285 1.18622 1.29883 1.7077 1.36983 1.24042 0.04729 0.04739 0.01974 0.01766 0.04853 0.15941 0.19052 0.4823 0.70776 0.67887 0.53913 0.57739 0.26272 1.04254 1.03515 1.33557 1.31092 1.53831 1.55718 1.60934 1.47662 1.32432 0.4257 0.05992 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.13911 0.65618 1.1388 1.40146 2.02359 1.63725 2.78204 3.09436 4.06781 3.29605 3.03888 0.32405 0.71211 0.16067 0.13902 0.23588 0.53245 0.5058 1.11663 1.52959 1.46075 1.20097 1.30884 0.88628 2.72984 2.28421 2.92732 2.83007 3.26793 3.32996 3.40651 3.13245 2.83347 0.99688 0.32653 Wt.=207.7 mg Wt.=63.9 mg Wt.=68.5 mg K Ar 40 0.00006 0.00085 0.00196 0.00488 0.00785 0.00648 0.01109 0.01214 0.01597 0.01281 0.0116 0.00044 0.00036 0.00018 0.00017 0.00045 0.00149 0.00178 0.00451 0.00662 0.00635 0.00504 0.0054 0.00246 0.00975 0.00968 0.01249 0.01226 0.01438 0.01475 0.01505 0.01381 0.01238 0.00398 0.00056 R Ar 40 0.00424 0.1867 0.44787 1.15851 1.83931 1.50562 2.57731 2.82129 3.70561 2.97267 2.68697 0.06194 0.07131 0.03283 0.0318 0.08239 0.29381 0.36525 0.94605 1.39313 1.33999 1.06735 1.14817 0.47455 2.08032 2.08015 2.69911 2.64386 3.11223 3.18699 3.25966 2.98972 2.67623 0.86488 0.0892 AMPHIBOLE BIOTITE SANIDINE Ar± 40 0.00006 0.00026 0.00006 0.00066 0.00118 0.00085 0.00171 0.00119 0.00201 0.00151 0.00174 0.0003 0.00058 0.00012 0.00005 0.00015 0.00017 0.00027 0.00048 0.00079 0.00097 0.00056 0.00035 0.00054 0.00196 0.00115 0.00178 0.00164 0.00159 0.00168 0.00132 0.00178 0.00035 0.00043 0.00038 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.13917 0.65703 1.14076 1.40634 2.03144 1.64373 2.79313 3.1065 4.08378 3.30886 3.05048 0.32449 0.71247 0.16085 0.13919 0.23633 0.53394 0.50758 1.12114 1.53621 1.4671 1.20601 1.31424 0.88874 2.73959 2.29389 2.93981 2.84233 3.28231 3.34471 3.42156 3.14626 2.84585 1.00086 0.32709 DRS-85-27/45/DD58 DRS-85-48/49/DD58 DRS-85-27/47/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 900 800 900 1100 1100 1100 1000 1200 1250 1300 1325 1350 1375 1400 1450 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1000 1200 1250 1300 1350 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.006935±0.1% containing 81.8% Plateau date: 26.89±0.05 Ma on steps: 6 to 11 date: 26.89±0.06 Ma Total-gas 40 J-value and its error: 0.007199±0.1% Plateau date: 25.33±0.1 Ma on steps: 8 to 12 containing 85.1% date: 24.96±0.18 Ma Total-gas Sample: 40 J-value and its error: 0.007048±0.1% containing 81.6% Plateau date: 25.49±0.05 Ma on steps: 4 to 11 date: 25.35±0.06 Ma Total-gas Appendix 1. Appendix 1 47 1.39 0.26 0.07 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.05 2.34 0.06 0.04 0.04 0.04 0.08 0.04 0.07 0.04 0.05 0.04 0.04 3.51 0.67 0.06 0.12 0.05 0.11 0.26 0.36 0.24 –5.52 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 25.4 27.2 26.7 26.6 26.8 26.8 26.9 26.8 26.9 26.9 27 19.3 16.9 23.2 25.5 25.9 25.9 25.9 26.2 26.1 26.1 25.9 25.7 15.4 21.6 24.9 24.8 25.2 25.2 25 25.1 25.9 –3 Apparent Ar 39 0.1 2.7 5 9.5 0.1 7.5 4.9 4.4 4.7 6.7 8.9 8.9 0.9 5.3 9 9.3 4.6 0.3 11 10.3 12.1 10 14.5 10.5 12.5 12.9 13.4 13.4 16.1 20.3 20.4 16.3 13.7 %

8 Rad yield 20.4 60.4 94 95.9 96.7 97.3 98.1 97.6 97 96.4 94.4 15.1 25.5 29.2 38.7 53.1 69.4 70.1 65.3 55.4 61.7 82 89.5 22.5 80.1 77.5 91.3 91.7 92.8 91.6 86.2 –2.1 K/Ca 3.87831 5.58811 2.81277 4.25486 5.19758 11.69793 16.72216 40 45.4652 47.97951 59.05404 48.69252 51.63518 31.56754 22.16696 25.99308 32.36773 27.53108 31.08485 33.40985 38.54208 30.29355 22.67181 13.95504 40.16566 23.11409 56.89015 55.20548 39.65098 30.90909 118.76378 100.61658 101.75 F 2.1 2.19 2.14 2.13 2.14 2.15 2.15 1.32 2.15 2.15 2.16 1.5 1.28 1.75 1.91 1.94 1.93 1.93 1.95 1.95 1.95 1.93 1.91 1.24 1.64 1.84 1.84 1.86 1.86 1.84 1.86 1.91 0.15 I Ar 36 0.00041 0.00147 0.00025 0.00033 0.00031 0.0002 0.00018 0.00018 0.00028 0.00036 0.00044 0.00038 0.01606 0.01023 0.00478 0.00242 0.00127 0.00177 0.00299 0.00679 0.00348 0.00217 0.00077 0.00063 0.00149 0.0002 0.00024 0.00017 0.00016 0.00011 0.00011 0.00007 0.00011 Ar± 36 0.00001 0.00002 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00003 0.00001 0.00001 0 0.00001 0 0.00001 0 0.00001 0 0.00001 0.00001 0.00001 0 0.00001 0 0.00001 0.00001 0.00002 0 0.00001 T Ar 36 0.00041 0.00147 0.00025 0.00034 0.00031 0.0002 0.00019 0.00019 0.00029 0.00036 0.00044 0.00038 0.0161 0.01025 0.00478 0.00243 0.00128 0.00178 0.003 0.00681 0.0035 0.00221 0.00082 0.00063 0.00149 0.0002 0.00025 0.00017 0.00016 0.00011 0.00011 0.00007 0.00011 Ca Ar 37 0.00189 0.00907 0.00717 0.01293 0.0144 0.10146 0.01397 0.00965 0.01457 0.01424 0.0171 0.00235 0.02869 0.01373 0.00722 0.00756 0.00713 0.00954 0.01105 0.02107 0.0188 0.06558 0.12354 0.00124 0.00278 0.00166 0.00298 0.00264 0.00127 0.00219 0.00255 0.0011 0.00002 Cl Ar 38 0.00013 0.00011 0.00009 0.00018 0.00016 0.00013 0.00019 0.00014 0.00018 0.00011 0.00008 0.00041 0.03791 0.02334 0.01627 0.01514 0.01629 0.02347 0.03155 0.04639 0.03168 0.06002 0.0451 0.00039 0.00036 0.00008 0.00006 0.00003 0.00004 0.00005 0 0.00004 0.00001 Ar± 39 0.00003 0.00013 0.00023 0.00058 0.00133 0.0006 0.00085 0.00071 0.00026 0.00083 0.00055 0.00003 0.00098 0.00014 0.00005 0.00011 0.00014 0.0002 0.0004 0.00052 0.00048 0.00081 0.00055 0.00002 0.00005 0.00018 0.0001 0.0002 0.0003 0.00003 0.00015 0.00005 0.00002 K Ar 39 0.01466 0.30334 0.5736 1.17573 1.38181 1.13394 1.64997 1.9419 1.4189 1.47057 1.07961 0.01322 1.27194 0.71377 0.46739 0.41627 0.44327 0.63746 0.85178 1.27657 0.85246 1.5343 1.05129 0.01289 0.07759 0.13335 0.13776 0.30038 0.30166 0.2418 0.20222 0.068 0.00407 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.15087 1.0939 1.2982 2.60554 3.04913 2.49133 3.60538 2.61678 3.13451 3.27073 2.46042 0.13097 6.37879 4.27463 2.30573 1.51543 1.22694 1.74912 2.53694 4.47642 2.67981 3.59209 2.23718 0.20054 0.56374 0.3052 0.32468 0.61019 0.60793 0.47609 0.40781 0.15013 0.03067 Wt.=58.7 mg Wt.=60.2 mg Wt.=52.7 mg K Ar 40 0.00012 0.00284 0.00536 0.01099 0.01292 0.0106 0.01543 0.01117 0.01327 0.01375 0.01009 0.00012 0.01189 0.00667 0.00437 0.00389 0.00414 0.00596 0.00796 0.01194 0.00797 0.01435 0.00983 0.00011 0.00073 0.00125 0.00129 0.00281 0.00282 0.00225 0.00189 0.00064 0.00003 R Ar 40 0.0308 0.66292 1.22521 2.50771 2.95923 2.43378 3.55174 2.56292 3.05115 3.16623 2.33158 0.01979 1.62831 1.25064 0.89437 0.80666 0.85377 1.23016 1.66161 2.486 1.65841 2.95656 2.01089 0.01603 0.12725 0.24573 0.253 0.55955 0.56021 0.44375 0.37528 0.12999 -0.00063 SANIDINE BIOTITE FELDSPAR Ar± 40 4.00E-05 0.00013 0.0004 0.00133 0.00228 0.00144 0.00169 0.00133 0.00127 0.00147 0.00132 0.00017 0.00455 0.00164 0.00135 0.00009 0.00057 0.00058 0.00104 0.00248 0.00154 0.0018 0.00121 0.00021 0.00001 0.00018 0.00074 0.00036 0.00048 0.00011 0.00022 0.00004 0.00001 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.15099 1.09674 1.30356 2.61653 3.06205 2.50193 3.62081 2.62795 3.14778 3.28448 2.47051 0.13109 6.39068 4.2813 2.3101 1.51932 1.23108 1.75508 2.5449 4.48836 2.68778 3.60644 2.24701 0.20065 0.56447 0.30645 0.32597 0.613 0.61075 0.47834 0.4097 0.15077 0.0307 DRS-85-48/48/DD58 DRS-85-54/50/DD58 DRS-85-54/51/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 800 900 900 1100 1100 1000 1200 1250 1300 1350 1400 1450 1500 1600 1000 1000 1200 1300 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ 1100 1150 1050 1200 1250 1300 1350 1400 1500 TEMP ºC Sample: Sample: 40 J-value and its error: 0.006988±0.1% Plateau date: 26.86±0.04 Ma on steps: 5 to 10 containing 72.4% date: 26.83±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007531±0.1% containing 63.1% Plateau date: 26.00±0.05 Ma on steps: 5 to 11 date: 24.5±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007578±0.1% Plateau date: 25.13±0.19 Ma on steps: 5 to 8 containing 70.7% Ma date: 24.78±0.11 Total-gas Appendix 1. 48 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.33 0.4 0.11 0.04 0.05 0.04 0.06 0.04 0.04 0.06 0.05 0.12 0.33 0.3 0.19 0.09 0.11 0.12 0.12 0.12 0.12 0.12 0.12 0.15 0.23 1.18 0.09 0.12 0.05 0.07 0.04 0.04 0.04 0.05 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 26 26.3 26.5 26.6 26.5 26.6 26.5 26.8 26.8 26.7 26.8 27.5 27.2 41.7 50.7 60.9 72.8 75.8 77.5 80.4 80.2 80 80.2 77.8 12.1 25.1 27.3 27.2 27 26.9 26.9 26.8 26.8 26.9 Apparent Ar 39 0.3 1.8 5.2 9.2 7.8 9.8 9.9 1.6 0.6 0.5 1.5 3.7 9.5 4.2 0.7 0.6 2.7 5.3 7.5 9.1 9.5 11.8 11 11 16.9 14.5 14 19.3 10.3 12.8 12.6 18.8 26.3 19.5 %

8.8 8.8 Rad 42.4 89.6 94.7 94.9 95.8 96.5 97.2 97.2 97.3 97.1 92 22.9 51.5 70.1 66.2 89.2 94.9 93.7 91.3 92.8 95.6 97 93.4 10.7 71.8 89.2 83.5 93.8 95.4 94.6 93.5 92.8 yield K/Ca 3.11538 9.85075 4.56183 10.37087 15.49071 21.44816 29.86334 33.47726 38.04967 48.416 42.54504 43.43734 42.55893 34.87097 15.51835 44.83761 17.13504 38.78448 66.88372 36.75821 37.82936 10.64755 403.53869 288.71552 502.07222 156.01053 100.66444 109.39972 353.03887 F 2.08 1.95 1.95 1.95 1.95 1.96 1.96 1.97 1.97 1.97 1.97 2.02 2.06 3.1 3.77 4.54 5.43 5.66 5.78 6 5.99 5.98 5.99 5.81 0.97 1.97 2.01 2 1.99 1.98 1.98 1.89 1.97 1.98 I Ar 36 0.00233 0.00153 0.00036 0.00029 0.00024 0.00024 0.00022 0.00018 0.00026 0.00021 0.00016 0.00009 0.00094 0.00034 0.00057 0.00206 0.00215 0.00136 0.00099 0.00129 0.00113 0.00081 0.00053 0.00041 0.00203 0.00264 0.0006 0.00036 0.00082 0.00032 0.00047 0.00079 0.00073 0.0004 Ar± 36 0 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00002 0.00001 0 0 0 0 0 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00002 0.00001 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.00233 0.00153 0.00036 0.0003 0.00024 0.00025 0.00022 0.00018 0.00027 0.00021 0.00016 0.00009 0.00094 0.00034 0.00057 0.00206 0.00215 0.00136 0.00099 0.00129 0.00113 0.00081 0.00054 0.00041 0.00203 0.00264 0.0006 0.00037 0.00083 0.00034 0.00051 0.00084 0.00076 0.00042 Ca Ar 37 0.00507 0.00817 0.0156 0.02006 0.01222 0.01363 0.01349 0.01131 0.01854 0.01556 0.01086 0.00217 0.00201 0.00109 0.00117 0 0 0.00168 0 0.00116 0 0.0009 0.00285 0 0.00655 0.00137 0.0029 0.00225 0.00473 0.00354 0.00226 0.03168 0.02183 0.03802 Cl Ar 38 0.00076 0.00125 0.00022 0.00019 0.00013 0.00017 0.00022 0.00024 0.0003 0.00013 0.00006 0.00008 0.00028 0.00004 0.00008 0.00015 0.0002 0.00023 0.00013 0.00016 0.00013 0.00012 0.00011 0.00003 0.00144 0.00249 0.01134 0.02164 0.02972 0.0359 0.07508 0.10562 0.07698 0.03647 Ar± 39 0.00002 0.00007 0.0001 0.00047 0.00041 0.00044 0.00054 0.00011 0.00097 0.00058 0.00043 0.00003 0.00002 0.00001 0.00002 0.00012 0.00028 0.00072 0.00024 0.00029 0.00033 0.00056 0.00031 0.00015 0.00001 0.00002 0.00001 0.00026 0.00029 0.00046 0.00092 0.00112 0.0009 0.00006 K Ar 39 k 0.03159 0.16946 0.48331 0.8605 0.72986 0.91259 1.02658 1.09517 1.57757 1.35177 0.92438 0.15134 0.0396 0.03383 0.10492 0.26154 0.98592 1.35589 0.77167 0.66982 0.72507 0.90373 0.88926 0.29846 0.05976 0.04695 0.22495 0.45299 0.63272 0.77455 1.59856 2.329 1.65163 0.80964 k k Ar Ar Ar 39 39 39 I Ar 40 0.74821 0.77941 1.0472 1.76696 1.49259 1.85604 2.06671 2.11858 3.18316 2.71849 1.87216 0.33142 0.35589 0.20342 0.56272 1.79033 5.98171 8.06643 4.75412 4.3999 4.6737 5.63866 5.47969 1.85309 0.65652 0.86754 0.62692 1.00997 1.49854 1.6261 3.29527 4.63693 3.46491 1.71852 Wt.=51.5 mg Wt.=48.8 mg Wt.=34.9 mg K Ar 40 0.0003 0.00158 0.00452 0.00805 0.00682 0.00853 0.0096 0.10124 0.01475 0.01264 0.00864 0.00141 0.00037 0.00032 0.00098 0.00245 0.00922 0.01268 0.00722 0.00626 0.00678 0.00845 0.00831 0.00389 0.00056 0.00044 0.0021 0.00424 0.00592 0.00724 0.01495 0.02088 0.01544 0.00757 R Ar 40 0.06584 0.33098 0.94244 1.68126 1.42299 1.78478 2.0084 2.1576 3.10588 2.65733 1.82543 0.30632 0.08151 0.1049 0.39524 1.18691 5.35029 7.668 4.46328 4.02152 4.34229 5.40021 5.32307 1.73389 0.05789 0.09263 0.45187 0.90474 1.25746 1.53193 3.15723 4.40462 3.25215 1.60241 SANIDINE MUSCOVITE Ar± 40 0.00065 0.00017 0.0001 0.00095 0.00074 0.00092 0.00097 0.00021 0.00167 0.00106 0.00081 0.00013 0.00003 0 0.00005 0.00091 0.00275 0.00566 0.00171 0.00134 0.00213 0.00244 0.00258 0.00101 0.00052 0.00035 0.00006 0.00024 0.00062 0.0008 0.00188 0.00278 0.00231 0.00084 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.74851 0.78099 1.05172 1.77501 1.49941 1.86457 2.07631 2.21982 3.19791 2.73113 1.8808 0.33283 0.35626 0.20374 0.5637 1.79278 5.99093 8.07911 4.76134 4.40616 4.68048 5.64711 5.488 1.85698 0.65708 0.86798 0.62902 1.01421 1.50446 1.63334 3.31022 4.65781 3.48035 1.72609 DRS-85-78/53/DD58 DRS-85-78/52/DD58 DRS-85-122C/54/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 750 850 950 1100 1100 1150 1000 1200 1250 1300 1350 1400 1500 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1050 1200 1250 1300 1350 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.007602±0.1% containing 53.1% Plateau date: 26.78±0.06 Ma on steps: 8 to 11 date: 26.66±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.007606±0.1% containing 45.2% date: 80.2±0.14 Ma on steps: 8 to 11 Preferred date: 76.27±0.13 Ma Total-gas 40 J-value and its error: 0.007612±0.1% Plateau date: 26.85±0.05 Ma on steps: 6 to 10 containing 83.4% date: 26.79±0.06 Ma Total-gas Appendix 1. Appendix 1 49 5.42 0.83 0.13 0.52 0.8 0.47 0.54 0.13 0.16 0.13 0.13 0.13 2.77 0.21 0.05 0.09 0.06 0.05 0.05 0.07 0.05 0.05 0.08 1.34 1.47 0.52 0.07 0.05 0.05 0.05 0.12 0.11 0.07 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 83.8 83.8 82.5 82.1 82.6 82.9 83.2 84.4 86.8 86.2 84.4 18.1 28.5 32.9 33.1 33.1 33.2 33.2 33.3 33.4 33.4 33.1 35.2 33.9 31.8 32.2 32.8 33.2 32.7 32.9 33 33.1 118.9 Apparent Ar 39 0.6 1.1 2.8 2.6 2.4 2.3 2.6 3.3 4.6 0.1 1.1 5.1 7.6 5 6.7 7.9 3.1 0.9 1.2 2.7 7.6 11.6 23.1 42.1 12.6 12.6 27.3 23.6 16.5 18.7 17.6 13 10.4 %

4.2 8.9 Rad 20 37.1 51.4 57.6 61.6 64.7 67.9 70.1 81.7 87.5 78.4 31.8 82.6 93.2 94.7 95.8 94.4 97.3 98.2 98.3 94 23.4 35.6 28.3 45 82.1 87 86.6 83 82.4 86 yield K/Ca 0.00976 0.26329 0.3503 0.21123 0.15005 0.10644 0.08054 0.0719 0.06255 0.04681 0.04451 0.05148 0.62344 0.43193 2.74405 1.51904 0.39523 0.33998 0.12507 0.08858 0.10793 0.10753 0.11335 0.1197 0.1101 0.10917 21.24164 21.19628 22.15072 23.08424 23.02871 38.14336 32.5795 F 6.48 6.36 6.22 6.18 6.22 6.24 6.26 6.35 6.53 6.48 6.35 1.45 2.14 2.43 2.45 2.45 2.46 2.46 2.46 2.47 2.47 2.44 2.67 2.54 2.4 2.4 2.42 2.46 2.42 2.43 2.44 2.45 11.15 I Ar 36 0.01267 0.00256 0.00276 0.00139 0.00099 0.00081 0.0008 0.0009 0.00114 0.00308 0.00354 0.00201 0.00046 0.00159 0.0008 0.00041 0.0002 0.00021 0.00033 0.00023 0.0003 0.00025 0.00015 0.0007 0.00048 0.00146 0.00202 0.00055 0.00054 0.00063 0.00078 0.00061 0.00037 Ar± 36 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0 0 0.00002 0.00002 0 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0 0 0 0 0.00001 0.00001 0 T Ar 36 0.01288 0.00257 0.00278 0.00143 0.00105 0.00088 0.00091 0.00105 0.0014 0.0049 0.00702 0.00291 0.00046 0.00162 0.00083 0.00042 0.00021 0.00022 0.00035 0.00025 0.00035 0.00029 0.00018 0.00071 0.0005 0.00154 0.00233 0.00094 0.0011 0.00123 0.00132 0.00104 0.00072 Ca Ar 37 0.76352 0.05549 0.10838 0.16586 0.21842 0.29294 0.42933 0.61844 0.99026 6.67278 3.3024 0.00721 0.11752 0.08486 0.01645 0.01075 0.0139 0.01567 0.02508 0.03296 0.03327 0.09534 0.02997 0.04537 0.28349 1.14354 1.43732 2.04759 2.20808 1.96057 1.57627 1.27772 12.75325 Cl Ar 38 0.00062 0.00016 0.0004 0.00061 0.00094 0.00137 0.0022 0.00316 0.00565 0.03696 0.06268 0.01437 0.00023 0.00303 0.01706 0.026 0.01703 0.02322 0.02737 0.04341 0.09429 0.0815 0.01733 0.00025 0.00013 0.00028 0.0003 0.00022 0.0004 0.00059 0.00117 0.00169 0.00225 Ar± 39 0.00027 0.00004 0.00004 0.00002 0.00002 0.00004 0.00004 0.00001 0 0.0003 0.00036 0.00002 0.00002 0.00007 0.00024 0.00018 0.0002 0.00029 0.00036 0.00035 0.00125 0.00089 0.00001 0.00008 0.00008 0.00002 0.00005 0.00004 0.00021 0.00034 0.00028 0.00023 0.00005 K Ar 39 0.0149 0.02922 0.07593 0.07007 0.06555 0.06236 0.06916 0.08893 0.12389 0.62475 1.13521 0.34004 0.00899 0.10152 0.46572 0.69885 0.45572 0.61579 0.72346 1.15512 2.51441 2.16784 0.28965 0.02369 0.03085 0.07091 0.20258 0.31027 0.44036 0.50056 0.46936 0.34709 0.27897 k k Ar Ar 39 39 I Ar 40 3.9101 0.94586 1.29985 0.84651 0.6987 0.62582 0.66571 0.81944 1.12202 4.98992 8.403 2.75207 0.14695 0.68167 1.36824 1.8316 1.17457 1.57313 1.87514 2.91305 6.28874 5.41729 0.75042 0.26957 0.2199 0.59878 1.07842 0.91199 1.23919 1.39401 1.36962 1.02563 0.79193 Wt.=265.9 mg Wt.=56.4 mg Wt.=209.7 mg K Ar 40 0.00014 0.00027 0.00071 0.00066 0.00061 0.00058 0.00065 0.00083 0.00116 0.00584 0.01061 0.00318 0.00006 0.00095 0.00435 0.00653 0.00426 0.00576 0.00676 0.0108 0.02351 0.02027 0.00271 0.00022 0.00029 0.00066 0.00189 0.0029 0.00412 0.00468 0.00439 0.00325 0.00261 R Ar 40 0.16608 0.18946 0.48294 0.43583 0.40538 0.38772 0.43142 0.55682 0.78728 4.08097 7.35796 2.15894 0.01306 0.21696 1.13321 1.71274 1.11606 1.51184 1.777 2.84521 6.20064 5.34407 0.70791 0.06322 0.07834 0.16984 0.48654 0.75227 1.08136 1.21079 1.14049 0.84754 0.68277 Ar± 40 0.00246 0.00033 0.00066 0.00011 0.00038 0.00046 0.00018 0.00031 0.00019 0.00265 0.00444 0.00111 0 0.0004 0.00071 0.00054 0.00054 0.00062 0.00122 0.00049 0.00344 0.00264 0.00017 0.00003 0.00058 0.00021 0.00038 0.00014 0.0007 0.00069 0.00058 0.00044 0.00034 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 3.91024 0.94613 1.30056 0.84717 0.69931 0.6264 0.66636 0.82027 1.12318 4.99576 8.41361 2.75525 0.14701 0.68262 1.37259 1.83813 1.17883 1.57889 1.8819 2.92385 6.31225 5.43756 0.75313 0.26976 0.22015 0.59936 1.08009 0.91454 1.24282 1.39813 1.37348 1.02849 0.79423 DRS-85-128/36/DD58 DRS-85-176/56/DD58 DRS-85-176/55/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 750 850 950 1150 1100 1100 1150 1000 1200 1250 1275 1300 1325 1350 1375 1400 1450 1600 1000 1200 1250 1300 1350 1400 1500 1050 1250 1350 1450 1550 1650 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007595±0.1% No plateau date: 85.63±0.2 Ma Total-gas Sample: 40 J-value and its error: 0.007581±0.1% Plateau date: 33.35±0.06 Ma on steps: 8 to 10 containing 63.5% date: 33.2±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.0076±0.1% Plateau date: 32.93±0.08 Ma on steps: 5 to 10 containing 87.7% Ma date: 32.87±0.11 Total-gas Appendix 1. 50 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.89 0.17 0.07 0.04 0.05 0.05 0.04 0.04 0.04 0.07 0.17 0.19 0.19 0.04 0.13 0.04 0.07 0.07 0.05 0.04 0.04 0.06 0.05 0.04 0.1 0.12 0.04 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.05 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

9.8 age 27.5 28.3 27.2 27.2 27 27.2 27.2 27.3 27.3 27.4 27.2 17.5 22.7 26.7 27.4 27.6 27.4 27.6 27.5 27.1 27 26.8 24.9 28.2 27.2 27 26.9 26.9 26.9 26.9 27 27 27 27 Apparent Ar 39 0.3 1.9 4.8 8.4 9.6 3.4 1.6 2.3 4.5 9.2 9 7.3 7.4 4.8 4.8 3.5 2.8 6 4.8 7 8.8 11.8 11.5 14.1 14.4 16.7 14.4 % 15.5 14.9 12.1 10.9 10.9 12.3 14.3 13.8

Rad 15.2 39.3 88.4 94.4 95.9 97.5 97.6 97.9 98.1 97.8 94.2 14.1 38.4 40.7 68.2 78.8 80.6 79 73.1 72.9 81.5 84.1 85.1 58 55.7 69.5 79.9 85 88.2 92.2 94.3 95.3 97.2 97.5 95.5 yield K/Ca 6.13312 4.21297 5.61641 6.80056 9.62707 11.42952 20.63039 31.17362 35.17864 47.37277 46.98909 45.79863 58.98099 49.42346 39.22692 17.7 21.54362 25.1371 39.73273 56.40476 60.29817 70.8809 38.41014 21.36151 15.13128 24.12394 10.30011 15.16146 18.43948 22.79734 30.68134 41.59143 49.26045 56.62635 38.3276 F 2.14 2.14 2.03 2.03 2.01 2.03 2.03 2.03 2.04 2.04 2.03 0.72 1.29 1.67 1.97 2.02 2.04 2.02 2.03 2.03 2 1.99 1.98 1.86 2.11 2.02 2.01 2 2 2 2 2 2 2 2.01 I Ar 36 0.00155 0.00252 0.00049 0.00037 0.0003 0.00025 0.00019 0.0002 0.00021 0.00022 0.00016 0.0023 0.00141 0.00339 0.00257 0.00148 0.00108 0.0012 0.00261 0.00356 0.00204 0.00136 0.0005 0.0029 0.00264 0.00113 0.00132 0.00075 0.00082 0.00064 0.00055 0.00044 0.00028 0.00027 0.00053 Ar± 36 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0 0.00003 0.00002 0.00001 0.00001 0 0.00002 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 T Ar 36 0.00155 0.00253 0.0005 0.00038 0.0003 0.00025 0.00019 0.00021 0.00022 0.00022 0.00016 0.0023 0.00141 0.0034 0.00258 0.00149 0.00109 0.00121 0.00262 0.00358 0.00206 0.00137 0.00052 0.00291 0.00265 0.00113 0.00133 0.00076 0.00083 0.00065 0.00055 0.00044 0.00028 0.00028 0.00054 Ca Ar 37 0.00308 0.02667 0.01369 0.01581 0.01601 0.01741 0.01467 0.0183 0.01657 0.01705 0.00509 0.00415 0.0047 0.00806 0.01042 0.00714 0.00545 0.00466 0.01341 0.03271 0.04422 0.02251 0.0387 0.04673 0.02412 0.01826 0.03455 0.02112 0.02528 0.02561 0.02352 0.01739 0.01651 0.0167 0.02384 Cl Ar 38 0.00032 0.00037 0.00004 0.00011 0.00005 0.00014 0.00012 0.00008 0.00009 0.00004 0 0.00362 0.0053 0.01122 0.02398 0.0225 0.01812 0.01814 0.0284 0.03885 0.0369 0.02989 0.01336 0.00258 0.00075 0.00051 0.00034 0.00014 0.00022 0.00022 0.00038 0.00052 0.00055 0.00019 0.00006 Ar± 39 0.00002 0.00013 0.00044 0.00035 0.00054 0.00088 0.00075 0.00115 0.00109 0.00029 0.00012 0 0.00007 0.00011 0.00037 0.00018 0.00033 0.00035 0.00041 0.00038 0.00072 0.00042 0.00021 0.00044 0.00002 0.00003 0.00027 0.00014 0.00001 0.00045 0.00081 0.00079 0.00083 0.0008 0.00091 K Ar 39 0.03778 0.22472 0.56486 0.98571 1.12642 1.64952 1.37866 1.67623 1.95463 1.68534 0.39933 0.14691 0.20251 0.40521 0.82803 0.80546 0.65725 0.66061 1.03016 1.39747 1.33821 1.08606 0.43471 0.63558 0.46441 0.37616 0.78978 0.64042 0.9323 1.16768 1.44325 1.44655 1.62658 1.89132 1.82746 k k Ar Ar 39 39 I Ar 40 0.53386 1.21945 1.29172 2.1065 2.35611 3.41592 2.84886 3.46822 4.0425 3.49841 0.85717 0.78394 0.67655 1.67909 2.38931 2.06635 1.66105 1.69129 2.8656 3.88926 3.28016 2.56222 1.00691 2.0301 1.75297 1.09187 1.97492 1.50113 2.10421 2.52005 3.04722 3.02351 3.34087 3.86573 3.82013 Wt.=54.7 mg Wt.=66.7 mg Wt.=55.7 mg K Ar 40 0.00035 0.0021 0.00528 0.00922 0.01053 0.01542 0.01289 0.01567 0.01828 0.01576 0.00373 0.0012 0.00166 0.00332 0.00679 0.0066 0.00539 0.00542 0.00845 0.01146 0.01097 0.00891 0.00356 0.00594 0.00434 0.00352 0.00738 0.00599 0.00872 0.01092 0.01349 0.01353 0.01521 0.01768 0.01709 R Ar 40 0.08093 0.4805 1.14762 1.9967 2.26949 3.34299 2.79302 3.40905 3.9807 3.4347 0.81071 0.10541 0.26031 0.67763 1.62925 1.63008 1.34099 1.3377 2.09544 2.83807 2.67875 2.16141 0.85934 1.18095 0.97818 0.7608 1.58678 1.28129 1.86348 2.33264 2.88662 2.89501 3.25917 3.78514 3.66412 SANIDINE SANIDINE Ar± 40 0.00019 0.0008 0.00054 0.00103 0.00126 0.00181 0.00145 0.00128 0.00167 0.00072 0.0002 0.00048 0.00002 0.00095 0.00069 0.00036 0.00085 0.00073 0.0013 0.00131 0.00133 0.00114 0.0005 0.00133 0.00023 0.00016 0.00099 0.00003 0.00034 0.00104 0.0021 0.00158 0.00158 0.00207 0.00198 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.53421 1.22155 1.297 2.11572 2.36664 3.43134 2.86175 3.48389 4.06078 3.51417 0.8609 0.78515 0.67821 1.68241 2.3961 2.07295 1.66644 1.69671 2.87405 3.90072 3.29114 2.57112 1.01047 2.03604 1.75731 1.09539 1.9823 1.50712 2.11293 2.53097 3.06071 3.03704 3.35608 3.88341 3.83722 DRS-85-224/57/DD58 DRS-85-224/58/DD58 DRS-85-225/59/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 900 1150 1100 1150 1100 1100 1000 1200 1250 1300 1350 1400 1450 1550 1000 1200 1250 1300 1350 1400 1450 1500 1600 1000 1200 1250 1300 1350 1400 1450 1500 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: Sample: 40 J-value and its error: 0.007507±0.1% containing 74.8% Plateau date: 27.30±0.08 Ma on steps: 6 to 11 date: 27.26±0.06 Ma Total-gas 40 J-value and its error: 0.007565±0.1% Plateau date: Disturbed and undetermined date: 26.54±0.07 Ma Total-gas 40 J-value and its error: 0.007537±0.1% Plateau date: 26.98±0.05 Ma on steps: 4 to 12 containing 88.9% date: 26.91±0.05 Ma Total-gas Appendix 1. Appendix 1 51 0.83 4.14 2.3 2.21 8.25 0.33 0.06 0.05 0.04 0.06 0.17 0.04 11.51 0.09 0.24 0.04 0.14 0.04 0.06 0.04 0.04 0.04 0.05 0.05 1.29 1.47 0.58 0.08 0.04 0.07 0.04 0.04 0.04 0.04 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 48.6 27.6 38.2 27.1 33.8 28.5 26.9 27.1 27.2 27.4 27.3 27.5 18.5 27.8 28.1 27.3 27.3 27.2 27.2 27.2 27.3 27.3 27.4 27.5 19.7 26.7 28.4 27.8 27.9 27.5 27.5 27.5 27.4 27.6 Apparent Ar 39 0.2 0.3 0.3 0.3 0.4 1.4 0 0.8 2.1 5.7 4.2 5.7 8.5 0.1 0.3 0.6 2.6 8.5 11.4 11.5 11.9 10.4 17 28.4 18.5 12.4 10.4 16.4 21.6 12.9 19.4 16.3 14.2 25.2 %

7.51 3.4 3.76 2.91 Rad yield 23.89 17.12 23.35 39.65 62.61 77.13 83.35 81.57 76.31 74.79 25.42 38.41 70.13 84.9 88.35 93.8 94.91 95.26 96.94 95.83 94.51 13.79 18.38 58.58 82.35 87.9 87.91 80.5 73.02 73.03 K/Ca 0.39752 0.31223 0.36977 0.34663 0.28207 0.13002 0.09808 0.0979 0.09898 0.09821 0.09299 0.09174 8.75062 1.10224 4.21555 4.46661 4.19763 92.5 12.16602 12.82949 16.58206 18.72322 23.56131 27.3348 28.14169 33.27669 39.55092 38.44285 13.66328 35.651 79.53685 99.22304 12.53803 10.83031 F 3.8 2.15 2.98 2.1 2.64 2.22 2.09 2.11 2.12 2.13 2.12 2.14 1.46 2.19 2.22 2.16 2.15 2.15 2.15 2.15 2.15 2.15 2.16 2.18 1.54 2.09 2.22 2.18 2.19 2.15 2.16 2.16 2.15 2.16 I Ar 36 0.00101 0.00176 0.0003 0.00031 0.00037 0.00052 0.0014 0.00114 0.00127 0.00095 0.00088 0.0008 0.00023 0.00153 0.00224 0.00154 0.00047 0.00046 0.00033 0.00036 0.00033 0.00028 0.00054 0.00041 0.0012 0.00105 0.00188 0.00132 0.00127 0.00122 0.00182 0.00275 0.00366 0.00651 Ar± 36 0 0.00001 0.00001 0.00001 0.00003 0 0 0.00001 0 0.00001 0.00002 0 0.00001 0 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0 0.00001 0.00001 0 0.00001 0.00001 0 0.00001 0.00001 0.00001 0 0 0.00001 T Ar 36 0.00102 0.00177 0.0003 0.00032 0.00038 0.00057 0.00188 0.00192 0.00256 0.00179 0.00147 0.00131 0.00023 0.00154 0.00224 0.00155 0.00047 0.00047 0.00034 0.00036 0.00034 0.00029 0.00055 0.00042 0.0012 0.00105 0.00188 0.00133 0.00129 0.00123 0.00185 0.00278 0.00372 0.00657 Ca Ar 37 0.00805 0.01366 0.01267 0.01304 0.02253 0.17616 1.69783 2.78431 4.59831 3.01898 2.1413 1.81811 0.00001 0.00403 0.00768 0.01953 0.01115 0.01335 0.01574 0.01819 0.01782 0.02154 0.02386 0.01356 0.00313 0.00283 0.00629 0.00934 0.01149 0.00787 0.00946 0.06311 0.16399 0.11262 Cl Ar 38 0.00122 0.0003 0.00041 0.0007 0.00141 0.00718 0.0604 0.09631 0.13167 0.06684 0.05291 0.04791 0.00005 0.00008 0.00011 0.00008 0.00003 0.00004 0.00002 0.00003 0.00003 0.00003 0 0 0.00026 0.00061 0.00156 0.00872 0.02599 0.03661 0.0547 0.04743 0.04413 0.07365 Ar± 39 0.00026 0.00005 0.00002 0.00003 0.00003 0.00001 0.00012 0.00118 0.00013 0.00035 0.00019 0.00036 0.00002 0.00007 0.0001 0.00043 0.00027 0.00016 0.00082 0.00062 0.00031 0.0012 0.00118 0.0005 0.00025 0.00001 0.00003 0.00013 0.00021 0.00375 0.00183 0.00082 0.00131 0.00095 K Ar k 39 Ar 0.0064 0.00853 0.00937 0.00904 0.01271 0.04581 0.33306 0.54516 0.91026 0.593 0.39824 0.33357 0.00185 0.07053 0.18687 0.50112 0.36978 0.49991 0.74171 0.99444 1.00297 1.43356 1.88737 1.04257 0.0069 0.02386 0.05619 0.25523 0.81926 1.25191 1.8773 1.58255 1.37674 2.43942 k k 39 Ar Ar 39 39 I Ar 40 0.32422 0.53879 0.11686 0.11104 0.14336 0.25604 1.10906 1.48643 2.30447 1.54362 1.10493 0.95045 0.0717 0.60829 1.07625 1.5376 0.93479 1.20939 1.69373 2.24228 2.25805 3.16823 4.2359 2.38969 0.36526 0.3611 0.67938 0.94761 2.17012 3.05451 4.5872 4.2252 4.04034 7.19597 Wt.=80.1 mg Wt.=205.7 mg Wt.=52.8 mg K Ar 40 0.00006 0.00008 0.00009 0.00008 0.00012 0.00043 0.00311 0.0051 0.00851 0.00554 0.00372 0.00312 0.00002 0.00066 0.00175 0.00469 0.00346 0.00467 0.00693 0.0093 0.00938 0.0134 0.01765 0.00975 0.00006 0.00022 0.00053 0.00239 0.00766 0.01171 0.01755 0.0148 0.01287 0.02281 R Ar 40 0.02434 0.0183 0.02794 0.01902 0.0335 0.1017 0.69632 1.15045 1.92797 1.26366 0.84602 0.71319 0.0027 0.15479 0.41402 1.08156 0.7966 1.07261 1.59526 2.13689 2.16005 3.08434 4.07617 2.26782 0.01064 0.04984 0.12495 0.55648 1.79342 2.69533 4.04815 3.41327 2.95956 5.27153 BIOTITE AMPHIBOLE SANIDINE Ar± 40 0.00117 0.00009 0.00007 0.0003 0.00033 0.00022 0.00038 0.00421 0.00066 0.00099 0.00061 0.00028 0.00004 0.001 0.00066 0.00169 0.00006 0.00116 0.00028 0.00121 0.00028 0.00064 0.0003 0.00079 0.00112 0.00025 0.00011 0.00029 0.00029 0.00481 0.00105 0.00333 0.00071 0.0026 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.32428 0.53886 0.11695 0.11112 0.14348 0.25647 1.11217 1.49152 2.31298 1.54916 1.10865 0.95357 0.07172 0.60895 1.078 1.54229 0.93824 1.21407 1.70066 2.25157 2.26742 3.18163 4.25355 2.39943 0.36532 0.36132 0.6799 0.95 2.17778 3.06621 4.60475 4.23999 4.05321 7.21878 DRS-91-17/20/DD57 DRS-91-17/21/DD57 DRS-91-17/19/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 900 1100 1100 1100 1000 1200 1250 1300 1350 1400 1550 1000 1200 1275 1325 1375 1400 1425 1450 1500 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.00718±0.1% date: 27.39±0.09 Ma on steps: 10 to 12 containing 41.3% Preferred Ma date: 27.36±0.11 Total-gas Sample: 40 J-value and its error: 0.007073±0.1% Plateau date: 27.24±0.06 Ma on steps 4 to 10 containing 63.4% date: 27.32±0.06 Ma Total-gas 40 J-value and its error: 0.007126±0.1% Plateau date: 27.51±0.05 Ma on steps: 6 to 10 containing 88.0% date: 27.55±0.05 Ma Total-gas Appendix 1. 52 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.37 0.07 0.11 0.2 0.06 0.08 0.2 0.09 0.04 0.04 3.88 0.55 3.35 0.6 0.09 0.06 0.11 0.58 1.1 0.08 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.09 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

7 age 16 23.8 25.7 27.6 28.1 27.8 28 27.5 27.4 12.1 33.5 27 26.2 26.7 26.9 27.3 26.9 15.8 27 27.7 27.1 26.8 27 27 27 27 27 27.1 27 Apparent Ar 1.3 8.6 7.1 8.5 9 1.4 2.9 1.7 2.8 7.6 0.2 3 3.9 8.9 6.9 8.7 3.7 39 11.9 11.1 10.6 13.7 16.6 13.6 22.1 44.3 17.2 12.9 13 13.5 13.4 %

3.38 7.41 Rad yield 11.76 23.02 32.22 45.88 61.18 62.63 57.99 57.72 66.48 76.33 29.72 32.92 68.58 79.78 74.28 61.05 17.56 80.75 64.32 95.43 95.5 96.82 97.83 97.75 97.9 97.83 97.55 94.25 K/Ca 7.40711 8.5756 1.70188 1.16223 0.85053 0.09422 0.07443 0.07239 0.07706 0.07772 3.77528 6.94455 9.75902 15.85766 30.00672 24.90323 26.50116 38.95299 28.37957 25.53759 15.2326 14.18527 18.48553 23.70705 30.29888 37.27565 50.06384 55.59949 47.53657 26.65044 F 0.54 1.23 1.84 1.99 2.14 2.17 2.15 2.17 2.13 2.12 0.92 2.58 2.07 2.02 2.06 2.07 2.1 2.07 1.22 2.09 2.13 2.09 2.07 2.09 2.08 2.08 2.08 2.08 2.09 2.08 I Ar 36 0.00225 0.00497 0.00363 0.00181 0.00125 0.00149 0.00153 0.00236 0.00194 0.00096 0.00057 0.00194 0.00029 0.0004 0.00072 0.0008 0.00043 0.00035 0.00039 0.00049 0.00148 0.00026 0.0002 0.00017 0.00016 0.00017 0.00016 0.00016 0.00017 0.00014 Ar± 36 0 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0 0 0.00002 0 0.00001 0 0 0 0 0.00001 0.00001 0.00001 0 0 0 0 0 0 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.00225 0.00498 0.00363 0.00182 0.00125 0.00149 0.00154 0.00237 0.00195 0.00097 0.00057 0.00194 0.0003 0.00044 0.00115 0.00168 0.00075 0.00049 0.00039 0.00049 0.00149 0.00027 0.0002 0.00017 0.00016 0.00017 0.00016 0.00017 0.00017 0.00015 Ca Ar 37 0.00137 0.00595 0.00558 0.00432 0.00351 0.00602 0.00572 0.01451 0.03628 0.02553 0.00426 0.01276 0.01047 0.15379 1.53119 3.15681 1.14851 0.5032 0.00267 0.02119 0.01913 0.03028 0.01797 0.01787 0.02056 0.01696 0.01308 0.01171 0.01217 0.00678 Cl Ar 38 0.00138 0.00941 0.00766 0.00649 0.0077 0.00945 0.00805 0.01217 0.01524 0.01238 0.00056 0.00085 0.00078 0.00232 0.03895 0.08028 0.02991 0.01315 0.00011 0.00064 0.00037 0.00028 0.00015 0.00024 0.0003 0.0004 0.00014 0 0.00002 0 Ar± 39 0.00002 0.0003 0.00012 0.00017 0.00002 0 0.00033 0.0004 0.00033 0.00039 0.00042 0.00004 0 0.00003 0.00018 0.00019 0.00014 0.00008 0.00002 0.00032 0.00029 0.00006 0.00073 0.00083 0.00096 0.00118 0.00086 0.00082 0.00132 0.00038 K Ar 39 0.04345 0.35708 0.27792 0.22897 0.27345 0.34169 0.29215 0.44205 0.53746 0.43787 0.0145 0.02966 0.01781 0.02898 0.22793 0.45703 0.17701 0.07822 0.02016 0.29431 0.37338 0.85906 0.66437 0.84729 1.24589 1.26439 1.30967 1.30214 1.15704 0.36138 k k Ar Ar 39 I 39 Ar 40 0.68793 1.9105 1.58356 0.99148 0.95241 1.18287 1.08049 1.65799 1.71641 1.21213 0.18084 0.64937 0.12405 0.1772 0.68099 1.1805 0.49883 0.26391 0.13955 0.75731 1.2354 1.87034 1.43378 1.81764 2.63815 2.67997 2.77687 2.76196 2.47037 0.79568 Wt.=29.2 mg Wt.=84.7 mg Wt.=59.8 mg K Ar 40 0.00041 0.00334 0.0026 0.00214 0.00256 0.00319 0.00273 0.00413 0.00503 0.00409 0.00014 0.00028 0.00017 0.00027 0.00213 0.00427 0.00166 0.00073 0.00019 0.00275 0.00349 0.00803 0.00621 0.00792 0.01165 0.01182 0.01225 0.01218 0.01082 0.00338 R Ar 40 0.02328 0.44052 0.51107 0.45589 0.58426 0.74288 0.62817 0.95932 1.1444 0.92838 0.01341 0.07642 0.03691 0.05842 0.46852 0.94524 0.37177 0.16157 0.02454 0.61373 0.79688 1.79253 1.37524 1.76759 2.59229 2.63111 2.73044 2.71406 2.42051 0.75311 BIOTITE AMPHIBOLE SANIDINE Ar± 40 0.00012 0.00118 0.00028 0.0005 0.00037 0.00042 0.00061 0.00016 0.00097 0.00072 0.00171 0.00008 0.0002 0.00008 0.00017 0.00011 0.00026 0.00028 0.00005 0.00088 0.00123 0.00085 0.00143 0.00114 0.00098 0.00186 0.00153 0.00288 0.00386 0.0006 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.68834 1.91384 1.58616 0.99362 0.95496 1.18607 1.08322 1.66213 1.72144 1.21622 0.18097 0.64964 0.12422 0.17747 0.68312 1.18477 0.50049 0.26464 0.13974 0.76007 1.23889 1.87837 1.43999 1.82556 2.6498 2.69179 2.78912 2.77414 2.48119 0.79906 DRS-91-31/22/DD57 DRS-91-31/24/DD57 DRS-91-31/23/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 850 950 950 900 1100 1100 1100 1050 1200 1300 1350 1400 1450 1550 1200 1300 1375 1425 1500 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007214±0.1% date: Disturbed and undetermined Preferred date: 25.66±0.1 Ma Total-gas Sample: 40 J-value and its error: 0.007266±0.1% Plateau date: 26.85±0.14 Ma on steps 5 to 6 containing 66.4% date: 26.9±0.31 Ma Total-gas Sample: 40 J-value and its error: 0.00724±0.1% Plateau date: 27.01±0.04 Ma on steps 6 to 12 containing 77.2% date: 27.01±0.05 Ma Total-gas Appendix 1. Appendix 1 53 3.22 0.03 0.13 0.06 0.12 0.21 0.07 0.09 0.16 0.03 0.04 0.03 0.15 0.13 0.09 0.05 0.07 0.07 0.05 0.04 0.05 0.08 0.27 0.81 0.88 0.47 0.22 0.05 0.04 0.04 0.06 0.04 0.05 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 14.9 18.6 24.2 26.6 26.9 26.7 26.1 26.3 26.2 26.1 26.1 25.9 15.8 20.2 22.7 25.1 25.5 25.6 25.6 25.6 25.7 26 26.2 14.9 18.9 29.5 27.2 28 27.4 27.4 27.3 27.6 28.3 Apparent Ar 0.1 5.4 6.7 6 4.7 3 2.5 4.9 4.1 3.8 2.6 4.9 8.7 8.1 1.6 0.3 0.4 0.5 2 8.3 9.1 39 11.3 13.7 16.3 32.7 12 12.6 16.9 17.6 22.1 24.5 15.4 17.5 %

3.75 Rad 16.23 31.37 42.93 47.44 56.09 54.1 66.38 70.38 69.51 71.8 84.43 23.62 38.42 84.24 92.43 93.38 94.35 95.81 96.78 96.73 94.45 75.33 12.24 21.86 15.83 53.48 83.32 91.58 89.22 82.15 83.55 79.99 yield K/Ca 6.39678 5.1653 4.84513 5.4827 8.0887 6.74093 3.20492 9.89826 11.85098 28.67715 67.5342 42.73212 40.27381 41.74811 32.46588 40.60966 30.74828 36.43239 23.94227 17.52933 16.29399 19.85653 26.19675 23.34594 14.83333 26.46154 58.33188 37.21942 74.06918 23.47171 441.5 120.38041 126.53389 F 1.14 1.42 1.85 2.04 2.06 2.05 2 2.01 2 2 2 1.98 1.2 1.54 1.74 1.91 1.95 1.96 1.95 1.96 1.96 1.98 2 1.13 1.44 2.25 2.07 2.13 2.09 2.08 2.08 2.11 2.16 I Ar 36 0.00087 0.01465 0.00998 0.006 0.0039 0.00179 0.00158 0.00181 0.00126 0.0044 0.00466 0.0043 0.00411 0.00179 0.00043 0.00036 0.00043 0.00034 0.00027 0.00026 0.00028 0.00024 0.00029 0.00064 0.00059 0.00155 0.00096 0.00095 0.0011 0.00162 0.00186 0.00194 0.00132 Ar± 36 0.00001 0.00001 0.00002 0.00001 0.00001 0.00002 0 0.00001 0.00001 0 0.00003 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 T Ar 36 0.00087 0.01466 0.00999 0.00601 0.00391 0.00179 0.00158 0.00182 0.00127 0.00442 0.0047 0.00438 0.00412 0.00179 0.00044 0.00038 0.00045 0.00035 0.00028 0.00027 0.00029 0.00025 0.00029 0.00064 0.00059 0.00155 0.00096 0.00095 0.00111 0.00164 0.00187 0.00195 0.00133 Ca Ar 37 0.00001 0.01033 0.00541 0.00769 0.0063 0.00397 0.00425 0.00652 0.00725 0.02056 0.03707 0.10176 0.02451 0.02075 0.04168 0.06559 0.06122 0.03929 0.03177 0.03506 0.02765 0.01428 0.00992 0.00366 0.00172 0.00129 0.00299 0.00574 0.0074 0.00782 0.01668 0.00954 0.01573 Cl Ar 38 0.00013 0.01744 0.02482 0.02355 0.01843 0.01217 0.01027 0.01977 0.01661 0.05599 0.06697 0.13597 0.00029 0.00007 0 0 0.00016 0 0.00001 0 0 0 0.00006 0.00037 0.00039 0.00079 0.00322 0.01229 0.03079 0.03348 0.02151 0.02432 0.01366 Ar± 39 0.00003 0.00014 0.00048 0.00026 0.0002 0.00018 0.00018 0.00019 0.00061 0.00136 0.00103 0.00368 0.00004 0.00014 0.00051 0.00029 0.00031 0.00052 0.00096 0.00013 0.00035 0.00025 0.00003 0.00002 0.00001 0.00003 0.00012 0.00031 0.00085 0.00087 0.00153 0.00032 0.00013 K Ar 39 k 0.00883 0.59247 0.73072 0.65722 0.50745 0.33148 0.27596 0.52955 0.44585 1.4981 1.77508 3.56757 0.31357 0.21436 0.40389 0.71922 0.99038 0.93125 1.03532 1.39234 1.44868 0.66676 0.13374 0.02346 0.03405 0.03827 0.15824 0.66965 1.78163 1.97899 1.24164 1.41324 0.73842 Ar k k 39 Ar Ar I 39 39 Ar 40 0.26774 5.16893 4.29922 3.10969 2.19688 1.20582 1.01707 1.60099 1.265 4.29259 4.92818 8.34086 1.59251 0.85861 0.82827 1.48187 2.05658 1.92235 2.10028 2.79968 2.92262 1.39316 0.35369 0.21589 0.22389 0.54356 0.6119 1.70704 4.04018 4.60316 3.12601 3.54787 1.98361 Wt.=94.6 mg Wt.=67.5 mg Wt.=61.5 mg K Ar 40 0.00008 0.00554 0.00683 0.00614 0.00474 0.0031 0.00258 0.00495 0.00417 0.01401 0.0166 0.03336 0.00293 0.002 0.00378 0.00672 0.00926 0.00871 0.00968 0.01302 0.01355 0.00623 0.00125 0.00022 0.00032 0.00036 0.00148 0.00626 0.01666 0.0185 0.01161 0.01321 0.0069 R Ar 40 0.01004 0.83996 1.35075 1.3376 1.04456 0.67806 0.55159 1.06599 0.89321 2.9934 3.55031 7.07066 0.37678 0.33065 0.70091 1.37598 1.92908 1.82199 2.02149 2.72217 2.84011 1.32176 0.26737 0.02645 0.049 0.08611 0.32806 1.4276 3.71529 4.12362 2.57765 2.97513 1.59214 BIOTITE SANIDINE BIOTITE Ar± 40 0.00016 0.00168 0.00159 0.0004 0.00032 0.00003 0.00035 0.00042 0.00013 0.00354 0.00492 0.00233 0.0004 0.00048 0.00011 0.00116 0.00038 0.00098 0.00013 0.00074 0.00042 0.00024 0.00059 0.00045 0.00011 0.0005 0.00032 0.00039 0.00103 0.00177 0.00055 0.00083 0.00021 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.26783 5.17447 4.30605 3.11583 2.20163 1.20892 1.01965 1.60594 1.26916 4.3066 4.94478 8.37421 1.59544 0.86061 0.83204 1.4886 2.06584 1.93105 2.10996 2.8127 2.93616 1.39939 0.35494 0.21611 0.22421 0.54392 0.61338 1.7133 4.05684 4.62166 3.13762 3.56108 1.99052 DRS-91-74/25/DD57 DRS-91-74/26/DD57 DRS-91-82/27/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 800 900 900 800 900 1100 1150 1100 1100 1000 1050 1200 1250 1300 1350 1400 1550 1000 1200 1300 1350 1400 1450 1500 1550 1600 1000 1200 1300 1350 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007291±00% containing 41.4% date: 26.13±0.08 Ma on steps 7 to 11 Preferred date: 25.58±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.00731±0.1% Plateau date: 25.61±0.05 Ma on steps 5 to 9 containing 60.3% date: 24.94±0.07 Ma Total-gas Sample: 40 J-value and its error: 0.007335±0.1% Plateau date: 27.35±0.05 Ma on steps 6 to 8 containing 61.9% date: 27.48±0.06 Ma Total-gas Appendix 1. 54 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.73 0.25 0.05 0.14 0.05 0.09 0.05 0.05 0.04 0.04 0.06 0.21 0.16 0.17 0.07 0.05 0.05 0.04 0.05 0.04 0.04 0.04 0.04 0.05 0.99 1.3 0.82 0.09 0.04 0.04 0.08 0.04 0.04 0.08 0.38 11.39 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

9.4 age 27.4 27.1 27.3 27 27.2 27.3 27.3 27.4 27.4 27.4 27.4 32.2 27.9 27.8 27.7 27.7 27.5 27.3 27.3 27.3 27.3 27.3 27.5 27.5 23.8 20.8 24.3 27 27.2 27.1 27.1 27 27 27.1 26.3 Apparent Ar 39 0.1 1.1 2.5 6.9 6 6.9 8 1.2 2.8 2 3.4 4.7 8.2 9.5 9 8 0.4 0.5 0.9 3.9 9.1 8.8 1.9 11.7 11.3 10.1 22.3 13.2 13.3 13.9 10.7 13.5 17.7 22.2 22.7 12 %

9.4 Rad yield 11.07 57.55 59.13 94.34 94.46 95.52 96.53 97.29 97.01 97.13 97.11 96.14 13.2 44.5 52.6 80.3 85.2 89.6 92.6 93.2 92.4 89.1 83.5 78.5 78 18.8 15.6 61.5 83.7 88.1 88.7 86.6 84.4 85.8 79.6 K/Ca 3.01744 3.31005 7.77544 1.17165 6.39804 1.44377 2.2805 2.69465 13.72426 13.7262 17.27722 19.85562 23.32615 27.70925 30.79483 29.91156 29.71655 25.03098 21.84127 30.57727 37.85255 77.53592 95.32118 93.51786 74.52496 31.61171 22.00255 12.40064 74.84834 53.33883 86.78865 42.14206 40.1155 25.84202 128.51687 100.70486 F 0.71 2.08 2.06 2.07 2.05 2.07 2.07 2.08 2.08 2.08 2.08 2.08 2.53 2.09 2.08 2.06 2.05 2.04 2.03 2.03 2.03 2.02 2.03 2.04 2.04 1.88 1.57 1.86 1.99 2 1.99 1.99 1.99 1.99 1.99 1.94 I Ar 36 0.0001 0.00056 0.00115 0.00026 0.00022 0.0002 0.00017 0.00019 0.00018 0.00019 0.00039 0.00032 0.00648 0.00238 0.00122 0.00056 0.00054 0.00062 0.00068 0.00064 0.00056 0.00075 0.00116 0.00145 0.00252 0.00185 0.00095 0.00228 0.00132 0.00096 0.00063 0.0012 0.00184 0.00225 0.00107 0.00026 Ar± 36 0.00001 0.00002 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00002 0.00001 0.00001 0.00001 0 0 0.00001 0.00001 0.00001 0 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00003 0 0.00001 0.00002 0.00001 T Ar 36 0.0001 0.00056 0.00115 0.00027 0.00022 0.0002 0.00018 0.00019 0.00019 0.0002 0.0004 0.00033 0.00649 0.00239 0.00123 0.00057 0.00055 0.00063 0.00069 0.00065 0.00058 0.00076 0.00117 0.00146 0.00255 0.00185 0.00095 0.00228 0.00132 0.00097 0.00064 0.00122 0.00187 0.00228 0.00108 0.00027 Ca Ar 37 0.00086 0.01632 0.00874 0.02469 0.0169 0.0169 0.01671 0.02055 0.01606 0.01843 0.03655 0.02582 0.00737 0.1148 0.00441 0.0055 0.00607 0.00515 0.00504 0.00713 0.0056 0.00621 0.01383 0.01765 0.05299 0.00255 0.01476 0.01533 0.00211 0.00698 0.00414 0.0072 0.02154 0.02316 0.01899 0.02877 Cl Ar 38 0.00002 0.0001 0 0.00006 0.00006 0.00002 0.00006 0.00003 0.00001 0 0 0 0.00181 0.00596 0.00544 0.01054 0.01471 0.02404 0.03669 0.03674 0.0278 0.02478 0.02397 0.02185 0.03802 0.00073 0.00102 0.00274 0.01117 0.0234 0.02185 0.04385 0.05718 0.05847 0.02793 0.00509 Ar± 39 0.00002 0.00007 0.00024 0.00077 0.00039 0.00046 0.00112 0.00121 0.00146 0.00004 0.00109 0.00126 0.00012 0.00007 0.00004 0.00018 0.00036 0.00034 0.0005 0.00061 0.00052 0.0004 0.00051 0.00046 0.0008 0.00008 0.00003 0 0.0001 0.00029 0.00044 0.00067 0.0007 0.00114 0.0003 0.00004 K Ar 39 0.00519 0.10804 0.2399 0.6778 0.58397 0.67112 0.77956 1.13885 0.98913 1.10254 2.17228 1.2926 0.11461 0.26901 0.19264 0.33635 0.45953 0.79862 1.29545 1.35928 1.0474 0.9256 0.87438 0.77669 1.31422 0.03263 0.04262 0.06992 0.31586 0.74461 0.71861 1.45015 1.81548 1.85815 0.98148 0.15505 k k k Ar Ar Ar 39 39 39 I Ar 40 0.03326 0.39031 0.83472 1.48142 1.26251 1.44695 1.66642 2.41873 2.1133 2.35011 4.63441 2.78615 2.19042 1.2605 0.7593 0.85657 1.10295 1.81046 2.82199 2.94287 2.28776 2.0918 2.11245 2.00971 3.42578 0.60364 0.34495 0.79787 1.01661 1.77359 1.61667 3.24071 4.14841 4.35321 2.2704 0.3752 Wt.=59.8 mg Wt.=63.5 mg Wt.=50.5 mg K Ar 40 0.00005 0.00101 0.00224 0.00634 0.00546 0.00627 0.00729 0.01065 0.00925 0.01031 0.02031 0.01209 0.00107 0.00252 0.0018 0.00314 0.0043 0.00747 0.01211 0.01271 0.00979 0.00865 0.00818 0.00726 0.01229 0.00027 0.00035 0.00057 0.0026 0.00612 0.0059 0.01192 0.01492 0.01527 0.00806 0.00127 R Ar 40 0.00369 0.2252 0.49487 1.40362 1.19777 1.38809 1.61561 2.3636 2.05914 2.29272 4.52013 2.69012 0.28958 0.56189 0.40041 0.69147 0.94423 1.62964 2.62413 2.7559 2.12265 1.87255 1.77343 1.58564 2.68593 0.06129 0.06707 0.13019 0.62957 1.49122 1.43051 2.88681 3.60634 3.69055 1.95685 0.30012 SANIDINE BIOITITE BIOTITE Ar± 40 0.00001 0.00053 0.00008 0.00135 0.0008 0.00051 0.00143 0.00052 0.00217 0.00188 0.00256 0.00285 0.0013 0.00005 0.0001 0.00033 0.00071 0.00102 0.00109 0.00144 0.00093 0.00123 0.00161 0.00119 0.00169 0.00031 0.00035 0.0002 0.00027 0.00071 0.00074 0.00203 0.00216 0.00217 0.00052 0.00011 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.0333 0.39132 0.83696 1.48776 1.26797 1.45323 1.67371 2.42938 2.12255 2.36042 4.65472 2.79823 2.19149 1.26302 0.7611 0.85971 1.10725 1.81793 2.8341 2.95558 2.29755 2.10045 2.12063 2.01697 3.43807 0.60391 0.34531 0.79845 1.01921 1.77971 1.62257 3.25263 4.16333 4.36848 2.27847 0.37647 DRS-91-82/28/DD57 DRS-91-92/29/DD58 DRS-91-98/30/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 800 900 950 800 900 1150 1100 1100 1100 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1000 1050 1200 1250 1300 1350 1400 1500 1000 1200 1250 1300 1350 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.007547±0.1% containing 56.4% Plateau date: 27.32±0.04 Ma on steps 7 to 11 date: 27.49±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007621±0.1% Plateau date: 27.06±0.06 Ma on steps 6 to 10 containing 83.4% date: 27.00±0.08 Ma Total-gas 40 J-value and its error: 0.007349±0.1% Plateau date: 27.36±0.06 Ma on steps 6 to 12 containing 83.5% date: 27.3±0.08 Ma Total-gas Appendix 1. Appendix 1 55 0.18 0.36 0.09 0.1 0.04 0.05 0.04 0.04 0.04 0.04 0.06 0.4 2.63 1 0.16 0.1 0.04 0.04 0.04 0.04 0.04 0.04 9.36 1.26 8.53 1.09 1.02 1.23 0.42 0.15 0.05 0.06 0.3 0.14 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

5.5 age 28.3 26.7 27 26.9 26.8 26.7 26.8 26.9 26.9 27.1 27.1 27.2 21.2 27.7 27.6 27.2 27.2 27 27 27 27.1 15.3 59.8 44.4 30 28.1 24.5 25 26 26.6 26.3 26.5 27.1 Apparent Ar 39 0.9 1.2 3.8 9.6 7.9 9.8 8 1 0.1 0.4 1.6 9.3 0.2 0.9 0.4 2.8 1.8 1.8 5.3 11.3 12.6 12.9 17.6 14.8 14.9 14 15.4 19.1 13.9 10.7 19.5 19.6 16.2 20.7 %

1.8 3.8 7 Rad yield 14.4 25.4 72.5 87.7 93.5 94.3 96 96.7 97 97.3 93.6 70.8 16.3 30.7 79.3 90.9 89.7 87.8 86.7 86.7 86 25.3 38.1 70 59.8 63.3 72.5 86.9 86.4 85 86.4 K/Ca 2.07336 4.0997 9.42153 3.12867 2.75329 6.38682 0 0.17397 0.53238 0.64538 1.10885 0.34838 0.11779 0.08106 0.07767 0.08551 0.08099 0.08015 12.68002 16.15137 25.42822 27.84012 28.48048 29.7589 30.58261 19.11651 36.87866 105.42839 125.36837 308.73926 152.08088 138.47576 143.40472 388.7 F 2.17 2 1.98 1.97 1.96 1.95 1.96 1.96 1.97 1.98 1.9 1.99 1.14 1.61 2.05 2.01 1.99 1.98 1.97 1.97 1.97 1.98 1.11 4.4 3.26 2.19 2.05 1.79 1.82 1.89 1.94 1.92 1.93 1.97 I Ar 36 0.00394 0.00219 0.00092 0.00083 0.00033 0.00035 0.0003 0.00025 0.0003 0.00023 0.00033 0.00026 0.0011 0.00106 0.0023 0.00145 0.00085 0.00074 0.00112 0.00136 0.0017 0.00132 0.00036 0.00087 0.00138 0.00074 0.00012 0.00016 0.00041 0.00056 0.00041 0.00042 0.0004 0.00046 Ar± 36 0 0.00001 0.00001 0.00002 0.00001 0.00001 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00002 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00002 0.00001 T Ar 36 0.00394 0.00219 0.00093 0.00084 0.00033 0.00035 0.00031 0.00025 0.00031 0.00023 0.00034 0.00027 0.0011 0.00107 0.00231 0.00146 0.00087 0.00076 0.00114 0.00138 0.00172 0.00134 0.00037 0.00087 0.00138 0.00075 0.00013 0.00015 0.00055 0.00097 0.00118 0.00111 0.00101 0.00125 Ca Ar 37 0.02147 0.01339 0.01937 0.03619 0.02332 0.01839 0.02161 0.02177 0.02837 0.02318 0.0209 0.01531 0.00152 0.00296 0 0.00391 0.00528 0.00163 0.00408 0.00495 0.00593 0.01673 0.01095 0.01853 0.00736 0.02779 0.05748 0.00005 0.49154 1.44204 2.74874 2.50206 2.191 2.82082 Cl Ar 38 0.0004 0.00018 0.00007 0.00017 0.00017 0.00013 0.0002 0.00018 0.00023 0.00014 0.00006 0.0001 0.00021 0.00115 0.00631 0.0342 0.05384 0.03908 0.04919 0.05597 0.06753 0.04713 0.00015 0.00049 0.00043 0.00309 0.00252 0.00377 0.02463 0.07392 0.11335 0.06097 0.07228 0.09657 Ar± 39 0.00007 0.00002 0.00041 0.00065 0.00035 0.00048 0.00045 0.00072 0.00027 0.00074 0.00044 0.00003 0.00001 0.00007 0.00005 0.00065 0.00071 0.00052 0.00067 0.00085 0.00074 0.00033 0.00001 0 0.00001 0.00001 0.00001 0.00003 0.00016 0.00026 0.00043 0.00045 0.00021 0.00038 K Ar 39 k 0.08903 0.10979 0.36499 0.91778 0.7533 0.93525 1.20325 1.24004 1.68852 1.41781 0.79907 0.0958 0.00837 0.03781 0.14589 0.82445 1.32389 1.00649 1.24098 1.37091 1.70078 1.23396 0.00381 0.01973 0.0095 0.06163 0.04005 0.03887 0.1158 0.23379 0.427 0.42789 0.35489 0.4522 k Ar k Ar 39 39 Ar I 39 Ar 40 1.34713 0.86113 0.99137 2.05017 1.57063 1.92853 2.44414 2.50595 3.40947 2.87114 1.61622 0.26786 0.32764 0.37303 0.97485 2.08594 2.87849 2.21485 2.77071 3.09803 3.84986 2.82733 0.1115 0.34342 0.43933 0.35369 0.11701 0.11564 0.33219 0.60889 0.94892 0.94549 0.80438 1.02946 Wt.=53.5 mg Wt.=52.7 mg Wt.=187 mg K Ar 40 0.00083 0.00103 0.00341 0.00858 0.00704 0.00874 0.01125 0.01159 0.01279 0.01326 0.00716 0.0009 0.00007 0.00031 0.0012 0.00677 0.01088 0.00827 0.0102 0.01126 0.01397 0.01014 0.00003 0.00016 0.00008 0.00051 0.00033 0.00032 0.00095 0.00192 0.0035 0.00351 0.00291 0.00371 R Ar 40 0.19361 0.21927 0.72145 1.80612 1.47529 1.82724 2.35588 2.43404 3.31883 2.80516 1.51952 0.19089 0.00954 0.06087 0.29963 1.66114 2.62815 1.99537 2.44184 2.69694 3.35107 2.44046 0.00422 0.08685 0.03094 0.13492 0.08212 0.06939 0.21083 0.44282 0.82729 0.82036 0.68626 0.89239 SANIDINE BIOTITE AMPHIBOLE Ar± 40 0.00028 0.0003 0.0006 0.00129 0.00071 0.00065 0.00139 0.00102 0.00012 0.00123 0.0007 0.00005 0.0005 0.00081 0.00027 0.00125 0.00089 0.00108 0.00139 0.00134 0.00192 0.00074 0.00007 0.00037 0.0004 0.00005 0.00007 0.00007 0.0004 0.00062 0.00066 0.00089 0.00027 0.00074 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 1.34796 0.86216 0.99478 2.05875 1.57767 1.93727 2.45539 2.51754 3.42226 2.8844 1.62338 0.26876 0.32771 0.37334 0.97605 2.09271 2.88937 2.22312 2.7809 3.10929 3.86384 2.83747 0.11153 0.34358 0.43941 0.35419 0.11734 0.11596 0.33314 0.61081 0.95242 0.949 0.80729 1.03317 DRS-91-98/31/DD58 DRS-91-171/33/DD58 DRS-91-171/34/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 800 900 900 1100 1100 1100 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 1000 1200 1250 1300 1350 1400 1500 1000 1200 1250 1275 1300 1325 1375 1400 1450 1550 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007653±0.1% date: 26.76±0.05 Ma on steps 5 to 7 containing 30.2% Preferred date: 26.91±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.007671±0.1% Plateau date: 27.1±0.04 Ma on steps 7 to 10 containing 62.4% date: 27.07±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.00766±0.1% date: 26.91±0.34 Ma on steps 6 to 12 containing 78.1% Preferred date: 26.92±0.26 Ma Total-gas Appendix 1. 56 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.11 0.44 0.47 0.08 0.1 0.07 0.13 0.06 0.05 0.05 0.05 0.05 3.22 0.39 0.24 0.05 0.05 0.07 0.05 0.07 0.05 0.05 0.05 0.17 0.88 0.11 0.04 0.07 0.06 0.04 0.04 0.04 0.04 0.04 0.11 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 14.4 20.2 28.5 32.2 32.6 33.3 32.9 33 32.9 32.8 32.7 32.7 24.6 33.2 33.1 33.3 33.1 33.1 32.8 32.8 33.1 33 33.2 35.4 22.8 26.9 26.9 26.8 26.8 26.8 26.8 26.9 26.9 26.9 26.7 Apparent Ar 0.3 0.3 0.7 3.6 5 6.3 5.5 5.6 9.1 0.2 1.4 3.4 6.5 6.3 6.6 7.6 9.2 2.6 39 0.6 3.7 7 9.7 8.8 2.7 11.9 22.8 25.3 15.6 10.1 19.3 26.8 10.9 14.8 14.9 15.1 %

6.93 Rad 15.01 26.92 44.17 76.66 83.53 93.2 93.9 93.64 95.66 96.38 95.06 22.43 51.62 68.84 93.73 93.28 93.82 93.32 92.75 92.74 94.49 95.15 88.71 14 47.5 90.1 92.8 93.2 94.7 94.9 95.2 94.6 93.1 80.4 yield K/Ca 5.51205 3.41957 2.39261 6.52045 11.77278 28.27027 50.51852 33.97467 82.77413 72.01351 92.56371 62.80389 63.10247 43.29936 18.55978 10.83493 16.40239 20.88377 25.30239 22.84941 23.24685 22.84094 25.85714 14.42009 10.7918 13.15272 19.0133 25.03024 34.25119 37.83031 30.7736 31.9766 33.30966 25.08377 118.26142 F 1.1 1.54 2.18 2.47 2.5 2.55 2.52 2.53 2.52 2.51 2.5 2.5 1.87 2.53 2.52 2.53 2.52 2.52 2.5 2.5 2.52 2.51 2.53 2.7 1.75 1.98 1.96 1.96 1.96 1.96 1.95 1.96 1.96 1.96 1.95 I Ar 36 0.00105 0.00081 0.0011 0.00325 0.00109 0.00089 0.00027 0.00025 0.00042 0.00069 0.00062 0.00054 0.00034 0.00095 0.0011 0.00029 0.0003 0.00029 0.00036 0.00049 0.00054 0.00075 0.00091 0.00024 0.00232 0.00291 0.00052 0.00057 0.00047 0.00054 0.00052 0.00049 0.00045 0.00044 0.00046 Ar± 36 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0 0 0.00001 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 T Ar 36 0.00105 0.00081 0.0011 0.00325 0.00109 0.00089 0.00028 0.00026 0.00043 0.0007 0.00064 0.00056 0.00034 0.00096 0.0011 0.0003 0.00031 0.0003 0.00037 0.00049 0.00054 0.00076 0.00092 0.00025 0.00232 0.00292 0.00053 0.00058 0.00048 0.00054 0.00052 0.0005 0.00045 0.00044 0.00046 Ca Ar 37 0.00037 0.00027 0.00498 0.00454 0.00259 0.0037 0.00197 0.00259 0.00617 0.01537 0.02482 0.0358 0.0023 0.02491 0.02201 0.02508 0.01593 0.01325 0.01255 0.0169 0.01823 0.03527 0.04326 0.00911 0.00219 0.01818 0.02832 0.03045 0.02067 0.02307 0.02095 0.02617 0.01987 0.01408 0.00573 Cl Ar 38 0.00036 0.00056 0.00152 0.00941 0.01306 0.01617 0.01415 0.01458 0.02369 0.05853 0.0652 0.04167 0.0001 0.00018 0 0 0.00003 0 0 0 0.00004 0.00001 0 0.00005 0.00008 0.00018 0.00017 0.00017 0.00017 0.00027 0.00023 0.00023 0.00012 0.00006 0.00001 Ar± 39 0.00004 0 0.00009 0.00019 0.00039 0.00008 0.00024 0.00027 0.00029 0.00191 0.0017 0.00021 0.00002 0.00004 0.0003 0.0002 0.00047 0.00007 0.0001 0.00019 0.00036 0.00081 0.00119 0.00012 0.00007 0.00019 0.00031 0.00064 0.0006 0.00115 0.00079 0.00056 0.00055 0.00056 0.00003 K Ar 39 0.02092 0.02728 0.0549 0.30849 0.42877 0.5329 0.46595 0.47948 0.775 1.93977 2.14938 1.32888 0.01573 0.1192 0.28703 0.54348 0.52258 0.55342 0.63509 0.77231 0.84758 1.6112 2.23716 0.2145 0.06316 0.39239 0.74497 1.15791 1.03475 1.58035 1.58509 1.61069 1.27075 0.938 0.28746 k k k Ar Ar Ar 39 39 I 39 Ar 40 0.33232 0.28014 0.44477 1.72052 1.39276 1.62104 1.25525 1.28484 2.07947 5.07434 5.56362 3.4855 0.13071 0.58335 1.04658 1.4639 1.4085 1.48096 1.69553 2.07169 2.29238 4.27255 5.92334 0.65068 0.79056 1.63156 1.61534 2.43353 2.16123 3.24757 3.24908 3.30512 2.62562 1.9718 0.69483 Wt.=57.5 mg Wt.=59 mg Wt.=54.9 mg K Ar 40 0.0002 0.00026 0.00051 0.00288 0.00401 0.00498 0.00436 0.00448 0.00725 0.01814 0.0201 0.01243 0.00015 0.00111 0.00268 0.00508 0.00489 0.00517 0.00594 0.00722 0.00792 0.01506 0.02092 0.00201 0.00059 0.00367 0.00697 0.01083 0.00967 0.01478 0.01482 0.01506 0.01188 0.00877 0.00269 R Ar 40 0.02303 0.04209 0.11989 0.76127 1.07081 1.35815 1.17401 1.2107 1.95405 4.8717 5.3815 3.32526 0.02935 0.30167 0.72236 1.37686 1.31841 1.39436 1.58774 1.92819 2.13332 4.05117 5.65584 0.57898 0.11057 0.7773 1.46224 2.26728 2.02358 3.09033 3.09769 3.16056 2.49495 1.84311 0.56054 SANIDINE BIOTITE SANIDINE Ar± 40 0.00018 0.00008 0.00043 0.00077 0.00113 0.00029 0.00059 0.00028 0.00249 0.00544 0.00432 0.00095 0.00001 0.00045 0.00124 0.00113 0.00111 0.00096 0.00043 0.00082 0.00013 0.00222 0.00349 0.00005 0.00028 0.00107 0.00087 0.00143 0.00114 0.0022 0.00161 0.00109 0.00109 0.00139 0.00009 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.33251 0.28039 0.44528 1.7234 1.39677 1.62602 1.25961 1.28933 2.08672 5.09248 5.58371 3.49792 0.13085 0.58447 1.04927 1.46899 1.41339 1.48614 1.70146 2.07891 2.3003 4.28762 5.94425 0.65268 0.79115 1.63523 1.62231 2.44436 2.1709 3.26235 3.2639 3.32018 2.6375 1.98057 0.69752 DRS-91-171/32/DD58 DRS-92-1/38/DD57 DRS-92-1/37/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 900 800 900 900 1100 1100 1150 1100 1000 1200 1250 1300 1350 1400 1450 1500 1600 1000 1200 1250 1300 1350 1400 1450 1600 1000 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ Ar/ Ar/ TEMP ºC Sample: Sample: Sample: 40 J-value and its error: 0.0073±0.1% Plateau date: 32.74±0.05 Ma on steps 10 to 12 containing 63.7% date: 32.65±0.06 Ma Total-gas Sample: 40 J-value and its error: 0.007348±0.1% date: 32.81±0.06 Ma on steps 7 to 8 containing 16.8% Preferred date: 33.12±0.07 Ma Total-gas 40 J-value and its error: 0.007664±0.1% containing 95.7% Plateau date: 26.83±0.05 Ma on steps 3 to 11 date: 26.81±0.06 Ma Total-gas Appendix 1. Appendix 1 57 0.28 0.12 0.11 0.22 0.11 0.04 0.04 0.07 0.49 0.63 0.13 0.06 0.04 0.04 0.04 0.08 0.04 0.04 0.04 0.08 0.33 0.08 0.04 0.04 0.04 0.05 0.05 0.07 0.04 0.05 0.06 0.04 0.09 0.05 0.06 0.04 0.04 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 24.78 25.92 28 27.97 28.7 27.71 27.13 27.04 25.58 27.6 27.8 26.6 26.5 26.5 26.6 26.7 26.8 26.8 27.1 27.6 28.9 27.8 27.1 26.9 26.8 26.8 26.7 26.7 26.7 26.7 26.7 26.7 26.8 26.7 26.8 26.8 27 Apparent Ar 39 2.93 3.97 2.23 0.7 4.9 5.1 9.5 6.4 9.2 9.4 4.3 0.3 2.2 3.5 4.5 6 6.3 5.7 6 5.8 5.8 5.8 5.7 5.9 6.8 7.8 11.17 11.15 11.7 % 12.7 17.77 25.81 12.26 13.7 20.4 16.5 10.2

7.1 Rad 13.14 20.03 46.94 39.9 53.81 71.72 92.43 94.67 80.61 28 63 85.1 89.8 89 91.2 93.7 94.9 95.7 94.9 85.1 72.3 89.1 76.1 96.1 96.7 96.4 95.7 94.9 94.7 95.3 95.7 95.5 92.3 89.3 88.2 90 yield K/Ca 9.78974 5.36923 10.3657 24.1155 21.6532 26.25898 40.89737 58.0751 27.03478 16.01832 14.36053 13.76571 16.37299 22.53569 29.77158 34.53818 37.45263 31.74418 40.6609 29.53947 48.10572 94.48324 113.5848 113.33165 136.56787 178.76512 144.79635 306.8736 167.02181 655.01948 343.02326 202.09817 174.98362 F 1.89 1.98 2.14 2.14 2.2 2.12 2.08 2.07 1.96 2.11 2.1 2 1.99 1.99 2 2.01 2.01 2.01 2.03 2.07 2.37 2.08 2.02 2 1.99 1.99 1.98 1.98 1.98 1.99 1.98 1.98 1.99 1.99 1.99 2 2 I Ar 36 0.00542 0.00465 0.00399 0.00531 0.00353 0.00217 0.00061 0.00019 0.00015 0.0011 0.0018 0.00053 0.00063 0.00046 0.00052 0.00036 0.00042 0.00051 0.00051 0.00046 0.00549 0.00103 0.00049 0.00161 0.00026 0.00022 0.00022 0.00028 0.00033 0.00035 0.00031 0.00027 0.0003 0.00063 0.00106 0.00155 0.00147 Ar± 36 0.00001 0.00001 0.00001 0.00003 0.00002 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0 0 0 0.00002 0.00001 0.00001 0 0.00001 0.00001 0.00001 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00002 0.00001 0.00001 T Ar 36 0.00543 0.00465 0.004 0.00531 0.00354 0.00218 0.00063 0.0002 0.00016 0.0011 0.00181 0.00054 0.00064 0.00046 0.00052 0.00036 0.00042 0.00052 0.00052 0.00046 0.0045 0.00103 0.00049 0.00162 0.00026 0.00022 0.00022 0.00028 0.00033 0.00035 0.00031 0.00027 0.0003 0.00063 0.00106 0.00155 0.00148 Ca Ar 37 0.00618 0.00887 0.01013 0.01126 0.01058 0.0095 0.00972 0.00992 0.0091 0.00191 0.0152 0.01671 0.02614 0.01275 0.0139 0.01218 0.01636 0.02877 0.01821 0.00646 0 0.00402 0.00221 0.00215 0.00356 0.00178 0 0.00454 0.00298 0 0.00077 0 0.00537 0.00172 0.00594 0.00438 0.0058 Cl Ar 38 0.00383 0.00629 0.01907 0.01792 0.02124 0.03081 0.04638 0.02077 0.00379 0.00019 0 0.00007 0.00015 0.0001 0.00013 0.00015 0.00016 0.00021 0.00011 0.00005 0.00035 0.00011 0.00002 0.00014 0.0001 0.00012 0.00008 0.00017 0.00011 0.00012 0.00011 0.0001 0.00011 0.00011 0.00022 0.00034 0.00043 Ar± 39 0.00013 0.00001 0.00033 0.00024 0.00019 0.00068 0.00089 0.00028 0.00007 0.00004 0.0002 0.00004 0.00069 0.00022 0.00039 0.00058 0.00066 0.00035 0.00075 0.0001 0.00006 0.00011 0.00041 0.00039 0.00056 0.00072 0.00049 0.00063 0.00047 0.0005 0.00032 0.00031 0.00049 0.00059 0.00061 0.00074 0.00184 K Ar 39 0.12812 0.17367 0.48858 0.48763 0.55564 0.77705 1.12898 0.53637 0.09772 0.06119 0.43656 0.46005 0.85598 0.57466 0.82765 0.84135 1.22545 1.82656 1.48087 0.38165 0.05781 0.38677 0.60363 0.76869 1.03095 1.09247 0.98447 1.03135 0.99545 0.99749 1.00873 0.9877 1.01475 1.18 1.34638 1.77038 2.02981 k k k Ar Ar Ar 39 39 39 I Ar 40 1.84519 1.71723 2.22554 2.61152 2.26338 2.29022 2.52437 1.16708 0.23624 0.45176 1.44588 1.0745 1.88497 1.27914 1.80532 1.79548 2.58347 3.82423 3.16033 0.92459 1.74786 1.10414 1.35932 2.01185 2.12719 2.24034 2.01722 2.12705 2.07166 2.08388 2.09229 2.0392 2.10736 2.5301 2.99354 3.98756 4.50105 Wt.=25.6 mg Wt.=48.9 mg Wt.=60.9 mg K Ar 40 0.0012 0.00162 0.00457 0.00456 0.0052 0.00727 0.01056 0.00502 0.00091 0.0005 0.00359 0.00378 0.00703 0.00472 0.0068 0.00691 0.01007 0.01501 0.01217 0.00314 0.00054 0.00362 0.00564 0.00719 0.00964 0.01021 0.0092 0.00964 0.00931 0.00933 0.00943 0.00924 0.00949 0.01103 0.01259 0.01655 0.01898 R Ar 40 0.2427 0.34434 1.04681 1.04376 1.22063 1.64769 2.34314 1.10958 0.19117 0.12935 0.91637 0.91789 1.69974 1.1433 1.65203 1.68897 2.46037 3.67331 3.00908 0.79012 0.13715 0.80284 1.21673 1.53859 2.0534 2.17503 1.95278 2.04483 1.97423 1.98177 2.00226 1.95881 2.02018 2.34607 2.68413 3.53372 4.06908 BIOTITE SANIDINE ORTHOCLASE Ar± 40 0.00163 0.00119 0.00109 0.00187 0.0013 0.0017 0.00155 0.00075 0.00002 0.00032 0.00095 0.00025 0.0015 0.00034 0.00087 0.00146 0.00116 0.00087 0.00168 0.00027 0.00157 0 0.00085 0.00104 0.00114 0.00105 0.00111 0.00108 0.00107 0.00115 0.00104 0.00103 0.00125 0.00128 0.00076 0.00188 0.0034 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 1.84638 1.71886 2.23011 2.61608 2.26857 2.29749 2.53492 1.17209 0.23716 0.45226 1.44946 1.07828 1.89201 1.28386 1.81212 1.80239 2.59354 3.83924 3.17249 0.92773 1.7484 1.10776 1.36496 2.01904 2.13683 2.25055 2.02642 2.13669 2.08097 2.09321 2.10172 2.04844 2.11685 2.54113 3.00613 4.00411 4.52003 DRS-92-16/39/DD57 DRS-92-16/62/DD58 DRS-91-58A/40/DD58 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 36 850 900 800 900 950 1100 1100 1150 1150 1000 1250 1300 1350 1400 1450 1600 1000 1200 1250 1300 1350 1400 1450 1500 1600 1000 1050 1200 1250 1300 1350 1400 1450 1500 1550 1600 1700 Ar/ Ar/ Ar/ TEMP ºC 40 J-value and its error: 0.007527±0.1% Plateau date: 26.75±0.05 Ma on steps 5 to 16 containing 77.8% date: 26.82±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007300±0.1% Plateau date: 27.29±0.05 Ma on steps: 6 to 8 containing 55.84% date: 27.46±0.10 Ma Total-gas Sample: 40 J-value and its error: 0.007454±0.1% date: 26.67±0.05 Ma on steps 3 to 9 containing 73.7% Preferred date: 26.83±0.05 Ma Total-gas Sample: Appendix 1. 58 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 0.16 0.03 0.09 0.07 0.08 0.04 0.04 0.09 0.04 0.04 0.04 0.04 0.21 1.35 0.47 2.14 4.07 1.25 0.44 1.22 0.12 0.04 0.34 0.08 0.11 0.48 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 11.1 16.9 22.2 25.6 26.4 26.4 26.4 26.2 26.3 26.4 26.1 25.9 21.5 24.3 28.4 26.1 24.5 23.6 25.1 24.7 25.6 25.7 25.7 25.8 25.9 26 Apparent Ar 39 1 5.6 5.9 5.3 4.6 4.6 4.9 5.7 9.5 3.8 1.3 1.1 0.7 0.6 0.5 3.7 1.4 5.8 2.7 11.4 12.8 17.4 22.8 15.3 38.6 13.2 %

8 Rad 24.5 24.5 39.7 51.5 62.7 63.2 64.2 65.3 66.5 77.1 85.1 32 14.2 13.4 18.4 16.1 16.5 45.3 58.3 83.2 86 75.1 79 67.7 45.8 yield K/Ca 1.69651 1.24297 0.6765 0.62922 0.51801 0.60745 0.12312 0.09508 0.08832 0.0885 0.08834 0.08458 0.08494 0.08554 12.51351 26.6869 25.56087 28.23204 29.28369 31.83488 56.19231 65.94689 39.41566 41.05635 21.13274 16.74435 F 0.92 1.3 1.71 1.95 2 2 2 1.99 1.99 2 1.97 1.95 1.66 1.88 2.2 2.02 1.9 1.83 1.94 1.91 1.99 1.99 1.99 2 2.01 2.01 I Ar 36 0.00335 0.00684 0.0095 0.00483 0.00264 0.00165 0.00172 0.00191 0.00304 0.00388 0.00306 0.00231 0.00112 0.00119 0.00124 0.0005 0.00049 0.0004 0.00073 0.00015 0.0005 0.00101 0.00062 0.00057 0.00046 0.00053 Ar± 36 0 0 0.00002 0.00001 0.00001 0 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00002 0.00001 0.00001 0.00002 0 0 0.00001 T Ar 36 0.00335 0.00685 0.00951 0.00484 0.00265 0.00166 0.00173 0.00192 0.00306 0.0039 0.00309 0.00236 0.00112 0.0012 0.00125 0.0005 0.00049 0.00041 0.00083 0.0002 0.0011 0.00251 0.00106 0.00111 0.00069 0.00064 Ca Ar 37 0.0037 0.00939 0.01035 0.00849 0.00705 0.00645 0.0039 0.00386 0.01079 0.01393 0.03684 0.06106 0.02748 0.01245 0.01915 0.01304 0.01416 0.01061 0.37309 0.17501 2.12585 5.35426 1.58434 1.91248 0.83615 0.38705 Cl Ar 38 0.00309 0.01683 0.01912 0.01781 0.01542 0.01513 0.01605 0.01857 0.03107 0.0418 0.05679 0.074 0.00331 0.00119 0.00134 0.00105 0.00118 0.00117 0.0159 0.00664 0.07459 0.16363 0.04143 0.05642 0.02584 0.01165 Ar± 39 0.00006 0.0001 0.00029 0.00023 0.0001 0.00018 0.00013 0.00017 0.00061 0.00031 0.00144 0.00109 0.00009 0.00001 0.00002 0.00001 0.00002 0.00022 0.00009 0.00008 0.00026 0.00079 0.00109 0 0.00016 0.0001 K Ar 39 k 0.0926 0.50118 0.52911 0.47938 0.4129 0.41067 0.4383 0.50911 0.85059 1.14383 1.55706 2.04482 0.09324 0.03095 0.02591 0.01641 0.01467 0.01289 0.09187 0.03328 0.3755 0.94768 0.27991 0.32352 0.14205 0.06622 k Ar 39 Ar 39 I Ar 40 1.06619 2.65924 3.69253 2.35077 1.60177 1.30295 1.38008 1.57201 2.5878 3.42334 3.96736 4.67812 0.48493 0.41108 0.42441 0.17998 0.17279 0.14255 0.39327 0.10877 0.89258 2.18511 0.73801 0.8151 0.42022 0.29092 Wt.=60.9 mg Wt.=215 mg K Ar 40 0.00076 0.00412 0.00435 0.00394 0.00339 0.00337 0.0036 0.00418 0.00699 0.0094 0.01279 0.0168 0.00087 0.00029 0.00024 0.00015 0.00014 0.00012 0.00086 0.00031 0.00351 0.00886 0.00262 0.00302 0.00133 0.00062 R Ar 40 0.08514 0.65339 0.90639 0.93558 0.82725 0.81943 0.8745 1.01122 1.69554 2.28406 3.06993 3.99739 0.15519 0.05819 0.05703 0.03317 0.02787 0.02355 0.1785 0.06354 0.74557 1.88767 0.55602 0.64635 0.28522 0.13341 BIOTITE AMPHIBOLE Ar± 40 0.00047 0.00034 0.00264 0.00128 0.00058 0.00059 0.00049 0.00056 0.00158 0.00143 0.00354 0.00267 0.00048 0.00038 0.00039 0.00021 0.00019 0.00368 0.00034 0.00205 0.00014 0.00126 0.00003 0.00275 0.00003 0.00033 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 1.06695 2.66336 3.69688 2.3547 1.60516 1.30632 1.38369 1.57619 2.59478 3.43274 3.98015 4.69492 0.4858 0.41137 0.42465 0.18014 0.17293 0.14267 0.39413 0.10908 0.89609 2.19397 0.74063 0.81813 0.42154 0.29154 DRS-92-59/42/DD58 DRS-92-59/60/DD57 Ar measured atmosphere: 298.9 Ar measured atmosphere: 298.9 36 36 800 900 900 1100 1150 1100 1150 1000 1050 1200 1250 1300 1350 1400 1500 1000 1200 1250 1350 1400 1450 1475 1500 1550 1600 1650 Ar/ Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007422±0.1% date: 26.35±0.06 Ma on steps 5 to 10 containing 42.0% Preferred date: 25.24±0.05 Ma Total-gas Sample: 40 J-value and its error: 0.007209±0.1% Plateau date: 25.73±0.15 Ma on steps 9 to 14 containing 87.0% date: 25.53±0.21 Ma Total-gas Appendix 1. Appendix 1 59 1.5 0.14 1.79 0.22 0.49 0.24 0.04 0.08 0.06 0.04 0.04 0.04 0.06 0.09 0.12 0.39 Error ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

age 26.7 24.1 24.4 25.7 25.7 25.9 25.3 25.3 25.5 25.6 25.6 25.5 25.6 25.6 25.7 24.6 Apparent Ar 0.2 0.2 0.6 0.3 1 1.2 1.2 4.9 7.1 9.6 4.9 1.3 39 10 17.6 12.6 14.6 12.6 %

8.8 76.4 79.2 77.3 37.8 89.4 93.4 95.7 96.7 97.7 98.4 98.5 98.4 98.4 98.2 97.6 83.5 Rad yield K/Ca 2.79365 3.05409 7.4656 3.28429 6.84106 11.58254 20.42013 28.48308 27.69621 33.86795 49.20534 45.45083 49.63155 63.27054 63.62406 34.74765 13.06725 F 1.45 2 1.81 1.83 1.94 1.92 1.94 1.89 1.89 1.91 1.91 1.91 1.91 1.91 1.91 1.92 1.84 I Ar 36 0.00125 0.00005 0.0001 0.00005 0.00112 0.0001 0.00005 0.00014 0.00015 0.00013 0.00015 0.0001 0.00012 0.0001 0.00009 0.00007 0.00016 Ar± 36 0 0.00001 0 0.00001 0.00001 0.00001 0.00001 0 0.00001 0.00001 0.00001 0.00001 0.00001 0.00002 0.00002 0.00001 0.00001 T Ar 36 0.00126 0.00005 0.0001 0.00005 0.00113 0.0001 0.00005 0.00014 0.00015 0.00014 0.00016 0.0001 0.00012 0.00011 0.0001 0.00007 0.00016 Ca Ar 37 0.00441 0.00416 0.00436 0.00452 0.00755 0.00313 0.00527 0.00916 0.01371 0.01579 0.01909 0.01505 0.01566 0.01059 0.00802 0.00745 0.00513 Cl Ar 38 0.00065 0.00049 0.00076 0.00024 0.00041 0.00019 0.00014 0.00016 0.00012 0.00017 0.00022 0.00021 0.00015 0.00008 0.00008 0.00012 0.00013 Ar± 39 0.00004 0.00001 0.00001 0.00002 0.00002 0.00011 0.00011 0.00019 0.00015 0.00063 0.00105 0.00021 0.00107 0.00088 0.00057 0.00024 0 K Ar 39 k 0.02464 0.02541 0.0651 0.02969 0.1033 0.12783 0.12208 0.52181 0.75943 1.06955 1.87866 1.36807 1.55446 1.34007 1.02053 0.51774 0.13407 Ar 39 I Ar 40 0.40632 0.06633 0.14759 0.06994 0.53013 0.27376 0.2521 1.02552 1.48084 2.08001 3.63718 2.64079 2.99887 2.59219 1.98066 1.01438 0.29399 Wt.=47.8 mg K Ar 40 0.00023 0.00024 0.00061 0.00028 0.00097 0.0012 0.00114 0.00488 0.0071 0.01 0.01757 0.01279 0.01453 0.01253 0.00954 0.00484 0.00125 R Ar 40 0.03575 0.05092 0.11756 0.05426 0.20086 0.24584 0.23658 0.98588 1.4377 2.04111 3.59291 2.61149 2.965 2.56191 1.95294 0.99457 0.24679 ORTHOCLASE Ar± 40 0.0023 0.00005 0.00001 0 0.00024 0.00016 0.00168 0.00018 0.00032 0.00128 0.00163 0.00009 0.00116 0.00152 0.00094 0.00015 0.00006 Ar Data for Mineral Separates from Tertiary Igneous Rocks, Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks, Southern Toquima Ar Data for Mineral Separates from Tertiary 39 Ar/ T 40 Ar

40 0.40655 0.06657 0.1482 0.07022 0.5311 0.27496 0.25324 1.0304 1.48794 2.09001 3.65475 2.65358 3.0134 2.60472 1.9902 1.01922 0.29524 DRS-92-59/41/DD58 Ar measured atmosphere: 298.9 36 700 850 900 950 1100 1150 1000 1050 1200 1250 1300 1350 1400 1450 1500 1550 1600 Ar/ TEMP ºC Sample: Sample: 40 J-value and its error: 0.007483±0.1% Plateau date: 25.59±0.05 Ma on steps 10 to 16 containing 82.2% date: 28.79±0.1 Ma Total-gas Appendix 1.

Appendix 2 61 Total 93.95 94.68 92.97 95.21 92.45 93.68 94.49 94.60 94.36 94.26 94.38 94.39 95.26 93.48 93.93 95.59 94.97 94.01 93.83 93.87 94.81 93.63 94.61 94.90 94.10 95.13 94.39 95.40 93.73 93.66 94.51 94.20 95.74 94.46 94.04 94.62 94.38 93.84 93.77 93.58 93.86 94.47 93.45 94.36 94.56 Cl 0.06 0.05 0.07 0.11 0.08 0.08 0.05 0.07 0.09 0.09 0.10 0.21 0.19 0.09 0.10 0.19 0.20 0.13 0.10 0.09 0.09 0.10 0.11 0.17 0.20 0.20 0.22 0.21 0.09 0.09 0.09 0.09 0.19 0.23 0.09 0.09 0.10 0.11 0.11 0.12 0.08 0.10 0.09 0.09 0.21 F 0.53 0.48 0.51 0.48 0.38 0.34 0.48 0.49 0.34 0.44 0.71 0.48 0.91 0.49 0.96 0.50 0.57 0.39 0.69 0.40 0.45 0.41 0.38 0.54 0.45 0.57 0.60 0.53 0.35 0.65 0.43 0.56 1.18 0.66 0.48 0.40 0.51 0.49 0.46 0.45 0.46 0.38 0.54 0.49 0.81 O 2 K 7.71 7.93 7.72 8.37 7.77 7.99 8.71 8.65 8.82 8.68 8.70 8.56 8.70 8.57 8.51 8.93 8.69 8.65 8.62 8.55 8.70 8.69 8.58 8.63 8.49 8.62 8.49 8.86 8.53 8.51 8.60 8.73 8.72 8.59 8.54 8.71 8.62 8.64 8.49 8.64 8.44 8.73 8.61 8.59 8.80 O 2 0.64 0.76 0.39 0.52 0.48 0.38 0.59 0.61 0.54 0.51 0.54 0.54 0.53 0.54 0.51 0.56 0.53 0.54 0.50 0.60 0.62 0.60 0.57 0.55 0.54 0.56 0.54 0.52 0.61 0.58 0.54 0.53 0.44 0.50 0.56 0.57 0.53 0.58 0.48 0.51 0.56 0.58 0.50 0.50 0.37 Na 0.06 0.02 0.19 0.04 0.05 0.14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.00 0.05 CaO MgO 11.07 11.08 11.78 11.36 11.58 11.20 11.44 11.38 11.50 13.11 13.16 10.99 10.66 10.00 13.99 13.97 13.83 14.08 13.70 12.01 13.84 13.60 13.49 13.63 14.08 14.04 13.84 13.97 12.08 14.09 14.11 14.28 14.08 12.00 13.82 14.10 14.22 14.23 13.73 13.81 14.18 14.47 13.78 13.86 12.12 0.17 0.19 0.26 0.27 0.31 0.29 0.31 0.36 0.37 0.37 0.40 0.46 0.45 0.35 0.40 0.43 0.44 0.37 0.40 0.33 0.36 0.32 0.33 0.43 0.44 0.45 0.45 0.48 0.31 0.34 0.33 0.32 0.40 0.44 0.33 0.32 0.32 0.27 0.37 0.37 0.29 0.30 0.37 0.40 0.40 MnO FeO 14.56 15.11 15.83 17.73 17.55 17.34 15.81 16.10 16.16 15.96 16.39 19.97 19.23 15.86 16.33 19.99 19.95 16.51 16.24 15.58 15.86 15.53 15.71 19.87 19.74 20.21 19.59 19.26 15.72 15.50 15.58 15.47 19.13 19.69 16.04 15.75 15.77 15.27 16.36 16.24 15.81 15.47 16.02 16.00 17.53 2 6.23 6.11 5.35 5.62 5.32 5.49 4.71 4.57 4.60 4.56 4.36 4.47 4.12 4.48 4.55 4.19 4.50 4.62 4.59 4.51 4.61 4.43 4.63 4.35 4.45 4.42 4.47 4.28 4.50 4.24 4.58 4.45 4.30 4.25 4.68 4.49 4.32 4.49 4.41 4.45 4.30 4.34 4.37 4.46 4.06 TiO 3 O 2 Al 14.50 14.81 13.96 14.04 13.93 13.44 14.10 13.56 13.51 13.28 13.34 13.78 12.72 13.36 13.31 12.87 13.09 13.62 13.58 13.74 14.24 13.77 14.23 13.27 13.39 13.23 13.01 12.66 13.54 13.41 13.42 13.47 13.06 12.77 13.78 13.77 13.80 13.44 13.28 12.96 13.59 13.77 13.10 13.56 12.22 2 SiO 36.62 36.29 37.91 37.20 36.09 38.34 35.97 36.44 36.26 36.50 36.46 35.10 36.83 36.12 36.07 36.41 35.92 35.88 35.81 36.19 36.06 36.15 36.29 35.77 35.43 35.72 35.93 36.79 36.15 36.55 36.87 36.74 36.84 36.16 35.95 36.57 36.44 36.56 36.29 36.23 36.36 36.51 36.31 36.64 38.38

Probe sample no. 06TA1 06TA2 06TB1 06TD1 06TD2 06TE1 168TA1 168TB1 168TB2 168TC1 168TC2 168TD1 168TD2 168TE1 168TE2 168TL1 168TL2 168TM1 168TM2 168TN1 168TN2 168TQ1 168TQ2 168TR1 168TR2 168TT2 168TU1 168TU2 168TV1 168TV2 169TA1 169TA2 169TAC1 169TAC2 169TC1 169TC2 169TG1 169TG2 169TJ1 169TJ2 169TK1 169TL1 169TP1 169TP2 169TT1 Unit Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 Appendix 2. 62 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Total 94.78 95.30 95.11 94.92 95.00 95.93 93.15 93.01 93.44 93.49 93.38 92.89 94.74 94.96 94.52 94.25 93.09 92.45 92.89 93.38 94.58 93.97 93.89 94.33 93.44 94.00 94.82 95.66 94.10 93.89 95.71 96.37 93.12 92.98 94.11 94.15 94.09 94.56 95.17 95.38 95.35 95.30 94.41 93.11 94.93 Cl 0.18 0.18 0.19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 F 0.83 0.53 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 K 8.67 8.78 8.68 8.85 8.98 8.81 8.55 8.62 8.60 8.71 8.65 8.54 8.87 8.90 8.83 8.71 8.38 8.27 8.37 8.41 8.73 8.58 8.43 8.60 8.51 8.69 8.73 8.93 8.71 8.69 8.56 8.61 8.60 8.14 8.29 8.17 8.87 8.91 9.01 8.89 9.13 9.09 8.73 8.20 8.77 O 2 0.47 0.49 0.49 0.20 0.16 0.30 0.27 0.27 0.28 0.33 0.16 0.18 0.11 0.16 0.18 0.24 0.13 0.14 0.20 0.17 0.16 0.20 0.22 0.12 0.19 0.17 0.08 0.09 0.32 0.36 0.28 0.26 0.34 0.22 0.26 0.34 0.34 0.25 0.24 0.18 0.25 0.31 0.39 0.25 0.43 Na 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 CaO MgO 11.80 11.96 11.08 11.28 11.34 11.49 11.36 11.50 11.92 11.78 12.34 12.29 12.01 14.08 14.09 14.00 14.28 14.21 13.48 13.49 12.09 12.31 12.56 12.48 13.84 13.67 14.09 14.13 12.16 12.13 14.79 14.55 12.00 12.29 13.68 13.61 14.06 14.03 14.32 14.02 14.91 14.78 15.51 13.53 15.53 0.45 0.44 0.46 0.39 0.38 0.26 0.26 0.22 0.24 0.26 0.30 0.26 0.34 0.33 0.19 0.22 0.28 0.20 0.32 0.37 0.37 0.33 0.37 0.30 0.26 0.20 0.33 0.37 0.16 0.20 0.29 0.44 0.16 0.18 0.22 0.23 0.29 0.25 0.33 0.43 0.25 0.27 0.17 0.18 0.11 MnO FeO 18.91 19.15 19.35 19.39 19.36 16.32 15.39 15.38 15.40 15.40 16.33 16.25 19.32 18.65 18.81 18.77 15.31 15.49 20.02 19.55 19.59 19.52 19.64 19.82 15.54 15.62 18.89 19.41 14.74 14.77 19.96 20.16 16.12 16.49 16.35 16.45 15.44 15.61 19.47 19.92 15.48 15.48 13.79 16.91 13.89 2 4.20 3.97 4.13 4.36 4.31 4.43 4.16 4.35 4.32 4.35 4.53 4.36 4.27 4.29 3.72 3.64 4.35 4.42 4.25 4.68 4.21 4.16 4.24 4.65 4.36 4.35 4.13 4.19 4.45 4.27 4.24 4.29 4.34 4.24 4.41 4.51 4.42 4.31 4.15 4.24 4.37 4.24 4.45 4.29 4.31 TiO 3 O 2 Al 12.05 12.40 12.63 13.16 13.21 14.47 13.93 13.79 13.65 13.59 13.89 13.88 12.76 13.06 13.48 13.45 13.75 13.50 13.67 13.49 13.42 13.27 13.33 13.39 13.98 13.95 12.67 13.15 13.66 13.60 12.99 12.85 13.99 14.17 14.03 13.82 13.24 13.78 12.40 12.99 13.03 13.00 13.60 13.75 13.64 2 SiO 37.06 37.34 36.81 36.77 36.65 37.27 36.50 36.39 36.68 36.64 36.06 35.93 36.98 37.27 36.74 36.73 37.04 36.76 34.98 35.43 36.77 36.43 36.29 35.94 36.51 36.89 37.81 37.38 37.27 37.45 37.40 37.47 35.89 35.91 36.51 36.60 37.19 37.42 37.65 36.94 37.93 38.13 37.79 36.01 38.25

Original sample no. DRS-91-169 DRS-91-169 DRS-91-169 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 Appendix 2. Appendix 2 63 Total 93.99 94.98 95.50 93.39 93.76 94.80 96.08 93.88 93.96 94.33 94.40 94.04 93.78 93.65 94.34 93.62 93.85 93.49 94.36 94.34 93.56 94.19 93.26 92.47 93.04 93.39 92.64 94.48 94.64 94.94 94.17 96.53 95.95 96.82 96.44 95.57 96.69 96.17 96.33 96.69 95.80 97.10 96.70 96.22 96.49 Cl 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.07 0.20 0.09 0.11 0.11 0.11 0.10 0.12 0.09 0.09 0.09 0.09 0.08 F 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.64 0.57 0.80 1.35 0.64 0.95 0.99 0.91 0.67 0.99 0.71 0.76 0.92 0.62 O 2 K 8.27 8.40 8.53 8.11 8.28 8.47 8.52 8.33 8.02 8.54 8.54 8.58 8.51 8.47 8.22 8.35 7.72 8.31 8.48 8.26 8.33 8.39 8.42 8.46 8.35 8.21 8.21 8.36 8.16 8.50 8.52 8.66 8.82 8.69 8.83 8.66 8.83 8.96 8.84 9.03 8.96 8.94 8.88 8.85 8.93 O 2 0.24 0.15 0.17 0.37 0.34 0.23 0.18 0.35 0.44 0.36 0.33 0.43 0.37 0.36 0.31 0.35 0.23 0.24 0.32 0.36 0.27 0.31 0.41 0.38 0.47 0.38 0.30 0.29 0.38 0.28 0.26 0.54 0.58 0.49 0.57 0.55 0.56 0.50 0.58 0.54 0.57 0.57 0.55 0.54 0.51 Na 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.08 0.01 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 CaO MgO 11.52 11.96 11.38 13.70 12.33 12.60 14.14 14.24 14.98 14.68 13.96 14.02 13.75 13.68 13.84 13.68 14.00 13.12 13.68 14.03 14.21 13.56 14.32 14.40 14.30 14.48 13.89 14.23 14.13 14.01 13.76 13.74 13.92 13.66 13.59 13.50 13.85 13.93 13.60 14.37 13.78 14.21 14.24 13.11 13.45 0.30 0.38 0.35 0.15 0.10 0.34 0.36 0.18 0.21 0.27 0.25 0.24 0.21 0.22 0.27 0.15 0.15 0.20 0.24 0.25 0.27 0.26 0.18 0.16 0.17 0.22 0.16 0.25 0.24 0.28 0.27 0.36 0.31 0.34 0.23 0.35 0.33 0.29 0.34 0.32 0.29 0.30 0.34 0.36 0.43 MnO FeO 16.96 19.40 19.74 15.63 15.50 20.46 20.62 15.08 15.32 16.44 16.03 16.49 15.57 16.25 16.27 15.96 17.13 16.32 16.24 16.01 16.25 16.18 14.96 14.74 14.94 15.84 15.21 16.20 16.56 16.83 16.46 16.10 16.15 19.37 15.87 16.06 16.27 15.84 16.31 15.60 16.00 16.05 15.92 17.00 16.79 2 4.42 4.12 4.21 4.35 4.36 4.37 4.32 4.42 4.39 4.43 4.07 4.36 4.58 4.38 4.40 4.38 3.88 4.12 4.38 4.28 4.76 4.10 4.39 4.44 4.10 4.52 4.37 4.48 4.28 4.59 4.03 4.64 4.69 4.18 4.70 4.77 4.47 4.44 4.76 4.56 4.61 4.68 4.72 4.75 4.68 TiO 3 O 2 Al 13.85 13.15 12.83 14.16 13.98 13.19 13.15 13.69 13.96 13.80 13.96 13.89 14.12 13.80 14.30 13.90 14.20 14.00 13.97 13.96 14.41 13.78 14.19 14.41 14.34 14.39 13.94 14.04 14.11 13.84 13.88 14.35 14.94 13.88 15.34 15.19 14.53 14.44 14.63 14.29 14.72 14.49 14.56 14.77 14.49 2 SiO 36.23 37.04 37.06 36.48 36.95 36.22 36.97 36.86 36.93 36.54 37.21 36.29 36.74 36.35 36.90 36.53 37.39 36.62 36.70 37.00 35.73 36.85 36.31 35.58 36.19 35.94 36.23 36.74 36.90 36.86 36.99 37.51 36.42 37.81 36.44 36.05 37.19 37.11 36.65 37.50 36.23 37.37 37.00 36.24 36.79

Original sample no. DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 Appendix 2. 64 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Total 96.24 96.85 96.09 96.76 95.94 96.19 96.39 95.11 96.35 96.87 96.81 96.59 96.58 96.15 97.26 96.59 97.58 97.63 96.46 95.36 94.58 95.68 97.67 94.46 97.26 97.17 96.77 97.38 95.66 96.63 95.76 96.59 97.46 97.63 95.80 96.91 96.70 96.21 96.82 96.19 96.97 97.77 96.83 96.02 97.59 Cl 0.09 0.09 0.11 0.11 0.11 0.09 0.12 0.13 0.11 0.09 0.09 0.11 0.10 0.10 0.09 0.12 0.10 0.07 0.10 0.13 0.10 0.11 0.12 0.13 0.11 0.10 0.12 0.10 0.15 0.11 0.15 0.17 0.12 0.10 0.11 0.09 0.10 0.12 0.09 0.10 0.08 0.09 0.11 0.10 0.12 F 0.83 1.05 0.61 0.56 0.70 0.87 1.07 0.90 0.62 0.87 0.62 0.92 0.88 0.67 0.86 4.73 4.57 5.51 3.76 4.69 3.52 4.40 5.25 4.64 3.77 4.19 4.31 4.51 2.85 4.12 3.86 4.05 3.55 3.98 2.62 3.38 3.71 3.80 3.78 3.92 4.12 4.40 3.67 3.60 3.94 O 2 K 8.60 8.91 8.54 8.84 8.81 8.97 8.90 8.84 8.77 8.88 8.95 8.80 8.84 8.89 8.87 8.38 8.62 8.79 8.29 8.31 7.94 7.79 8.69 8.03 8.72 8.64 8.55 8.53 8.17 8.44 8.49 8.59 8.66 8.65 8.29 8.70 8.58 8.69 8.75 8.65 8.72 8.75 8.78 8.45 8.78 O 2 0.55 0.55 0.60 0.60 0.51 0.55 0.52 0.52 0.53 0.57 0.54 0.56 0.54 0.55 0.59 0.64 0.58 0.61 0.49 0.60 0.47 0.48 0.58 0.58 0.60 0.62 0.55 0.64 0.55 0.54 0.60 0.63 0.60 0.61 0.49 0.61 0.63 0.61 0.59 0.57 0.60 0.55 0.53 0.62 0.62 Na 0.08 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.04 0.04 0.00 0.00 0.00 0.00 0.01 0.03 0.00 0.06 0.06 0.00 0.55 0.00 0.00 0.00 0.05 0.01 0.01 0.00 0.03 0.00 0.01 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.02 0.00 0.01 0.02 CaO MgO 13.70 13.96 13.80 13.81 13.68 13.92 13.80 13.20 13.30 13.95 13.99 13.87 13.83 14.23 14.25 16.46 14.90 16.94 13.36 14.43 13.19 13.73 16.77 15.29 14.73 15.97 15.90 16.25 13.39 15.65 16.41 17.00 13.69 14.51 12.72 13.91 14.99 15.80 15.85 15.66 15.68 15.92 15.53 15.06 15.40 0.26 0.33 0.33 0.35 0.36 0.35 0.26 0.37 0.41 0.29 0.32 0.29 0.31 0.30 0.34 0.18 0.34 0.34 0.32 0.32 0.36 0.46 0.23 0.21 0.37 0.29 0.31 0.22 0.45 0.34 0.24 0.29 0.42 0.37 0.45 0.41 0.24 0.21 0.31 0.31 0.36 0.32 0.17 0.21 0.28 MnO FeO 11.81 11.72 11.39 15.74 16.21 16.04 16.35 16.04 15.54 16.25 16.56 16.90 16.32 16.08 15.97 16.01 15.45 16.02 14.83 16.72 14.15 16.32 16.78 12.05 12.41 15.23 13.40 13.09 12.21 16.22 13.27 10.83 16.27 14.60 16.77 15.57 13.85 12.88 12.46 12.28 13.08 12.97 12.73 13.32 13.26 2 4.50 4.86 4.46 5.01 4.77 4.56 4.73 4.58 4.70 4.55 4.69 4.49 4.46 4.72 4.56 5.09 4.35 4.38 4.25 4.50 4.34 4.22 4.45 4.37 4.43 4.55 4.51 4.38 4.69 4.57 4.87 4.69 4.55 4.52 4.71 4.47 4.65 4.53 4.57 4.60 4.17 4.31 4.86 4.95 4.67 TiO 3 O 2 Al 14.63 14.53 14.71 15.05 14.83 14.64 14.96 14.22 14.53 14.78 14.82 14.48 14.46 14.50 14.60 13.89 13.47 13.68 13.69 13.98 13.80 13.65 13.71 13.42 13.57 13.49 13.87 13.53 14.13 13.89 14.05 13.94 13.50 13.49 13.98 13.42 13.78 13.51 13.61 13.49 13.34 13.32 13.51 13.74 13.72 2 SiO 37.64 36.82 37.16 36.34 36.44 37.09 36.26 36.21 36.78 36.96 37.00 37.48 37.52 37.05 37.48 37.30 37.76 37.93 37.07 36.26 35.96 35.90 38.05 36.79 37.34 37.66 37.42 38.83 36.29 37.43 37.37 38.13 37.61 38.50 36.79 37.80 37.77 37.70 38.37 38.29 38.57 39.00 38.50 37.49 38.48

Original sample no. DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 Appendix 2. Appendix 2 65 Total 97.24 96.23 98.30 94.70 96.43 96.05 97.32 96.00 96.85 95.97 96.56 94.19 96.28 97.35 96.43 97.09 96.95 95.95 95.74 95.57 95.76 95.21 95.52 94.13 95.39 94.96 95.02 95.25 96.75 95.61 94.13 95.40 94.24 94.71 95.97 95.37 96.33 95.05 96.14 95.38 95.33 94.93 95.62 95.64 96.34 Cl 0.11 0.12 0.10 0.11 0.10 0.13 0.09 0.12 0.09 0.12 0.10 0.14 0.10 0.12 0.12 0.14 0.12 0.09 0.10 0.09 0.09 0.10 0.10 0.07 0.05 0.08 0.09 0.19 0.20 0.15 0.06 0.08 0.10 0.09 0.07 0.07 0.07 0.05 0.11 0.11 0.08 0.06 0.08 0.09 0.06 F 3.61 2.10 3.53 1.51 3.35 3.09 3.23 3.09 4.29 3.19 3.33 3.22 3.55 3.52 3.67 3.30 3.54 2.21 2.77 1.04 1.33 1.17 1.94 0.84 2.00 0.79 1.46 2.40 2.71 2.37 1.39 2.21 1.00 1.71 0.51 0.43 0.46 0.39 0.94 0.81 0.52 0.36 0.42 0.48 0.55 O 2 K 8.82 8.50 8.94 8.27 8.41 8.41 8.59 8.17 8.69 8.50 8.60 8.03 8.58 8.72 8.31 8.49 8.49 8.66 8.84 8.87 8.69 8.66 8.70 8.46 8.53 8.77 8.76 9.04 9.40 9.73 8.83 8.67 8.93 8.96 8.76 8.72 8.84 8.72 8.62 8.47 8.62 8.39 8.74 8.60 8.93 O 2 0.63 0.50 0.60 0.49 0.47 0.51 0.61 0.56 0.58 0.55 0.60 0.50 0.58 0.56 0.58 0.63 0.60 0.60 0.54 0.42 0.40 0.48 0.62 0.68 0.66 0.44 0.52 0.37 0.40 0.20 0.42 0.45 0.48 0.45 0.57 0.55 0.59 0.55 0.57 0.54 0.65 0.60 0.57 0.55 0.57 Na 0.00 0.00 0.00 0.03 0.03 0.02 0.00 0.01 0.02 0.06 0.01 0.05 0.02 0.02 0.05 0.00 0.01 0.03 0.03 0.03 0.06 0.04 0.01 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 CaO MgO 15.10 12.50 13.97 12.13 13.94 13.46 13.94 12.37 14.46 14.48 15.20 12.74 13.36 14.75 14.16 14.12 14.44 13.84 14.07 13.08 13.41 13.88 13.48 14.82 14.31 13.59 13.70 13.58 14.88 15.12 13.43 13.85 13.72 13.64 14.33 14.22 14.50 14.08 12.72 12.81 14.24 13.96 14.24 14.10 14.67 0.24 0.45 0.38 0.45 0.42 0.44 0.42 0.47 0.30 0.33 0.33 0.46 0.45 0.22 0.28 0.25 0.29 0.23 0.22 0.30 0.30 0.27 0.26 0.24 0.21 0.31 0.29 0.18 0.16 0.16 0.26 0.20 0.28 0.29 0.24 0.23 0.26 0.26 0.39 0.39 0.22 0.21 0.25 0.28 0.21 MnO FeO 13.51 17.50 15.94 17.21 15.19 15.22 15.78 16.95 13.95 14.30 13.28 15.79 15.56 13.90 14.50 14.71 14.23 15.11 14.87 16.32 15.88 15.91 16.58 14.13 14.49 16.00 15.74 15.83 14.06 13.84 15.44 15.58 15.48 15.47 15.28 15.34 15.44 15.27 17.34 16.98 15.17 15.61 15.39 15.62 15.21 2 4.83 4.66 4.67 4.76 4.69 4.91 4.55 4.91 4.62 4.59 4.70 4.62 4.38 4.68 4.55 5.18 5.03 4.52 4.37 4.65 4.47 4.48 4.41 4.68 4.53 4.56 4.55 4.66 4.60 4.48 4.42 4.31 4.57 4.51 5.00 5.02 4.94 4.89 5.74 5.69 5.10 4.90 5.00 4.97 4.90 TiO 3 O 2 Al 13.63 14.06 13.51 14.26 13.75 14.27 13.60 14.41 13.70 13.59 13.72 13.37 13.30 13.64 13.22 14.16 14.13 14.69 14.55 13.97 14.05 14.17 13.99 14.43 14.84 14.53 14.22 14.00 14.42 13.52 14.03 14.28 13.92 13.95 14.60 14.64 14.37 14.61 14.27 14.20 14.63 14.76 14.52 14.46 14.39 2 SiO 38.31 36.75 38.14 36.13 37.52 36.94 37.91 36.27 37.98 37.63 38.11 36.65 37.92 38.74 38.57 37.53 37.59 36.93 36.58 37.26 37.67 36.57 36.26 36.15 36.59 36.23 36.34 36.06 37.11 37.07 36.41 36.66 36.21 36.37 36.84 36.36 37.06 36.41 35.87 35.72 36.34 36.26 36.61 36.72 37.07

Original sample no. DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 Appendix 2. 66 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Total 95.45 95.45 95.64 95.03 95.47 94.36 95.94 95.38 94.64 95.85 96.19 95.97 95.37 96.33 95.05 96.14 95.38 95.33 94.93 95.62 95.64 96.34 95.45 95.45 95.64 95.03 95.47 94.36 95.94 95.38 94.64 95.85 96.19 97.24 96.85 96.24 96.87 97.05 95.86 95.21 97.14 96.66 96.14 96.41 95.32 Cl 0.06 0.07 0.05 0.06 0.06 0.08 0.08 0.08 0.08 0.05 0.08 0.07 0.07 0.07 0.05 0.11 0.11 0.08 0.06 0.08 0.09 0.06 0.06 0.07 0.05 0.06 0.06 0.08 0.08 0.08 0.08 0.05 0.08 0.08 0.08 0.10 0.12 0.12 0.12 0.12 0.10 0.10 0.10 0.10 0.19 F 0.50 0.77 0.44 0.39 0.43 0.41 0.48 0.69 0.69 0.41 0.47 0.51 0.43 0.46 0.39 0.94 0.81 0.52 0.36 0.42 0.48 0.55 0.50 0.77 0.44 0.39 0.43 0.41 0.48 0.69 0.69 0.41 0.47 1.07 0.40 0.56 0.74 1.22 1.11 1.24 1.15 0.82 0.74 0.76 0.66 O 2 K 8.60 8.46 8.69 8.37 8.54 8.52 8.70 8.37 8.58 8.73 8.65 8.76 8.72 8.84 8.72 8.62 8.47 8.62 8.39 8.74 8.60 8.93 8.60 8.46 8.69 8.37 8.54 8.52 8.70 8.37 8.58 8.73 8.65 8.88 8.87 8.37 9.15 9.01 8.28 8.02 8.94 8.77 8.56 8.68 8.81 O 2 0.60 0.59 0.67 0.63 0.68 0.57 0.61 0.61 0.57 0.58 0.59 0.57 0.55 0.59 0.55 0.57 0.54 0.65 0.60 0.57 0.55 0.57 0.60 0.59 0.67 0.63 0.68 0.57 0.61 0.61 0.57 0.58 0.59 0.63 0.67 0.69 0.50 0.48 0.42 0.42 0.47 0.47 0.49 0.47 0.50 Na 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.05 0.09 0.09 0.42 0.04 0.08 0.04 0.03 CaO 9.09 MgO 11.51 11.75 14.26 14.45 14.74 14.17 14.53 14.18 14.71 13.79 13.65 14.67 14.75 14.33 14.22 14.50 14.08 12.72 12.81 14.24 13.96 14.24 14.10 14.67 14.26 14.45 14.74 14.17 14.53 14.18 14.71 13.79 13.65 14.67 14.75 12.37 13.70 13.40 13.04 12.74 13.67 13.65 13.63 13.51 0.24 0.19 0.23 0.21 0.18 0.21 0.23 0.24 0.26 0.25 0.24 0.24 0.23 0.26 0.26 0.39 0.39 0.22 0.21 0.25 0.28 0.21 0.24 0.19 0.23 0.21 0.18 0.21 0.23 0.24 0.26 0.25 0.24 0.31 0.34 0.25 0.65 0.64 0.38 0.39 0.63 0.58 0.63 0.66 0.41 MnO FeO 15.40 14.96 14.51 15.04 14.88 14.91 15.02 16.14 15.81 15.22 15.03 15.28 15.34 15.44 15.27 17.34 16.98 15.17 15.61 15.39 15.62 15.21 15.40 14.96 14.51 15.04 14.88 14.91 15.02 16.14 15.81 15.22 15.03 20.09 18.32 22.82 17.32 17.00 17.10 17.37 16.89 16.94 16.88 17.09 19.23 2 5.00 5.31 5.12 5.34 5.15 5.04 4.89 5.15 5.01 4.98 5.19 5.00 5.02 4.94 4.89 5.74 5.69 5.10 4.90 5.00 4.97 4.90 5.00 5.31 5.12 5.34 5.15 5.04 4.89 5.15 5.01 4.98 5.19 5.57 5.22 5.15 3.97 3.99 4.85 4.77 4.12 4.21 3.93 4.09 4.26 TiO 3 O 2 Al 14.64 14.60 14.45 14.89 14.90 14.60 14.45 14.68 14.35 14.41 14.37 14.60 14.64 14.37 14.61 14.27 14.20 14.63 14.76 14.52 14.46 14.39 14.64 14.60 14.45 14.89 14.90 14.60 14.45 14.68 14.35 14.41 14.37 13.70 13.51 13.20 13.45 13.64 13.92 13.92 13.45 13.70 13.44 13.51 13.17 2 SiO 36.37 36.39 36.94 36.11 36.31 36.03 36.98 35.91 35.97 36.74 37.04 36.84 36.36 37.06 36.41 35.87 35.72 36.34 36.26 36.61 36.72 37.07 36.37 36.39 36.94 36.11 36.31 36.03 36.98 35.91 35.97 36.74 37.04 35.84 37.25 36.26 37.61 38.03 37.05 36.68 37.81 37.75 37.98 37.84 36.65

Original sample no. DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-89 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 DRS-92-20 Appendix 2. Appendix 2 67 Total 95.60 96.62 94.68 95.03 95.22 96.40 97.50 97.03 95.30 96.69 97.25 95.92 96.06 95.50 95.82 96.96 96.76 96.84 96.18 95.49 95.81 95.94 96.38 96.85 96.22 96.31 96.51 96.39 96.34 95.60 96.60 96.71 96.94 96.82 95.80 97.08 97.44 96.71 96.90 96.90 97.10 96.88 96.59 96.63 97.99 96.98 Cl 0.18 0.19 0.10 0.09 0.18 0.20 0.22 0.21 0.22 0.21 0.20 0.14 0.12 0.22 0.21 0.13 0.15 0.13 0.13 0.14 0.13 0.13 0.13 0.05 0.08 0.12 0.14 0.14 0.13 0.15 0.13 0.14 0.13 0.14 0.19 0.20 0.19 0.19 0.18 0.16 0.16 0.22 0.21 0.27 0.19 0.20 F 0.72 0.67 0.72 0.50 0.57 0.96 0.74 0.64 0.60 0.47 0.75 0.60 0.45 0.57 0.53 0.57 0.51 0.55 0.62 0.49 0.54 0.51 0.52 0.54 0.53 0.51 0.48 0.59 0.57 0.46 0.56 0.50 2.73 2.38 2.16 3.19 3.21 4.03 4.26 1.98 2.22 2.86 2.86 4.24 3.94 3.78 O 2 K 8.19 8.63 8.64 8.25 8.03 8.75 8.94 8.83 8.24 8.90 8.82 8.97 8.90 8.40 8.48 9.11 9.05 9.18 8.97 8.74 8.95 9.00 8.87 9.18 9.13 8.93 9.03 8.87 8.92 8.78 9.09 9.06 8.34 8.17 7.69 8.27 8.36 8.61 8.65 8.36 8.24 8.34 8.79 8.56 8.77 8.44 O 2 0.46 0.48 0.51 0.48 0.44 0.57 0.52 0.52 0.47 0.48 0.53 0.53 0.51 0.47 0.53 0.49 0.52 0.43 0.48 0.43 0.50 0.49 0.52 0.50 0.48 0.47 0.49 0.51 0.49 0.54 0.53 0.50 0.46 0.53 0.45 0.39 0.56 0.60 0.58 0.37 0.43 0.44 0.40 0.53 0.46 0.45 Na 0.19 0.06 0.03 0.15 0.24 0.07 0.00 0.03 0.12 0.01 0.00 0.01 0.00 0.06 0.09 0.00 0.03 0.00 0.00 0.00 0.00 0.01 0.03 0.00 0.00 0.00 0.00 0.01 0.02 0.02 0.03 0.00 0.04 0.02 0.00 0.02 0.00 0.00 0.00 0.01 0.00 0.08 0.04 0.06 0.04 0.04 CaO 8.69 8.60 8.81 MgO 11.85 11.49 11.54 11.42 11.67 11.07 11.24 11.25 11.21 11.42 12.45 13.12 13.65 12.04 12.01 12.03 13.19 13.46 13.92 14.05 13.99 13.61 13.39 13.71 13.94 13.99 13.91 13.63 13.72 13.75 13.64 13.91 13.23 13.49 13.47 10.26 10.33 13.11 13.48 13.35 13.27 13.63 12.82 0.36 0.47 0.36 0.35 0.39 0.44 0.47 0.41 0.41 0.50 0.42 0.36 0.43 0.44 0.39 0.20 0.16 0.18 0.21 0.13 0.23 0.20 0.21 0.18 0.22 0.21 0.20 0.20 0.19 0.14 0.25 0.21 0.17 0.14 0.17 0.12 0.21 0.08 0.12 0.20 0.16 0.15 0.13 0.13 0.09 0.18 MnO FeO 18.84 19.10 16.86 16.48 19.14 19.98 19.80 19.40 19.68 20.37 20.20 17.16 17.02 19.83 20.46 16.55 16.61 16.67 16.84 16.60 16.32 16.30 16.45 16.94 16.86 16.81 16.73 16.91 16.65 16.06 17.10 17.31 19.03 18.70 17.20 12.37 18.21 14.84 15.20 20.90 19.99 14.49 16.48 12.40 12.99 13.85 2 3.93 4.13 4.69 4.47 4.29 4.43 4.48 4.23 4.35 4.52 4.28 4.71 4.68 4.30 4.48 4.82 4.72 4.61 4.74 5.02 4.78 4.71 4.68 4.38 4.60 4.65 4.88 4.79 4.64 4.50 4.57 4.78 5.22 5.16 4.39 4.64 4.69 5.44 5.25 4.79 4.74 4.49 5.21 5.34 6.01 4.12 TiO 3 O 2 Al 13.30 13.03 14.30 14.21 13.41 13.55 13.66 13.64 13.65 14.10 13.53 14.36 14.29 14.07 13.99 13.69 13.61 13.81 14.09 13.70 13.61 13.41 13.47 14.60 14.31 14.00 14.14 13.95 13.97 13.57 13.82 13.83 15.53 16.24 17.97 17.50 15.44 14.84 14.76 15.76 16.23 17.27 15.61 16.10 16.03 16.11 2 SiO 37.93 37.74 35.67 36.61 36.76 36.39 37.01 37.42 36.33 35.96 37.22 36.17 36.42 36.34 35.68 37.76 37.60 37.55 36.77 37.06 37.31 37.49 37.75 36.82 36.63 37.11 36.88 37.07 37.12 38.38 37.29 37.15 36.21 36.06 37.83 38.67 36.73 36.32 36.40 36.64 37.10 38.56 36.70 37.60 37.52 38.61

Probe 920TAE1 920TAE2 920TE1 920TE2 920TF1 920TF2 920TG1 920TG2 920TN2 920TQ1 920TQ2 920TS1 920TS2 920TT1 920TT2 921T1 921T2 921TAC1 921TAC2 921TK1 921TK2 921TL1 921TL2 921TM1 921TM2 921TN1 921TN2 921TP1 921TP2 921TU1 921TV1 921TV2 959TA1 959TA2 959TD1 959TD2 959TG1 959TH1 959TH2 959TL1 959TL2 959TM1 959TM2 959TQ1 959TQ2 959TR1 sample no. Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff of Corcoran Canyon, lower Tuff Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Compositions (in Weight

Original sample no. DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 DRS-91-59 Appendix 2.

Appendix 3 69 97.86 98.70 96.71 99.21 96.37 97.59 98.48 98.58 98.39 98.25 98.23 98.32 99.02 97.40 97.62 99.57 98.88 97.99 97.68 97.87 98.82 97.62 98.65 98.82 98.03 99.06 98.25 99.35 97.73 97.54 98.53 98.11 99.38 98.30 98.00 98.61 98.35 97.80 97.71 97.50 97.84 98.49 97.35 98.34 98.31 TOTAL 0.24 0.21 0.23 0.23 0.18 0.16 0.21 0.22 0.16 0.21 0.32 0.25 0.43 0.23 0.43 0.25 0.29 0.19 0.31 0.19 0.21 0.20 0.18 0.27 0.23 0.29 0.30 0.27 0.17 0.29 0.20 0.26 0.54 0.33 0.22 0.19 0.24 0.23 0.22 0.22 0.21 0.18 0.25 0.23 0.39 O=F;Cl 98.10 98.91 96.94 99.44 96.54 97.75 98.69 98.80 98.56 98.45 98.55 98.57 99.44 97.62 98.05 99.82 99.17 98.18 98.00 98.06 99.03 97.81 98.83 99.09 98.27 99.34 98.55 99.62 97.90 97.84 98.73 98.37 99.92 98.63 98.22 98.80 98.59 98.03 97.93 97.72 98.05 98.68 97.59 98.57 98.69 Total O 2 H 3.73 3.77 3.68 3.73 3.67 3.77 3.72 3.71 3.77 3.72 3.58 3.59 3.44 3.66 3.44 3.64 3.58 3.71 3.57 3.73 3.74 3.71 3.77 3.60 3.61 3.58 3.54 3.63 3.75 3.61 3.75 3.67 3.34 3.51 3.69 3.76 3.70 3.69 3.68 3.67 3.71 3.77 3.63 3.71 3.50 Cl 0.06 0.05 0.07 0.11 0.08 0.08 0.05 0.07 0.09 0.09 0.10 0.21 0.19 0.09 0.10 0.19 0.20 0.13 0.10 0.09 0.09 0.10 0.11 0.17 0.20 0.20 0.22 0.21 0.09 0.09 0.09 0.09 0.19 0.23 0.09 0.09 0.10 0.11 0.11 0.12 0.08 0.10 0.09 0.09 0.21 F 0.53 0.48 0.51 0.48 0.38 0.34 0.48 0.49 0.34 0.44 0.71 0.48 0.91 0.49 0.96 0.50 0.57 0.39 0.69 0.40 0.45 0.41 0.38 0.54 0.45 0.57 0.60 0.53 0.35 0.65 0.43 0.56 1.18 0.66 0.48 0.40 0.51 0.49 0.46 0.45 0.46 0.38 0.54 0.49 0.81 O 2 K 7.71 7.93 7.72 8.37 7.77 7.99 8.71 8.65 8.82 8.68 8.70 8.56 8.70 8.57 8.51 8.93 8.69 8.65 8.62 8.55 8.70 8.69 8.58 8.63 8.49 8.62 8.49 8.86 8.53 8.51 8.60 8.73 8.72 8.59 8.54 8.71 8.62 8.64 8.49 8.64 8.44 8.73 8.61 8.59 8.80 O 2 0.64 0.76 0.39 0.52 0.48 0.38 0.59 0.61 0.54 0.51 0.54 0.54 0.53 0.54 0.51 0.56 0.53 0.54 0.50 0.60 0.62 0.60 0.57 0.55 0.54 0.56 0.54 0.52 0.61 0.58 0.54 0.53 0.44 0.50 0.56 0.57 0.53 0.58 0.48 0.51 0.56 0.58 0.50 0.50 0.37 Na MgO 11.07 11.08 11.78 11.36 11.58 11.20 11.44 11.38 11.50 13.11 13.16 10.99 10.66 10.00 13.99 13.97 13.83 14.08 13.70 12.01 13.84 13.60 13.49 13.63 14.08 14.04 13.84 13.97 12.08 14.09 14.11 14.28 14.08 12.00 13.82 14.10 14.22 14.23 13.73 13.81 14.18 14.47 13.78 13.86 12.12 0.17 0.19 0.26 0.27 0.31 0.29 0.31 0.36 0.37 0.37 0.40 0.46 0.45 0.35 0.40 0.43 0.44 0.37 0.40 0.33 0.36 0.32 0.33 0.43 0.44 0.45 0.45 0.48 0.31 0.34 0.33 0.32 0.40 0.44 0.33 0.32 0.32 0.27 0.37 0.37 0.29 0.30 0.37 0.40 0.40 MnO FeO 12.37 12.84 13.46 15.07 14.92 14.74 13.43 13.69 13.74 13.56 13.93 16.97 16.34 13.48 13.88 16.99 16.96 14.03 13.80 13.24 13.48 13.20 13.35 16.89 16.78 17.18 16.65 16.37 13.36 13.17 13.24 13.15 16.26 16.74 13.63 13.39 13.40 12.98 13.90 13.80 13.44 13.15 13.62 13.60 14.90 3 O 2 2.43 2.52 2.64 2.96 2.93 2.89 2.63 2.68 2.69 2.66 2.73 3.33 3.20 2.64 2.72 3.33 3.33 2.75 2.71 2.60 2.64 2.59 2.62 3.31 3.29 3.37 3.27 3.21 2.62 2.58 2.60 2.58 3.19 3.28 2.67 2.63 2.63 2.55 2.73 2.71 2.64 2.58 2.67 2.67 2.92 Fe 2 6.23 6.11 5.35 5.62 5.32 5.49 4.71 4.57 4.60 4.56 4.36 4.47 4.12 4.48 4.55 4.19 4.50 4.62 4.59 4.51 4.61 4.43 4.63 4.35 4.45 4.42 4.47 4.28 4.50 4.24 4.58 4.45 4.30 4.25 4.68 4.49 4.32 4.49 4.41 4.45 4.30 4.34 4.37 4.46 4.06 TiO 3 O 2 Al 14.50 14.81 13.96 14.04 13.93 13.44 14.10 13.56 13.51 13.28 13.34 13.78 12.72 13.36 13.31 12.87 13.09 13.62 13.58 13.74 14.24 13.77 14.23 13.27 13.39 13.23 13.01 12.66 13.54 13.41 13.42 13.47 13.06 12.77 13.78 13.77 13.80 13.44 13.28 12.96 13.59 13.77 13.10 13.56 12.22 2 SiO 36.62 36.29 37.91 37.20 36.09 38.34 35.97 36.44 36.26 36.50 36.46 35.10 36.83 36.12 36.07 36.41 35.92 35.88 35.81 36.19 36.06 36.15 36.29 35.77 35.43 35.72 35.93 36.79 36.15 36.55 36.87 36.74 36.84 36.16 35.95 36.57 36.44 36.56 36.29 36.23 36.36 36.51 36.31 36.64 38.38 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 06TA1 06TA2 06TB1 06TD1 06TD2 06TE1 168TA1 168TB1 168TB2 168TC1 168TC2 168TD1 168TD2 168TE1 168TE2 168TL1 168TL2 168TM1 168TM2 168TN1 168TN2 168TQ1 168TQ2 168TR1 168TR2 168TT2 168TU1 168TU2 168TV1 168TV2 169TA1 169TA2 169TAC1 169TAC2 169TC1 169TC2 169TG1 169TG2 169TJ1 169TJ2 169TK1 169TL1 169TP1 169TP2 169TT1 sample no. Appendix 3. 70 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 98.55 99.26 98.97 99.18 99.27 97.35 97.20 97.66 97.70 97.60 97.07 99.00 99.24 98.77 98.49 97.28 96.63 97.07 97.58 98.85 98.20 98.10 98.55 97.66 98.24 99.08 99.96 98.35 98.12 97.31 97.16 98.39 98.40 98.34 98.81 99.45 99.65 99.64 99.59 98.69 97.32 99.22 TOTAL 100.26 100.04 100.71 0.39 0.26 0.34 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O=F;Cl 98.94 99.52 99.31 99.18 99.27 97.35 97.20 97.66 97.70 97.60 97.07 99.00 99.24 98.77 98.49 97.28 96.63 97.07 97.58 98.85 98.20 98.10 98.55 97.66 98.24 99.08 99.96 98.35 98.12 97.31 97.16 98.39 98.40 98.34 98.81 99.45 99.65 99.64 99.59 98.69 97.32 99.22 Total 100.26 100.04 100.71 O 2 H 3.47 3.64 3.54 3.94 3.94 4.05 3.94 3.93 3.95 3.95 3.93 3.91 3.94 3.96 3.94 3.93 3.95 3.92 3.84 3.87 3.93 3.90 3.90 3.91 3.96 3.98 3.96 3.98 4.00 3.99 3.98 4.00 3.92 3.92 3.98 3.98 3.98 4.00 3.95 3.95 4.03 4.03 4.03 3.92 4.06 Cl 0.18 0.18 0.19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 F 0.83 0.53 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 K 8.67 8.78 8.68 8.85 8.98 8.81 8.55 8.62 8.60 8.71 8.65 8.54 8.87 8.90 8.83 8.71 8.38 8.27 8.37 8.41 8.73 8.58 8.43 8.60 8.51 8.69 8.73 8.93 8.71 8.69 8.56 8.61 8.60 8.14 8.29 8.17 8.87 8.91 9.01 8.89 9.13 9.09 8.73 8.20 8.77 O 2 0.47 0.49 0.49 0.20 0.16 0.30 0.27 0.27 0.28 0.33 0.16 0.18 0.11 0.16 0.18 0.24 0.13 0.14 0.20 0.17 0.16 0.20 0.22 0.12 0.19 0.17 0.08 0.09 0.32 0.36 0.28 0.26 0.34 0.22 0.26 0.34 0.34 0.25 0.24 0.18 0.25 0.31 0.39 0.25 0.43 Na MgO 11.80 11.96 11.08 11.28 11.34 11.49 11.36 11.50 11.92 11.78 12.34 12.29 12.01 14.08 14.09 14.00 14.28 14.21 13.48 13.49 12.09 12.31 12.56 12.48 13.84 13.67 14.09 14.13 12.16 12.13 14.79 14.55 12.00 12.29 13.68 13.61 14.06 14.03 14.32 14.02 14.91 14.78 15.51 13.53 15.53 0.45 0.44 0.46 0.39 0.38 0.26 0.26 0.22 0.24 0.26 0.30 0.26 0.34 0.33 0.19 0.22 0.28 0.20 0.32 0.37 0.37 0.33 0.37 0.30 0.26 0.20 0.33 0.37 0.16 0.20 0.29 0.44 0.16 0.18 0.22 0.23 0.29 0.25 0.33 0.43 0.25 0.27 0.17 0.18 0.11 MnO FeO 11.72 11.80 16.07 16.27 16.44 16.48 16.45 13.87 13.08 13.07 13.09 13.09 13.88 13.81 16.42 15.85 15.99 15.96 13.01 13.17 17.02 16.62 16.65 16.59 16.69 16.84 13.21 13.28 16.06 16.50 12.53 12.55 16.97 17.14 13.70 14.02 13.90 13.98 13.12 13.27 16.55 16.93 13.16 13.16 14.37 3 O 2 3.15 3.19 3.23 3.23 3.23 2.72 2.57 2.56 2.57 2.57 2.72 2.71 3.22 3.11 3.14 3.13 2.55 2.58 3.34 3.26 3.27 3.25 3.27 3.30 2.59 2.60 3.15 3.24 2.46 2.46 3.33 3.36 2.69 2.75 2.73 2.74 2.57 2.60 3.25 3.32 2.58 2.58 2.30 2.82 2.32 Fe 2 4.20 3.97 4.13 4.36 4.31 4.43 4.16 4.35 4.32 4.35 4.53 4.36 4.27 4.29 3.72 3.64 4.35 4.42 4.25 4.68 4.21 4.16 4.24 4.65 4.36 4.35 4.13 4.19 4.45 4.27 4.24 4.29 4.34 4.24 4.41 4.51 4.42 4.31 4.15 4.24 4.37 4.24 4.45 4.29 4.31 TiO 3 O 2 Al 12.05 12.40 12.63 13.16 13.21 14.47 13.93 13.79 13.65 13.59 13.89 13.88 12.76 13.06 13.48 13.45 13.75 13.50 13.67 13.49 13.42 13.27 13.33 13.39 13.98 13.95 12.67 13.15 13.66 13.60 12.99 12.85 13.99 14.17 14.03 13.82 13.24 13.78 12.40 12.99 13.03 13.00 13.60 13.75 13.64 2 SiO 37.06 37.34 36.81 36.77 36.65 37.27 36.50 36.39 36.68 36.64 36.06 35.93 36.98 37.27 36.74 36.73 37.04 36.76 34.98 35.43 36.77 36.43 36.29 35.94 36.51 36.89 37.81 37.38 37.27 37.45 37.40 37.47 35.89 35.91 36.51 36.60 37.19 37.42 37.65 36.94 37.93 38.13 37.79 36.01 38.25 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 169TT2 169TX1 169TX2 197TAB1 197TAB2 197TAF1 197TC1 197TC2 197TD1 197TD2 197TE1 197TE2 197TF1 197TF2 197TJ1 197TJ2 197TL1 197TL2 197TM1 197TM2 197TN1 197TN2 197TQ1 197TQ2 197TY1 197TY2 197TZ1 197TZ2 199TA1 199TA2 199TAE1 199TAE2 199TAH1 199TAH2 199TAL1 199TAL2 199TB1 199TB2 199TC1 199TC2 199TE1 199TE2 199TF1 199TF1 199TF2 sample no. Appendix 3. Appendix 3 71 98.21 99.25 99.79 97.61 97.98 99.06 98.13 98.19 98.58 98.66 98.27 98.02 97.89 98.61 97.84 98.09 97.71 98.61 98.59 97.79 98.44 97.47 96.64 97.24 97.60 96.84 98.75 98.91 99.23 98.39 99.96 99.53 99.96 99.58 TOTAL 100.41 100.52 100.66 100.05 100.50 100.16 100.67 101.08 100.65 100.05 100.49 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.29 0.26 0.38 0.59 0.29 0.42 0.44 0.41 0.31 0.44 0.32 0.34 0.41 0.28 O=F;Cl 98.21 99.25 99.79 97.61 97.98 99.06 98.13 98.19 98.58 98.66 98.27 98.02 97.89 98.61 97.84 98.09 97.71 98.61 98.59 97.79 98.44 97.47 96.64 97.24 97.60 96.84 98.75 98.91 99.23 98.39 99.83 Total 100.41 100.81 100.22 101.04 100.64 100.93 100.40 100.57 100.98 100.02 101.40 100.99 100.46 100.77 O 2 H 3.95 3.96 3.97 3.96 3.98 3.92 3.98 3.99 3.99 3.97 3.99 3.96 3.97 3.95 3.99 3.96 3.98 3.95 3.98 3.99 3.94 3.98 3.96 3.92 3.95 3.95 3.93 3.99 4.00 4.00 3.97 3.74 3.74 3.58 3.37 3.68 3.57 3.53 3.57 3.72 3.51 3.72 3.67 3.55 3.72 Cl 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.07 0.20 0.09 0.11 0.11 0.11 0.10 0.12 0.09 0.09 0.09 0.09 0.08 F 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.64 0.57 0.80 1.35 0.64 0.95 0.99 0.91 0.67 0.99 0.71 0.76 0.92 0.62 O 2 K 8.27 8.40 8.53 8.11 8.28 8.47 8.52 8.33 8.02 8.54 8.54 8.58 8.51 8.47 8.22 8.35 7.72 8.31 8.48 8.26 8.33 8.39 8.42 8.46 8.35 8.21 8.21 8.36 8.16 8.50 8.52 8.66 8.82 8.69 8.83 8.66 8.83 8.96 8.84 9.03 8.96 8.94 8.88 8.85 8.93 O 2 0.24 0.15 0.17 0.37 0.34 0.23 0.18 0.35 0.44 0.36 0.33 0.43 0.37 0.36 0.31 0.35 0.23 0.24 0.32 0.36 0.27 0.31 0.41 0.38 0.47 0.38 0.30 0.29 0.38 0.28 0.26 0.54 0.58 0.49 0.57 0.55 0.56 0.50 0.58 0.54 0.57 0.57 0.55 0.54 0.51 Na MgO 11.52 11.96 11.38 13.70 12.33 12.60 14.14 14.24 14.98 14.68 13.96 14.02 13.75 13.68 13.84 13.68 14.00 13.12 13.68 14.03 14.21 13.56 14.32 14.40 14.30 14.48 13.89 14.23 14.13 14.01 13.76 13.74 13.92 13.66 13.59 13.50 13.85 13.93 13.60 14.37 13.78 14.21 14.24 13.11 13.45 0.30 0.38 0.35 0.15 0.10 0.34 0.36 0.18 0.21 0.27 0.25 0.24 0.21 0.22 0.27 0.15 0.15 0.20 0.24 0.25 0.27 0.26 0.18 0.16 0.17 0.22 0.16 0.25 0.24 0.28 0.27 0.36 0.31 0.34 0.23 0.35 0.33 0.29 0.34 0.32 0.29 0.30 0.34 0.36 0.43 MnO FeO 14.42 16.49 16.78 13.28 13.17 17.39 17.53 12.82 13.02 13.97 13.62 14.02 13.24 13.81 13.83 13.56 14.56 13.87 13.80 13.61 13.81 13.75 12.72 12.53 12.70 13.46 12.93 13.77 14.07 14.31 13.99 13.69 13.73 16.46 13.49 13.65 13.83 13.46 13.87 13.26 13.60 13.64 13.53 14.45 14.27 3 O 2 2.83 3.23 3.29 2.61 2.58 3.41 3.44 2.51 2.55 2.74 2.67 2.75 2.60 2.71 2.71 2.66 2.86 2.72 2.71 2.67 2.71 2.70 2.49 2.46 2.49 2.64 2.54 2.70 2.76 2.81 2.74 2.68 2.69 3.23 2.64 2.68 2.71 2.64 2.72 2.60 2.67 2.68 2.65 2.83 2.80 Fe 2 4.42 4.12 4.21 4.35 4.36 4.37 4.32 4.42 4.39 4.43 4.07 4.36 4.58 4.38 4.40 4.38 3.88 4.12 4.38 4.28 4.76 4.10 4.39 4.44 4.10 4.52 4.37 4.48 4.28 4.59 4.03 4.64 4.69 4.18 4.70 4.77 4.47 4.44 4.76 4.56 4.61 4.68 4.72 4.75 4.68 TiO 3 O 2 Al 13.85 13.15 12.83 14.16 13.98 13.19 13.15 13.69 13.96 13.80 13.96 13.89 14.12 13.80 14.30 13.90 14.20 14.00 13.97 13.96 14.41 13.78 14.19 14.41 14.34 14.39 13.94 14.04 14.11 13.84 13.88 14.35 14.94 13.88 15.34 15.19 14.53 14.44 14.63 14.29 14.72 14.49 14.56 14.77 14.49 2 SiO 36.23 37.04 37.06 36.48 36.95 36.22 36.97 36.86 36.93 36.54 37.21 36.29 36.74 36.35 36.90 36.53 37.39 36.62 36.70 37.00 35.73 36.85 36.31 35.58 36.19 35.94 36.23 36.74 36.90 36.86 36.99 37.51 36.42 37.81 36.44 36.05 37.19 37.11 36.65 37.50 36.23 37.37 37.00 36.24 36.79 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 199TF2 199TH1 199TH2 199TQ1 199TQ2 199TR1 199TR2 199TV1 199TV2 203TA1 203TA2 203TB1 203TB2 203TB3 203TC1 203TC2 203TE1 203TE3 203TE4 203TF1 203TF2 203TF3 203TH1 203TH2 203TH3 203TJ1 203TJ2 203TP1 203TP2 203TQ1 203TQ2 204TA1 204TA2 204TAB2 204TAC1 204TAC2 204TB1 204TB2 204TC1 204TC2 204TD1 204TF1 204TF2 204TG1 204TG2 sample no. Appendix 3. 72 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 99.85 98.90 98.54 99.66 99.25 98.89 97.28 96.97 97.72 99.42 95.78 99.71 99.37 98.95 99.40 98.50 98.87 98.12 98.87 98.78 99.57 99.20 98.62 99.22 98.56 99.26 99.94 99.32 98.50 99.98 TOTAL 100.07 100.65 100.06 100.80 100.06 100.15 100.36 100.76 100.84 100.41 100.44 100.11 101.20 100.02 100.02 0.37 0.46 0.28 0.26 0.32 0.39 0.48 0.41 0.29 0.39 0.28 0.41 0.39 0.30 0.38 2.02 1.95 2.34 1.61 2.00 1.50 1.88 2.24 1.98 1.61 1.79 1.84 1.92 1.23 1.76 1.66 1.74 1.52 1.70 1.13 1.44 1.58 1.63 1.61 1.67 1.75 1.87 1.57 1.54 1.69 O=F;Cl 99.31 99.29 98.47 99.60 97.76 99.73 99.78 99.91 Total 100.44 101.11 100.35 101.06 100.17 100.44 100.63 100.65 101.15 101.12 100.82 100.83 100.41 101.58 100.56 101.61 101.59 100.49 101.66 101.32 101.16 100.80 101.32 100.63 100.62 101.54 101.71 101.01 100.79 100.25 100.83 100.23 101.02 101.81 100.89 100.04 101.67 O 2 H 3.64 3.53 3.73 3.76 3.66 3.60 3.49 3.51 3.71 3.62 3.75 3.59 3.61 3.70 3.65 1.76 1.84 1.43 2.16 1.68 2.20 1.80 1.55 1.68 2.20 2.03 1.96 1.91 2.57 2.05 2.16 2.11 2.30 2.14 2.70 2.39 2.25 2.19 2.24 2.15 2.08 1.97 2.29 2.28 2.18 Cl 0.09 0.09 0.11 0.11 0.11 0.09 0.12 0.13 0.11 0.09 0.09 0.11 0.10 0.10 0.09 0.12 0.10 0.07 0.10 0.13 0.10 0.11 0.12 0.13 0.11 0.10 0.12 0.10 0.15 0.11 0.15 0.17 0.12 0.10 0.11 0.09 0.10 0.12 0.09 0.10 0.08 0.09 0.11 0.10 0.12 F 0.83 1.05 0.61 0.56 0.70 0.87 1.07 0.90 0.62 0.87 0.62 0.92 0.88 0.67 0.86 4.73 4.57 5.51 3.76 4.69 3.52 4.40 5.25 4.64 3.77 4.19 4.31 4.51 2.85 4.12 3.86 4.05 3.55 3.98 2.62 3.38 3.71 3.80 3.78 3.92 4.12 4.40 3.67 3.60 3.94 O 2 K 8.60 8.91 8.54 8.84 8.81 8.97 8.90 8.84 8.77 8.88 8.95 8.80 8.84 8.89 8.87 8.38 8.62 8.79 8.29 8.31 7.94 7.79 8.69 8.03 8.72 8.64 8.55 8.53 8.17 8.44 8.49 8.59 8.66 8.65 8.29 8.70 8.58 8.69 8.75 8.65 8.72 8.75 8.78 8.45 8.78 O 2 0.55 0.55 0.60 0.60 0.51 0.55 0.52 0.52 0.53 0.57 0.54 0.56 0.54 0.55 0.59 0.64 0.58 0.61 0.49 0.60 0.47 0.48 0.58 0.58 0.60 0.62 0.55 0.64 0.55 0.54 0.60 0.63 0.60 0.61 0.49 0.61 0.63 0.61 0.59 0.57 0.60 0.55 0.53 0.62 0.62 Na MgO 13.70 13.96 13.80 13.81 13.68 13.92 13.80 13.20 13.30 13.95 13.99 13.87 13.83 14.23 14.25 16.46 14.90 16.94 13.36 14.43 13.19 13.73 16.77 15.29 14.73 15.97 15.90 16.25 13.39 15.65 16.41 17.00 13.69 14.51 12.72 13.91 14.99 15.80 15.85 15.66 15.68 15.92 15.53 15.06 15.40 0.26 0.33 0.33 0.35 0.36 0.35 0.26 0.37 0.41 0.29 0.32 0.29 0.31 0.30 0.34 0.18 0.34 0.34 0.32 0.32 0.36 0.46 0.23 0.21 0.37 0.29 0.31 0.22 0.45 0.34 0.24 0.29 0.42 0.37 0.45 0.41 0.24 0.21 0.31 0.31 0.36 0.32 0.17 0.21 0.28 MnO 9.96 9.68 9.21 FeO 11.39 11.12 11.28 11.78 11.12 11.02 11.32 11.27 13.38 13.78 13.63 13.90 13.63 13.21 13.81 14.07 14.37 13.87 13.67 13.57 13.61 13.13 13.62 10.04 12.61 14.21 12.03 13.87 14.26 10.25 10.55 12.94 10.38 13.79 13.83 12.41 14.25 13.23 10.94 10.59 10.44 10.82 3 O 2 2.62 2.70 2.67 2.73 2.67 2.59 2.71 2.76 2.82 2.72 2.68 2.66 2.67 2.57 2.67 1.97 2.47 1.95 2.79 2.36 2.72 2.80 2.01 2.07 2.54 2.23 2.18 2.04 2.70 2.21 1.90 1.81 2.71 2.43 2.80 2.60 2.31 2.15 2.08 2.05 2.18 2.16 2.12 2.22 2.21 Fe 2 4.50 4.86 4.46 5.01 4.77 4.56 4.73 4.58 4.70 4.55 4.69 4.49 4.46 4.72 4.56 5.09 4.35 4.38 4.25 4.50 4.34 4.22 4.45 4.37 4.43 4.55 4.51 4.38 4.69 4.57 4.87 4.69 4.55 4.52 4.71 4.47 4.65 4.53 4.57 4.60 4.17 4.31 4.86 4.95 4.67 TiO 3 O 2 Al 14.63 14.53 14.71 15.05 14.83 14.64 14.96 14.22 14.53 14.78 14.82 14.48 14.46 14.50 14.60 13.89 13.47 13.68 13.69 13.98 13.80 13.65 13.71 13.42 13.57 13.49 13.87 13.53 14.13 13.89 14.05 13.94 13.50 13.49 13.98 13.42 13.78 13.51 13.61 13.49 13.34 13.32 13.51 13.74 13.72 2 SiO 37.64 36.82 37.16 36.34 36.44 37.09 36.26 36.21 36.78 36.96 37.00 37.48 37.52 37.05 37.48 37.30 37.76 37.93 37.07 36.26 35.96 35.90 38.05 36.79 37.34 37.66 37.42 38.83 36.29 37.43 37.37 38.13 37.61 38.50 36.79 37.80 37.77 37.70 38.37 38.29 38.57 39.00 38.50 37.49 38.48 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 204TJ1 204TJ2 204TM1 204TM2 204TN1 204TN2 204TP1 204TQ1 204TQ2 204TS1 204TS2 204TU1 204TU2 204TX1 204TX2 21TA2 21TB1 21TB2 21TC1 21TC2 21TD1 21TD2 21TE1 21TE2 21TF1 21TF2 21TG1 21TG2 21TH1 21TH2 21TM1 21TM2 24TA1 24TA2 24TC1 24TC2 24TD1 24TD2 24TE1 24TE2 24TF1 24TF2 24TG1 24TG2 24TH1 sample no. Appendix 3. Appendix 3 73 99.79 99.48 98.14 99.05 98.79 98.75 99.02 98.60 99.20 96.73 98.80 99.95 98.88 99.77 99.51 99.12 98.62 99.29 99.34 98.84 98.79 97.93 98.65 98.80 98.55 98.27 99.68 98.67 97.60 98.52 97.95 98.07 99.44 99.12 99.96 99.19 99.33 99.02 99.69 99.68 TOTAL 100.90 100.08 100.02 100.40 100.36 1.54 0.91 1.51 0.66 1.43 1.33 1.38 1.33 1.83 1.37 1.42 1.39 1.52 1.51 1.57 1.42 1.52 0.95 1.19 0.46 0.58 0.52 0.84 0.37 0.85 0.35 0.64 1.05 1.19 1.03 0.60 0.95 0.44 0.74 0.23 0.20 0.21 0.18 0.42 0.37 0.24 0.17 0.19 0.22 0.25 O=F;Cl 98.80 99.97 98.12 99.80 99.75 99.92 99.35 99.63 98.30 99.50 99.15 99.18 99.33 99.71 98.20 99.47 98.39 98.81 99.64 99.30 99.56 99.57 99.19 99.89 99.90 Total 101.33 100.39 102.41 100.48 100.12 101.46 100.07 100.85 100.62 100.32 101.46 100.45 101.19 101.02 100.07 100.87 100.25 100.61 100.38 100.60 O 2 H 2.32 2.95 2.36 3.19 2.39 2.49 2.48 2.46 1.97 2.46 2.44 2.34 2.28 2.37 2.25 2.44 2.33 2.94 2.64 3.48 3.36 3.40 3.01 3.56 3.04 3.58 3.25 2.76 2.70 2.83 3.26 2.91 3.44 3.11 3.79 3.80 3.82 3.81 3.52 3.56 3.75 3.82 3.81 3.78 3.78 Cl 0.11 0.12 0.10 0.11 0.10 0.13 0.09 0.12 0.09 0.12 0.10 0.14 0.10 0.12 0.12 0.14 0.12 0.09 0.10 0.09 0.09 0.10 0.10 0.07 0.05 0.08 0.09 0.19 0.20 0.15 0.06 0.08 0.10 0.09 0.07 0.07 0.07 0.05 0.11 0.11 0.08 0.06 0.08 0.09 0.06 F 3.61 2.10 3.53 1.51 3.35 3.09 3.23 3.09 4.29 3.19 3.33 3.22 3.55 3.52 3.67 3.30 3.54 2.21 2.77 1.04 1.33 1.17 1.94 0.84 2.00 0.79 1.46 2.40 2.71 2.37 1.39 2.21 1.00 1.71 0.51 0.43 0.46 0.39 0.94 0.81 0.52 0.36 0.42 0.48 0.55 O 2 K 8.82 8.50 8.94 8.27 8.41 8.41 8.59 8.17 8.69 8.50 8.60 8.03 8.58 8.72 8.31 8.49 8.49 8.66 8.84 8.87 8.69 8.66 8.70 8.46 8.53 8.77 8.76 9.04 9.40 9.73 8.83 8.67 8.93 8.96 8.76 8.72 8.84 8.72 8.62 8.47 8.62 8.39 8.74 8.60 8.93 O 2 0.63 0.50 0.60 0.49 0.47 0.51 0.61 0.56 0.58 0.55 0.60 0.50 0.58 0.56 0.58 0.63 0.60 0.60 0.54 0.42 0.40 0.48 0.62 0.68 0.66 0.44 0.52 0.37 0.40 0.20 0.42 0.45 0.48 0.45 0.57 0.55 0.59 0.55 0.57 0.54 0.65 0.60 0.57 0.55 0.57 Na MgO 15.10 12.50 13.97 12.13 13.94 13.46 13.94 12.37 14.46 14.48 15.20 12.74 13.36 14.75 14.16 14.12 14.44 13.84 14.07 13.08 13.41 13.88 13.48 14.82 14.31 13.59 13.70 13.58 14.88 15.12 13.43 13.85 13.72 13.64 14.33 14.22 14.50 14.08 12.72 12.81 14.24 13.96 14.24 14.10 14.67 0.24 0.45 0.38 0.45 0.42 0.44 0.42 0.47 0.30 0.33 0.33 0.46 0.45 0.22 0.28 0.25 0.29 0.23 0.22 0.30 0.30 0.27 0.26 0.24 0.21 0.31 0.29 0.18 0.16 0.16 0.26 0.20 0.28 0.29 0.24 0.23 0.26 0.26 0.39 0.39 0.22 0.21 0.25 0.28 0.21 MnO FeO 11.48 11.85 11.28 11.82 11.95 11.77 14.88 13.55 14.63 12.91 12.93 13.41 14.41 12.15 13.42 13.23 12.32 12.50 12.09 12.84 12.64 13.87 13.50 13.52 14.10 12.01 12.32 13.60 13.38 13.45 13.12 13.25 13.16 13.15 12.99 13.04 13.13 12.98 14.74 14.43 12.89 13.27 13.08 13.27 12.93 3 O 2 2.25 2.92 2.66 2.87 2.53 2.54 2.63 2.83 2.32 2.38 2.21 2.63 2.59 2.32 2.42 2.45 2.37 2.52 2.48 2.72 2.65 2.65 2.76 2.36 2.42 2.67 2.62 2.64 2.34 2.31 2.57 2.60 2.58 2.58 2.55 2.56 2.57 2.55 2.89 2.83 2.53 2.60 2.57 2.60 2.54 Fe 2 4.83 4.66 4.67 4.76 4.69 4.91 4.55 4.91 4.62 4.59 4.70 4.62 4.38 4.68 4.55 5.18 5.03 4.52 4.37 4.65 4.47 4.48 4.41 4.68 4.53 4.56 4.55 4.66 4.60 4.48 4.42 4.31 4.57 4.51 5.00 5.02 4.94 4.89 5.74 5.69 5.10 4.90 5.00 4.97 4.90 TiO 3 O 2 Al 13.63 14.06 13.51 14.26 13.75 14.27 13.60 14.41 13.70 13.59 13.72 13.37 13.30 13.64 13.22 14.16 14.13 14.69 14.55 13.97 14.05 14.17 13.99 14.43 14.84 14.53 14.22 14.00 14.42 13.52 14.03 14.28 13.92 13.95 14.60 14.64 14.37 14.61 14.27 14.20 14.63 14.76 14.52 14.46 14.39 2 SiO 38.31 36.75 38.14 36.13 37.52 36.94 37.91 36.27 37.98 37.63 38.11 36.65 37.92 38.74 38.57 37.53 37.59 36.93 36.58 37.26 37.67 36.57 36.26 36.15 36.59 36.23 36.34 36.06 37.11 37.07 36.41 36.66 36.21 36.37 36.84 36.36 37.06 36.41 35.87 35.72 36.34 36.26 36.61 36.72 37.07 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 24TH2 24TK1 24TK2 24TL1 24TL2 24TM1 24TM2 24TN1 24TN2 24TR1 24TR2 24TU1 24TU2 24TV1 24TV2 24TW1 24TW2 44TA1 44TA2 44TB1 44TB2 44TC1 44TC2 44TD1 44TD2 44TE1 44TE2 44TF1 44TF2 44TH2 44TR1 44TR2 44TS1 44TS2 89T4A1 89T4A2 89T4B1 89T4B2 89T4D1 89T4D2 89T4E1 89T4E2 89T4F1 89T4F2 89T4G1 sample no. Appendix 3. 74 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 99.47 99.33 99.72 99.11 99.53 98.39 99.98 99.27 98.55 99.94 99.44 99.12 99.96 99.19 99.33 99.02 99.69 99.68 99.47 99.33 99.72 99.11 99.53 98.39 99.98 99.27 98.55 99.94 99.50 98.77 99.97 99.20 TOTAL 100.26 100.02 100.40 100.36 100.26 101.00 100.96 100.24 100.81 100.70 100.47 100.53 100.30 0.22 0.34 0.20 0.18 0.19 0.19 0.22 0.31 0.31 0.18 0.22 0.23 0.20 0.21 0.18 0.42 0.37 0.24 0.17 0.19 0.22 0.25 0.22 0.34 0.20 0.18 0.19 0.19 0.22 0.31 0.31 0.18 0.22 0.47 0.19 0.26 0.34 0.54 0.49 0.55 0.51 0.37 0.33 0.34 0.32 O=F;Cl 99.70 99.67 99.92 99.29 99.73 98.58 99.58 98.86 99.64 99.30 99.56 99.57 99.19 99.89 99.90 99.70 99.67 99.92 99.29 99.73 98.58 99.58 98.86 99.32 99.52 Total 100.20 100.13 100.48 100.25 100.61 100.38 100.60 100.20 100.13 100.48 101.47 101.15 100.50 101.15 101.24 100.00 100.98 100.89 100.31 100.64 O 2 H 3.77 3.64 3.83 3.82 3.82 3.77 3.80 3.65 3.62 3.84 3.82 3.79 3.80 3.82 3.81 3.52 3.56 3.75 3.82 3.81 3.78 3.78 3.77 3.64 3.83 3.82 3.82 3.77 3.80 3.65 3.62 3.84 3.82 3.45 3.82 3.63 3.65 3.43 3.45 3.35 3.46 3.62 3.65 3.64 3.57 Cl 0.06 0.07 0.05 0.06 0.06 0.08 0.08 0.08 0.08 0.05 0.08 0.07 0.07 0.07 0.05 0.11 0.11 0.08 0.06 0.08 0.09 0.06 0.06 0.07 0.05 0.06 0.06 0.08 0.08 0.08 0.08 0.05 0.08 0.08 0.08 0.10 0.12 0.12 0.12 0.12 0.10 0.10 0.10 0.10 0.19 F 0.50 0.77 0.44 0.39 0.43 0.41 0.48 0.69 0.69 0.41 0.47 0.51 0.43 0.46 0.39 0.94 0.81 0.52 0.36 0.42 0.48 0.55 0.50 0.77 0.44 0.39 0.43 0.41 0.48 0.69 0.69 0.41 0.47 1.07 0.40 0.56 0.74 1.22 1.11 1.24 1.15 0.82 0.74 0.76 0.66 O 2 K 8.60 8.46 8.69 8.37 8.54 8.52 8.70 8.37 8.58 8.73 8.65 8.76 8.72 8.84 8.72 8.62 8.47 8.62 8.39 8.74 8.60 8.93 8.60 8.46 8.69 8.37 8.54 8.52 8.70 8.37 8.58 8.73 8.65 8.88 8.87 8.37 9.15 9.01 8.28 8.02 8.94 8.77 8.56 8.68 8.81 O 2 0.60 0.59 0.67 0.63 0.68 0.57 0.61 0.61 0.57 0.58 0.59 0.57 0.55 0.59 0.55 0.57 0.54 0.65 0.60 0.57 0.55 0.57 0.60 0.59 0.67 0.63 0.68 0.57 0.61 0.61 0.57 0.58 0.59 0.63 0.67 0.69 0.50 0.48 0.42 0.42 0.47 0.47 0.49 0.47 0.50 Na 9.09 MgO 11.51 11.75 14.26 14.45 14.74 14.17 14.53 14.18 14.71 13.79 13.65 14.67 14.75 14.33 14.22 14.50 14.08 12.72 12.81 14.24 13.96 14.24 14.10 14.67 14.26 14.45 14.74 14.17 14.53 14.18 14.71 13.79 13.65 14.67 14.75 12.37 13.70 13.40 13.04 12.74 13.67 13.65 13.63 13.51 0.24 0.19 0.23 0.21 0.18 0.21 0.23 0.24 0.26 0.25 0.24 0.24 0.23 0.26 0.26 0.39 0.39 0.22 0.21 0.25 0.28 0.21 0.24 0.19 0.23 0.21 0.18 0.21 0.23 0.24 0.26 0.25 0.24 0.31 0.34 0.25 0.65 0.64 0.38 0.39 0.63 0.58 0.63 0.66 0.41 MnO FeO 13.09 12.71 12.34 12.79 12.65 12.68 12.77 13.72 13.44 12.93 12.77 12.99 13.04 13.13 12.98 14.74 14.43 12.89 13.27 13.08 13.27 12.93 13.09 12.71 12.34 12.79 12.65 12.68 12.77 13.72 13.44 12.93 12.77 17.08 15.57 19.40 14.72 14.45 14.53 14.77 14.36 14.40 14.35 14.53 16.34 3 O 2 2.57 2.49 2.42 2.51 2.48 2.49 2.50 2.69 2.64 2.54 2.51 2.55 2.56 2.57 2.55 2.89 2.83 2.53 2.60 2.57 2.60 2.54 2.57 2.49 2.42 2.51 2.48 2.49 2.50 2.69 2.64 2.54 2.51 3.35 3.05 3.80 2.89 2.83 2.85 2.90 2.82 2.82 2.81 2.85 3.21 Fe 2 5.00 5.31 5.12 5.34 5.15 5.04 4.89 5.15 5.01 4.98 5.19 5.00 5.02 4.94 4.89 5.74 5.69 5.10 4.90 5.00 4.97 4.90 5.00 5.31 5.12 5.34 5.15 5.04 4.89 5.15 5.01 4.98 5.19 5.57 5.22 5.15 3.97 3.99 4.85 4.77 4.12 4.21 3.93 4.09 4.26 TiO 3 O 2 Al 14.64 14.60 14.45 14.89 14.90 14.60 14.45 14.68 14.35 14.41 14.37 14.60 14.64 14.37 14.61 14.27 14.20 14.63 14.76 14.52 14.46 14.39 14.64 14.60 14.45 14.89 14.90 14.60 14.45 14.68 14.35 14.41 14.37 13.70 13.51 13.20 13.45 13.64 13.92 13.92 13.45 13.70 13.44 13.51 13.17 2 SiO 36.37 36.39 36.94 36.11 36.31 36.03 36.98 35.91 35.97 36.74 37.04 36.84 36.36 37.06 36.41 35.87 35.72 36.34 36.26 36.61 36.72 37.07 36.37 36.39 36.94 36.11 36.31 36.03 36.98 35.91 35.97 36.74 37.04 35.84 37.25 36.26 37.61 38.03 37.05 36.68 37.81 37.75 37.98 37.84 36.65 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Probe 89T4G2 89T4H1 89T4H2 89T4J1 89T4J2 89T4K1 89T4K2 89T4L1 89T4L2 89T4M1 89T4M2 89TA1 89TA2 89TB1 89TB2 89TD1 89TD2 89TE1 89TE2 89TF1 89TF2 89TG1 89TG2 89TH1 89TH2 89TJ1 89TJ2 89TK1 89TK2 89TL1 89TL2 89TM1 89TM2 913TC1 913TD1 913TE1 919TB1 919TB2 919TG1 919TG2 919TM1 919TM2 919TM3 919TM4 920TA2 sample no. Appendix 3. Appendix 3 75 99.33 98.50 98.87 98.92 99.11 99.87 99.37 99.69 99.48 99.82 99.95 99.63 99.86 99.96 99.04 99.85 98.97 99.09 99.70 99.42 98.78 99.39 TOTAL 100.51 100.09 101.42 100.99 100.72 101.20 100.12 101.00 100.78 100.88 100.14 100.38 100.91 100.26 100.33 100.54 100.39 100.33 100.59 100.77 100.20 100.24 100.35 100.32 0.34 0.32 0.33 0.23 0.28 0.45 0.36 0.32 0.30 0.25 0.36 0.28 0.22 0.29 0.27 0.27 0.25 0.26 0.29 0.24 0.26 0.24 0.25 0.24 0.24 0.24 0.23 0.28 0.27 0.23 0.27 0.24 1.18 1.03 0.95 1.39 1.39 1.74 1.83 0.87 0.97 1.25 1.25 1.85 1.70 1.64 O=F;Cl 99.67 98.83 99.10 99.20 99.41 99.66 99.96 99.72 99.86 99.99 Total 100.84 100.54 101.79 101.30 100.96 101.56 100.15 100.33 101.27 101.03 101.14 100.43 100.08 100.20 100.62 101.15 100.50 100.57 100.77 100.67 100.60 100.85 101.01 101.04 100.99 101.24 101.60 100.71 100.93 101.11 101.32 100.96 100.67 100.62 102.03 101.03 O 2 H 3.59 3.64 3.58 3.73 3.63 3.45 3.61 3.65 3.59 3.69 3.60 3.67 3.76 3.61 3.63 3.76 3.77 3.76 3.69 3.74 3.73 3.75 3.76 3.78 3.75 3.76 3.77 3.72 3.73 3.78 3.73 3.76 2.65 2.83 2.96 2.57 2.44 2.04 1.93 3.00 2.91 2.68 2.59 1.97 2.19 2.23 Cl 0.18 0.19 0.10 0.09 0.18 0.20 0.22 0.21 0.22 0.21 0.20 0.14 0.12 0.22 0.21 0.13 0.15 0.13 0.13 0.14 0.13 0.13 0.13 0.05 0.08 0.12 0.14 0.14 0.13 0.15 0.13 0.14 0.13 0.14 0.19 0.20 0.19 0.19 0.18 0.16 0.16 0.22 0.21 0.27 0.19 0.20 F 0.72 0.67 0.72 0.50 0.57 0.96 0.74 0.64 0.60 0.47 0.75 0.60 0.45 0.57 0.53 0.57 0.51 0.55 0.62 0.49 0.54 0.51 0.52 0.54 0.53 0.51 0.48 0.59 0.57 0.46 0.56 0.50 2.73 2.38 2.16 3.19 3.21 4.03 4.26 1.98 2.22 2.86 2.86 4.24 3.94 3.78 O 2 K 8.19 8.63 8.64 8.25 8.03 8.75 8.94 8.83 8.24 8.90 8.82 8.97 8.90 8.40 8.48 9.11 9.05 9.18 8.97 8.74 8.95 9.00 8.87 9.18 9.13 8.93 9.03 8.87 8.92 8.78 9.09 9.06 8.34 8.17 7.69 8.27 8.36 8.61 8.65 8.36 8.24 8.34 8.79 8.56 8.77 8.44 O 2 0.46 0.48 0.51 0.48 0.44 0.57 0.52 0.52 0.47 0.48 0.53 0.53 0.51 0.47 0.53 0.49 0.52 0.43 0.48 0.43 0.50 0.49 0.52 0.50 0.48 0.47 0.49 0.51 0.49 0.54 0.53 0.50 0.46 0.53 0.45 0.39 0.56 0.60 0.58 0.37 0.43 0.44 0.40 0.53 0.46 0.45 Na 8.69 8.60 8.81 MgO 11.85 11.49 11.54 11.42 11.67 11.07 11.24 11.25 11.21 11.42 12.45 13.12 13.65 12.04 12.01 12.03 13.19 13.46 13.92 14.05 13.99 13.61 13.39 13.71 13.94 13.99 13.91 13.63 13.72 13.75 13.64 13.91 13.23 13.49 13.47 10.26 10.33 13.11 13.48 13.35 13.27 13.63 12.82 0.36 0.47 0.36 0.35 0.39 0.44 0.47 0.41 0.41 0.50 0.42 0.36 0.43 0.44 0.39 0.20 0.16 0.18 0.21 0.13 0.23 0.20 0.21 0.18 0.22 0.21 0.20 0.20 0.19 0.14 0.25 0.21 0.17 0.14 0.17 0.12 0.21 0.08 0.12 0.20 0.16 0.15 0.13 0.13 0.09 0.18 MnO FeO 11.04 11.78 16.02 16.23 14.33 14.01 16.27 16.98 16.83 16.49 16.73 17.31 17.17 14.59 14.47 16.86 17.39 14.06 14.12 14.17 14.31 14.11 13.87 13.85 13.98 14.39 14.33 14.29 14.22 14.37 14.15 13.65 14.54 14.72 16.17 15.89 14.62 10.52 15.48 12.61 12.92 17.77 16.99 12.32 14.00 10.54 3 O 2 3.14 3.18 2.81 2.75 3.19 3.33 3.30 3.23 3.28 3.40 3.37 2.86 2.84 3.31 3.41 2.76 2.77 2.78 2.81 2.77 2.72 2.72 2.74 2.82 2.81 2.80 2.79 2.82 2.78 2.68 2.85 2.89 3.17 3.12 2.87 2.06 3.04 2.47 2.53 3.48 3.33 2.42 2.75 2.07 2.16 2.31 Fe 2 3.93 4.13 4.69 4.47 4.29 4.43 4.48 4.23 4.35 4.52 4.28 4.71 4.68 4.30 4.48 4.82 4.72 4.61 4.74 5.02 4.78 4.71 4.68 4.38 4.60 4.65 4.88 4.79 4.64 4.50 4.57 4.78 5.22 5.16 4.39 4.64 4.69 5.44 5.25 4.79 4.74 4.49 5.21 5.34 6.01 4.12 TiO 3 O 2 Al 13.30 13.03 14.30 14.21 13.41 13.55 13.66 13.64 13.65 14.10 13.53 14.36 14.29 14.07 13.99 13.69 13.61 13.81 14.09 13.70 13.61 13.41 13.47 14.60 14.31 14.00 14.14 13.95 13.97 13.57 13.82 13.83 15.53 16.24 17.97 17.50 15.44 14.84 14.76 15.76 16.23 17.27 15.61 16.10 16.03 16.11 2 SiO 37.93 37.74 35.67 36.61 36.76 36.39 37.01 37.42 36.33 35.96 37.22 36.17 36.42 36.34 35.68 37.76 37.60 37.55 36.77 37.06 37.31 37.49 37.75 36.82 36.63 37.11 36.88 37.07 37.12 38.38 37.29 37.15 36.21 36.06 37.83 38.67 36.73 36.32 36.40 36.64 37.10 38.56 36.70 37.60 37.52 38.61 Recomputed Compositions (in Weight Percent) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Biotite in Samples Tertiary Recomputed Compositions (in Weight

Appendix 4 77 OH 3.733 3.760 3.737 3.743 3.793 3.816 3.757 3.748 3.814 3.766 3.633 3.710 3.511 3.740 3.509 3.709 3.671 3.778 3.640 3.785 3.762 3.776 3.791 3.693 3.727 3.671 3.649 3.690 3.808 3.664 3.772 3.709 3.383 3.617 3.746 3.786 3.730 3.736 3.749 3.751 3.758 3.793 3.715 3.742 3.556 Cl 0.015 0.013 0.018 0.028 0.021 0.021 0.013 0.018 0.023 0.023 0.026 0.055 0.049 0.023 0.026 0.049 0.052 0.034 0.026 0.023 0.023 0.026 0.028 0.044 0.053 0.052 0.058 0.054 0.023 0.023 0.023 0.023 0.049 0.060 0.023 0.023 0.026 0.028 0.028 0.031 0.021 0.026 0.023 0.023 0.054 F 0.252 0.227 0.245 0.228 0.186 0.163 0.230 0.234 0.163 0.211 0.342 0.235 0.440 0.237 0.465 0.242 0.277 0.188 0.334 0.192 0.215 0.198 0.181 0.263 0.221 0.277 0.293 0.256 0.169 0.313 0.205 0.268 0.568 0.322 0.231 0.191 0.244 0.235 0.222 0.218 0.221 0.181 0.262 0.235 0.390

Alk total 1.663 1.733 1.612 1.759 1.678 1.659 1.854 1.848 1.867 1.830 1.848 1.852 1.853 1.833 1.813 1.906 1.863 1.845 1.831 1.834 1.855 1.868 1.816 1.857 1.841 1.857 1.834 1.877 1.838 1.825 1.812 1.843 1.822 1.842 1.823 1.843 1.819 1.844 1.796 1.841 1.802 1.851 1.831 1.806 1.817 K 1.476 1.513 1.497 1.607 1.534 1.548 1.681 1.669 1.708 1.680 1.688 1.690 1.696 1.673 1.662 1.740 1.705 1.685 1.683 1.658 1.674 1.690 1.650 1.693 1.678 1.690 1.672 1.723 1.658 1.654 1.654 1.687 1.692 1.692 1.658 1.677 1.664 1.674 1.654 1.689 1.637 1.681 1.683 1.659 1.708 Na 0.186 0.220 0.115 0.152 0.144 0.112 0.173 0.179 0.159 0.150 0.159 0.162 0.157 0.160 0.151 0.166 0.158 0.160 0.148 0.177 0.181 0.177 0.167 0.164 0.162 0.167 0.162 0.154 0.180 0.171 0.158 0.156 0.130 0.150 0.165 0.167 0.155 0.171 0.142 0.152 0.165 0.170 0.149 0.147 0.109

Oct total 5.548 5.572 5.416 5.474 5.516 5.355 5.687 5.683 5.675 5.688 5.679 5.669 5.643 5.684 5.691 5.653 5.645 5.685 5.696 5.688 5.695 5.661 5.684 5.674 5.657 5.677 5.642 5.639 5.694 5.682 5.677 5.657 5.641 5.649 5.694 5.677 5.707 5.665 5.701 5.689 5.713 5.700 5.681 5.680 5.525 Mg 2.934 2.934 2.491 2.483 2.459 2.263 3.156 3.150 3.130 3.184 3.107 2.557 2.736 3.157 3.103 2.683 2.604 3.071 3.109 3.190 3.157 3.146 3.139 2.655 2.587 2.621 2.619 2.746 3.199 3.204 3.209 3.179 2.721 2.647 3.135 3.172 3.207 3.221 3.126 3.155 3.213 3.256 3.147 3.128 2.749 2+ Mn 0.022 0.024 0.033 0.034 0.041 0.037 0.040 0.046 0.048 0.048 0.052 0.060 0.058 0.045 0.052 0.056 0.057 0.048 0.052 0.042 0.046 0.041 0.042 0.056 0.058 0.059 0.059 0.062 0.040 0.044 0.042 0.041 0.052 0.058 0.043 0.041 0.041 0.035 0.048 0.048 0.037 0.038 0.048 0.051 0.052 2+ Fe 1.553 1.606 1.712 1.897 1.931 1.872 1.699 1.732 1.744 1.720 1.772 2.197 2.088 1.725 1.777 2.171 2.181 1.791 1.766 1.683 1.700 1.683 1.683 2.172 2.174 2.208 2.150 2.087 1.702 1.678 1.669 1.666 2.068 2.162 1.734 1.690 1.695 1.648 1.775 1.768 1.708 1.660 1.745 1.722 1.896 3+ Fe 0.274 0.284 0.302 0.335 0.341 0.330 0.257 0.235 0.228 0.216 0.250 0.335 0.287 0.241 0.236 0.263 0.282 0.245 0.241 0.258 0.270 0.283 0.295 0.288 0.319 0.277 0.295 0.253 0.237 0.271 0.237 0.264 0.309 0.289 0.247 0.265 0.272 0.248 0.246 0.205 0.263 0.253 0.237 0.271 0.334 Ti 0.703 0.687 0.612 0.636 0.619 0.627 0.536 0.520 0.525 0.520 0.499 0.520 0.473 0.516 0.524 0.481 0.520 0.530 0.528 0.515 0.523 0.508 0.525 0.503 0.519 0.511 0.519 0.491 0.515 0.486 0.519 0.507 0.492 0.494 0.536 0.509 0.491 0.513 0.506 0.513 0.491 0.493 0.504 0.508 0.465 0.062 0.037 0.266 0.088 0.125 0.226 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.030 Al(vi) (iv) 3+ 0.000 0.000 0.000 0.000 0.000 0.000 0.043 0.070 0.079 0.088 0.062 0.053 0.081 0.063 0.078 0.120 0.103 0.071 0.071 0.039 0.030 0.014 0.002 0.095 0.065 0.113 0.085 0.115 0.063 0.025 0.058 0.030 0.056 0.092 0.059 0.033 0.027 0.043 0.068 0.108 0.039 0.040 0.071 0.033 0.000 Fe 2.503 2.573 2.236 2.402 2.415 2.179 2.514 2.417 2.417 2.374 2.392 2.514 2.291 2.409 2.401 2.317 2.373 2.451 2.449 2.461 2.531 2.474 2.528 2.405 2.445 2.397 2.368 2.275 2.431 2.408 2.384 2.405 2.341 2.324 2.471 2.449 2.460 2.405 2.390 2.341 2.434 2.450 2.366 2.420 2.161 Al(iv) Si 5.497 5.427 5.764 5.598 5.585 5.821 5.443 5.512 5.504 5.537 5.546 5.433 5.628 5.527 5.521 5.562 5.524 5.478 5.480 5.500 5.439 5.512 5.470 5.500 5.490 5.491 5.548 5.610 5.506 5.568 5.558 5.565 5.603 5.584 5.470 5.518 5.512 5.552 5.542 5.552 5.526 5.511 5.563 5.547 5.839 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.835 1.849 1.839 1.777 1.790 1.750 1.738 1.756 1.746 1.783 1.731 1.724 1.757 1.766 1.768 1.767 1.660 1.654 1.728 1.713 1.747 1.741 1.720 1.719 1.702 1.721 1.710 1.744 1.760 1.771 1.728 1.723 1.778 1.653 1.671 1.672 1.806 1.777 1.815 1.775 1.805 1.814 1.769 1.675 1.777 K 1.696 1.705 1.693 1.718 1.743 1.664 1.659 1.676 1.664 1.686 1.684 1.670 1.724 1.719 1.715 1.696 1.622 1.613 1.668 1.662 1.700 1.682 1.654 1.684 1.646 1.671 1.687 1.717 1.667 1.666 1.646 1.648 1.678 1.587 1.595 1.572 1.706 1.704 1.744 1.722 1.733 1.725 1.656 1.601 1.654 Na 0.140 0.145 0.145 0.059 0.047 0.086 0.080 0.080 0.082 0.097 0.047 0.053 0.032 0.047 0.053 0.071 0.038 0.041 0.061 0.051 0.047 0.060 0.066 0.036 0.056 0.050 0.023 0.026 0.093 0.105 0.082 0.076 0.101 0.065 0.076 0.099 0.099 0.073 0.071 0.053 0.072 0.089 0.112 0.074 0.123

Oct total 5.646 5.643 5.652 5.651 5.665 5.699 5.709 5.691 5.706 5.690 5.708 5.718 5.667 5.643 5.708 5.705 5.680 5.681 5.718 5.686 5.637 5.663 5.669 5.687 5.719 5.700 5.638 5.667 5.683 5.660 5.676 5.709 5.709 5.763 5.755 5.748 5.665 5.652 5.613 5.668 5.680 5.663 5.677 5.757 5.662 Mg 2.820 2.788 2.738 2.677 2.713 3.108 3.194 3.181 3.228 3.215 3.066 3.083 2.746 2.778 2.850 2.839 3.130 3.115 2.580 2.606 2.580 2.632 2.605 2.631 3.185 3.175 2.745 2.726 3.307 3.260 2.696 2.748 3.118 3.101 3.162 3.155 3.219 3.133 2.696 2.666 3.307 3.278 3.439 3.086 3.422 2+ Mn 0.058 0.057 0.060 0.050 0.049 0.033 0.033 0.028 0.031 0.033 0.039 0.034 0.044 0.042 0.024 0.028 0.036 0.026 0.042 0.049 0.048 0.043 0.048 0.039 0.033 0.026 0.042 0.047 0.020 0.025 0.037 0.056 0.021 0.023 0.028 0.029 0.037 0.032 0.042 0.055 0.031 0.034 0.021 0.023 0.014 2+ Fe 2.060 2.071 2.103 2.098 2.093 1.718 1.664 1.666 1.660 1.661 1.771 1.770 2.092 2.007 2.036 2.037 1.650 1.684 2.223 2.154 2.125 2.132 2.147 2.161 1.675 1.674 2.034 2.080 1.572 1.577 2.139 2.150 1.752 1.792 1.753 1.764 1.655 1.664 2.100 2.150 1.637 1.637 1.458 1.839 1.459 3+ Fe 0.223 0.273 0.277 0.327 0.316 0.303 0.294 0.294 0.293 0.284 0.312 0.313 0.295 0.327 0.360 0.359 0.291 0.297 0.373 0.333 0.376 0.376 0.378 0.319 0.296 0.295 0.346 0.338 0.278 0.278 0.323 0.271 0.310 0.316 0.310 0.289 0.253 0.293 0.301 0.312 0.216 0.240 0.257 0.314 0.258 Ti 0.484 0.454 0.475 0.499 0.493 0.493 0.476 0.499 0.493 0.496 0.520 0.503 0.489 0.488 0.426 0.418 0.496 0.508 0.499 0.545 0.483 0.481 0.491 0.537 0.497 0.493 0.470 0.475 0.502 0.483 0.481 0.484 0.499 0.487 0.500 0.512 0.501 0.486 0.473 0.484 0.489 0.474 0.498 0.494 0.479 0.000 0.000 0.000 0.000 0.000 0.044 0.048 0.024 0.001 0.000 0.000 0.015 0.000 0.000 0.012 0.024 0.077 0.051 0.000 0.000 0.025 0.000 0.000 0.000 0.034 0.038 0.000 0.000 0.004 0.037 0.000 0.000 0.009 0.042 0.001 0.000 0.000 0.044 0.000 0.000 0.000 0.000 0.004 0.000 0.030 Al(vi) (iv) 3+ 0.141 0.093 0.094 0.043 0.054 0.000 0.000 0.000 0.000 0.009 0.000 0.000 0.074 0.027 0.000 0.000 0.000 0.000 0.020 0.047 0.000 0.000 0.001 0.063 0.000 0.000 0.013 0.029 0.000 0.000 0.055 0.108 0.000 0.000 0.000 0.022 0.039 0.000 0.070 0.067 0.073 0.049 0.000 0.010 0.000 Fe 2.177 2.224 2.276 2.361 2.369 2.481 2.449 2.453 2.438 2.431 2.498 2.492 2.291 2.330 2.407 2.395 2.381 2.381 2.517 2.463 2.388 2.403 2.417 2.422 2.464 2.440 2.261 2.336 2.410 2.372 2.308 2.272 2.512 2.511 2.493 2.457 2.353 2.390 2.217 2.324 2.284 2.279 2.380 2.480 2.346 Al(iv) Si 5.682 5.683 5.629 5.596 5.577 5.519 5.551 5.547 5.562 5.560 5.502 5.508 5.635 5.643 5.593 5.605 5.619 5.619 5.464 5.490 5.612 5.597 5.583 5.516 5.536 5.560 5.726 5.635 5.590 5.628 5.637 5.620 5.488 5.489 5.507 5.521 5.608 5.610 5.712 5.609 5.642 5.672 5.620 5.510 5.654 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.671 1.668 1.694 1.675 1.691 1.721 1.691 1.701 1.664 1.750 1.732 1.786 1.748 1.747 1.665 1.716 1.552 1.680 1.722 1.687 1.695 1.703 1.749 1.764 1.756 1.703 1.686 1.686 1.671 1.708 1.716 1.786 1.844 1.800 1.839 1.812 1.829 1.845 1.847 1.854 1.878 1.841 1.832 1.846 1.841 K 1.600 1.624 1.645 1.566 1.591 1.653 1.638 1.598 1.536 1.644 1.636 1.659 1.639 1.641 1.575 1.614 1.484 1.609 1.629 1.582 1.615 1.613 1.628 1.651 1.618 1.591 1.598 1.602 1.561 1.626 1.640 1.632 1.677 1.658 1.675 1.653 1.669 1.701 1.679 1.700 1.712 1.678 1.674 1.689 1.694 Na 0.071 0.044 0.050 0.109 0.099 0.068 0.053 0.102 0.128 0.105 0.096 0.126 0.108 0.106 0.090 0.103 0.067 0.071 0.093 0.105 0.080 0.091 0.120 0.113 0.138 0.112 0.089 0.084 0.110 0.081 0.076 0.155 0.168 0.142 0.164 0.160 0.161 0.144 0.167 0.154 0.166 0.163 0.158 0.157 0.147

Oct total 5.765 5.724 5.744 5.733 5.706 5.710 5.730 5.750 5.747 5.724 5.700 5.710 5.654 5.716 5.710 5.716 5.725 5.725 5.725 5.732 5.731 5.754 5.712 5.722 5.731 5.735 5.731 5.738 5.747 5.718 5.712 5.653 5.663 5.572 5.645 5.674 5.659 5.646 5.651 5.648 5.664 5.659 5.676 5.658 5.658 Mg 3.098 2.786 2.839 3.191 3.198 2.627 2.687 3.359 3.286 3.141 3.139 3.108 3.079 3.133 3.063 3.162 2.948 3.095 3.149 3.181 3.073 3.217 3.254 3.262 3.279 3.145 3.236 3.163 3.132 3.077 3.091 3.065 3.034 2.537 3.012 3.011 3.058 3.090 3.019 3.160 3.077 3.117 3.137 2.924 2.982 2+ Mn 0.039 0.049 0.045 0.019 0.013 0.044 0.046 0.023 0.027 0.035 0.032 0.031 0.027 0.028 0.034 0.019 0.019 0.026 0.031 0.032 0.035 0.033 0.023 0.021 0.022 0.028 0.021 0.032 0.030 0.036 0.035 0.045 0.039 0.043 0.029 0.044 0.041 0.037 0.043 0.040 0.037 0.037 0.043 0.046 0.054 2+ Fe 1.829 2.090 2.121 1.681 1.659 2.225 2.209 1.613 1.635 1.763 1.710 1.778 1.672 1.754 1.737 1.718 1.835 1.760 1.738 1.709 1.756 1.733 1.612 1.603 1.613 1.710 1.649 1.729 1.764 1.795 1.766 1.691 1.711 2.058 1.677 1.708 1.713 1.675 1.727 1.636 1.704 1.678 1.672 1.808 1.775 3+ Fe 0.295 0.331 0.261 0.297 0.293 0.312 0.298 0.255 0.288 0.282 0.302 0.297 0.295 0.300 0.306 0.303 0.324 0.311 0.307 0.302 0.310 0.306 0.284 0.283 0.285 0.302 0.292 0.305 0.311 0.293 0.311 0.298 0.302 0.363 0.295 0.302 0.302 0.296 0.305 0.289 0.301 0.297 0.295 0.319 0.313 Ti 0.504 0.470 0.478 0.495 0.494 0.503 0.490 0.500 0.496 0.503 0.460 0.497 0.520 0.500 0.497 0.499 0.440 0.470 0.496 0.483 0.544 0.465 0.500 0.511 0.468 0.516 0.501 0.506 0.483 0.518 0.457 0.515 0.526 0.470 0.525 0.537 0.498 0.497 0.533 0.506 0.519 0.518 0.525 0.534 0.523 0.000 0.000 0.000 0.049 0.049 0.000 0.000 0.000 0.016 0.000 0.058 0.000 0.061 0.000 0.073 0.016 0.158 0.062 0.004 0.026 0.013 0.000 0.039 0.042 0.064 0.034 0.032 0.003 0.026 0.000 0.052 0.039 0.051 0.100 0.106 0.072 0.046 0.053 0.024 0.017 0.026 0.011 0.004 0.027 0.011 Al(vi) (iv) 3+ 0.028 0.038 0.114 0.000 0.000 0.081 0.092 0.029 0.000 0.030 0.000 0.016 0.000 0.010 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.025 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 2.476 2.349 2.285 2.477 2.433 2.378 2.336 2.427 2.455 2.455 2.412 2.482 2.452 2.470 2.458 2.466 2.364 2.442 2.474 2.445 2.568 2.447 2.496 2.556 2.503 2.541 2.474 2.482 2.467 2.447 2.417 2.460 2.573 2.346 2.582 2.606 2.491 2.479 2.543 2.468 2.573 2.501 2.532 2.577 2.529 Al(iv) Si 5.496 5.613 5.601 5.523 5.567 5.541 5.572 5.544 5.545 5.515 5.588 5.502 5.548 5.520 5.542 5.534 5.636 5.558 5.526 5.555 5.432 5.553 5.504 5.444 5.497 5.459 5.526 5.518 5.533 5.529 5.583 5.540 5.427 5.654 5.418 5.394 5.509 5.521 5.457 5.532 5.427 5.499 5.468 5.423 5.471 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.781 1.842 1.788 1.841 1.824 1.857 1.842 1.858 1.818 1.838 1.840 1.821 1.823 1.840 1.830 1.773 1.805 1.832 1.740 1.792 1.699 1.664 1.801 1.741 1.834 1.814 1.782 1.783 1.740 1.759 1.785 1.794 1.822 1.806 1.742 1.835 1.809 1.829 1.818 1.804 1.819 1.796 1.805 1.789 1.825 K 1.623 1.684 1.616 1.669 1.676 1.699 1.692 1.706 1.665 1.675 1.685 1.660 1.668 1.681 1.662 1.588 1.637 1.657 1.597 1.615 1.558 1.522 1.635 1.568 1.660 1.636 1.623 1.600 1.578 1.603 1.612 1.614 1.649 1.631 1.598 1.658 1.627 1.653 1.649 1.640 1.647 1.639 1.653 1.610 1.648 Na 0.158 0.158 0.173 0.172 0.147 0.158 0.150 0.152 0.153 0.163 0.155 0.161 0.155 0.158 0.168 0.184 0.167 0.175 0.143 0.177 0.140 0.143 0.166 0.172 0.174 0.178 0.159 0.182 0.161 0.156 0.173 0.180 0.174 0.175 0.144 0.177 0.182 0.176 0.169 0.164 0.172 0.157 0.152 0.180 0.177

Oct total 5.620 5.665 5.662 5.678 5.664 5.631 5.681 5.649 5.658 5.673 5.661 5.636 5.634 5.651 5.666 5.678 5.669 5.694 5.674 5.673 5.708 5.791 5.691 5.664 5.679 5.691 5.699 5.630 5.686 5.692 5.661 5.658 5.626 5.593 5.629 5.606 5.624 5.648 5.615 5.599 5.629 5.626 5.582 5.616 5.599 Mg 3.021 3.083 3.051 3.047 3.042 3.081 3.065 2.976 2.951 3.074 3.078 3.058 3.049 3.145 3.120 3.645 3.307 3.731 3.007 3.278 3.025 3.135 3.687 3.490 3.277 3.534 3.527 3.562 3.023 3.474 3.641 3.732 3.046 3.198 2.866 3.098 3.322 3.512 3.491 3.469 3.461 3.485 3.417 3.353 3.377 2+ Mn 0.033 0.041 0.041 0.044 0.045 0.044 0.033 0.047 0.052 0.036 0.040 0.036 0.039 0.038 0.042 0.023 0.043 0.043 0.041 0.041 0.047 0.060 0.029 0.027 0.047 0.036 0.039 0.027 0.058 0.043 0.030 0.036 0.053 0.046 0.058 0.052 0.030 0.027 0.039 0.039 0.045 0.040 0.021 0.027 0.035 2+ Fe 1.655 1.707 1.691 1.721 1.700 1.640 1.721 1.780 1.789 1.715 1.687 1.679 1.683 1.628 1.673 1.247 1.570 1.231 1.794 1.533 1.784 1.826 1.264 1.351 1.615 1.414 1.384 1.276 1.746 1.405 1.205 1.134 1.726 1.534 1.801 1.653 1.465 1.364 1.308 1.297 1.377 1.353 1.336 1.414 1.386 3+ Fe 0.292 0.292 0.298 0.304 0.300 0.289 0.304 0.314 0.316 0.303 0.298 0.296 0.297 0.287 0.295 0.194 0.262 0.203 0.317 0.271 0.315 0.284 0.218 0.238 0.243 0.199 0.244 0.226 0.308 0.248 0.213 0.201 0.291 0.270 0.318 0.292 0.258 0.237 0.231 0.229 0.243 0.239 0.235 0.249 0.245 Ti 0.501 0.541 0.497 0.558 0.535 0.509 0.530 0.521 0.526 0.506 0.521 0.499 0.496 0.526 0.504 0.569 0.487 0.487 0.483 0.516 0.502 0.486 0.494 0.503 0.497 0.508 0.505 0.484 0.534 0.512 0.545 0.519 0.511 0.502 0.535 0.502 0.520 0.508 0.508 0.514 0.464 0.476 0.539 0.556 0.517 0.119 0.000 0.083 0.004 0.042 0.068 0.029 0.011 0.024 0.039 0.038 0.068 0.070 0.027 0.032 0.000 0.000 0.000 0.033 0.035 0.034 0.000 0.000 0.054 0.000 0.000 0.000 0.054 0.017 0.011 0.027 0.035 0.000 0.042 0.051 0.009 0.029 0.000 0.038 0.051 0.039 0.033 0.033 0.017 0.039 Al(vi) (iv) 3+ 0.000 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.027 0.015 0.014 0.000 0.000 0.000 0.038 0.005 0.000 0.042 0.050 0.000 0.000 0.000 0.000 0.000 0.000 0.013 0.000 0.000 0.000 0.000 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 2.432 2.537 2.488 2.621 2.565 2.494 2.598 2.524 2.525 2.536 2.539 2.456 2.451 2.507 2.495 2.432 2.364 2.382 2.403 2.475 2.468 2.464 2.383 2.367 2.386 2.360 2.432 2.291 2.505 2.426 2.438 2.384 2.374 2.309 2.440 2.353 2.385 2.374 2.332 2.311 2.289 2.272 2.317 2.401 2.339 Al(iv) Si 5.568 5.454 5.512 5.379 5.435 5.506 5.402 5.476 5.475 5.464 5.461 5.544 5.549 5.493 5.505 5.541 5.622 5.604 5.597 5.525 5.532 5.498 5.612 5.633 5.572 5.590 5.568 5.709 5.495 5.574 5.562 5.616 5.613 5.691 5.560 5.647 5.615 5.622 5.668 5.689 5.711 5.728 5.683 5.599 5.661 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.841 1.780 1.856 1.753 1.742 1.760 1.804 1.743 1.820 1.784 1.798 1.724 1.816 1.798 1.748 1.787 1.780 1.826 1.855 1.819 1.771 1.803 1.863 1.826 1.822 1.815 1.841 1.863 1.898 1.925 1.840 1.800 1.874 1.869 1.820 1.819 1.835 1.824 1.817 1.789 1.829 1.777 1.824 1.792 1.846 K 1.661 1.634 1.684 1.608 1.606 1.611 1.628 1.579 1.653 1.624 1.626 1.575 1.646 1.638 1.580 1.606 1.607 1.652 1.698 1.697 1.655 1.663 1.681 1.627 1.630 1.687 1.689 1.754 1.783 1.867 1.716 1.668 1.732 1.736 1.656 1.660 1.666 1.664 1.651 1.631 1.641 1.603 1.659 1.633 1.683 Na 0.180 0.146 0.172 0.145 0.136 0.149 0.176 0.164 0.168 0.160 0.172 0.149 0.169 0.160 0.168 0.181 0.173 0.174 0.158 0.122 0.116 0.140 0.182 0.199 0.192 0.129 0.152 0.109 0.115 0.058 0.124 0.132 0.142 0.133 0.164 0.159 0.169 0.160 0.166 0.158 0.188 0.174 0.164 0.159 0.163

Oct total 5.579 5.632 5.596 5.624 5.631 5.610 5.621 5.627 5.576 5.620 5.609 5.604 5.568 5.567 5.570 5.591 5.604 5.621 5.640 5.590 5.604 5.679 5.669 5.690 5.651 5.671 5.655 5.644 5.625 5.628 5.621 5.664 5.639 5.629 5.656 5.671 5.663 5.659 5.632 5.642 5.660 5.682 5.662 5.667 5.663 Mg 3.322 2.807 3.076 2.757 3.110 3.014 3.087 2.793 3.214 3.234 3.357 2.921 2.996 3.238 3.146 3.121 3.194 3.085 3.157 2.924 2.985 3.115 3.044 3.331 3.196 3.054 3.087 3.079 3.298 3.389 3.050 3.114 3.110 3.089 3.166 3.163 3.194 3.140 2.847 2.883 3.169 3.116 3.159 3.129 3.231 2+ Mn 0.030 0.057 0.048 0.058 0.053 0.056 0.053 0.060 0.038 0.042 0.041 0.060 0.057 0.027 0.035 0.031 0.036 0.029 0.028 0.038 0.038 0.034 0.033 0.031 0.027 0.040 0.037 0.023 0.020 0.020 0.034 0.026 0.036 0.037 0.030 0.029 0.033 0.033 0.050 0.050 0.028 0.027 0.032 0.035 0.026 2+ Fe 1.417 1.875 1.674 1.865 1.616 1.624 1.666 1.825 1.477 1.522 1.398 1.726 1.664 1.455 1.536 1.550 1.500 1.605 1.591 1.740 1.686 1.702 1.786 1.514 1.543 1.715 1.691 1.711 1.486 1.480 1.671 1.671 1.674 1.671 1.610 1.627 1.623 1.624 1.851 1.822 1.609 1.662 1.628 1.652 1.597 3+ Fe 0.250 0.331 0.281 0.329 0.285 0.287 0.294 0.323 0.260 0.268 0.246 0.304 0.293 0.257 0.271 0.273 0.265 0.284 0.281 0.307 0.298 0.300 0.304 0.268 0.273 0.303 0.298 0.297 0.262 0.232 0.295 0.295 0.295 0.295 0.284 0.287 0.265 0.287 0.237 0.241 0.282 0.293 0.284 0.291 0.264 Ti 0.536 0.528 0.519 0.546 0.528 0.555 0.508 0.559 0.518 0.517 0.524 0.534 0.495 0.518 0.510 0.578 0.561 0.508 0.495 0.524 0.502 0.507 0.502 0.531 0.510 0.517 0.517 0.533 0.514 0.507 0.506 0.489 0.523 0.515 0.557 0.563 0.549 0.550 0.648 0.646 0.572 0.552 0.560 0.556 0.544 0.025 0.033 0.000 0.070 0.040 0.075 0.013 0.067 0.069 0.037 0.043 0.059 0.062 0.071 0.071 0.038 0.048 0.110 0.088 0.057 0.096 0.020 0.000 0.015 0.102 0.043 0.025 0.000 0.044 0.000 0.065 0.069 0.001 0.022 0.009 0.000 0.000 0.024 0.000 0.000 0.000 0.034 0.000 0.003 0.000 Al(vi) (iv) 3+ 0.000 0.000 0.015 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.011 0.000 0.000 0.000 0.000 0.005 0.000 0.030 0.000 0.000 0.000 0.000 0.000 0.000 0.021 0.000 0.090 0.080 0.002 0.000 0.004 0.000 0.018 Fe 2.346 2.463 2.352 2.492 2.385 2.452 2.368 2.506 2.338 2.363 2.353 2.364 2.296 2.296 2.251 2.436 2.423 2.478 2.494 2.412 2.376 2.495 2.497 2.549 2.519 2.538 2.508 2.510 2.482 2.396 2.454 2.470 2.494 2.475 2.541 2.574 2.503 2.552 2.525 2.527 2.574 2.571 2.547 2.534 2.505 Al(iv) Si 5.654 5.537 5.633 5.508 5.615 5.548 5.632 5.494 5.662 5.637 5.647 5.636 5.704 5.704 5.749 5.564 5.577 5.522 5.506 5.588 5.624 5.505 5.492 5.451 5.481 5.462 5.492 5.485 5.518 5.574 5.546 5.530 5.506 5.525 5.459 5.426 5.476 5.448 5.385 5.393 5.424 5.429 5.449 5.466 5.476 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.810 1.778 1.834 1.777 1.815 1.802 1.818 1.778 1.820 1.819 1.797 1.820 1.819 1.835 1.824 1.817 1.789 1.829 1.777 1.824 1.792 1.846 1.810 1.778 1.834 1.777 1.815 1.802 1.818 1.778 1.820 1.819 1.797 1.891 1.879 1.837 1.881 1.845 1.705 1.669 1.833 1.797 1.769 1.784 1.862 K 1.636 1.608 1.642 1.594 1.619 1.636 1.643 1.601 1.653 1.652 1.628 1.656 1.660 1.666 1.664 1.651 1.631 1.641 1.603 1.659 1.633 1.683 1.636 1.608 1.642 1.594 1.619 1.636 1.643 1.601 1.653 1.652 1.628 1.707 1.685 1.633 1.737 1.706 1.583 1.546 1.697 1.661 1.628 1.649 1.714 Na 0.173 0.170 0.192 0.182 0.196 0.166 0.175 0.177 0.167 0.167 0.169 0.164 0.159 0.169 0.160 0.166 0.158 0.188 0.174 0.164 0.159 0.163 0.173 0.170 0.192 0.182 0.196 0.166 0.175 0.177 0.167 0.167 0.169 0.184 0.193 0.205 0.144 0.138 0.122 0.123 0.136 0.135 0.142 0.136 0.148

Oct total 5.680 5.674 5.645 5.670 5.676 5.670 5.673 5.697 5.661 5.685 5.671 5.656 5.671 5.663 5.659 5.632 5.642 5.660 5.682 5.662 5.667 5.663 5.680 5.674 5.645 5.670 5.676 5.670 5.673 5.697 5.661 5.685 5.671 5.618 5.573 5.537 5.677 5.635 5.660 5.678 5.660 5.670 5.675 5.672 5.623 Mg 3.170 3.209 3.255 3.154 3.220 3.182 3.246 3.083 3.073 3.243 3.245 3.166 3.163 3.194 3.140 2.847 2.883 3.169 3.116 3.159 3.129 3.231 3.170 3.209 3.255 3.154 3.220 3.182 3.246 3.083 3.073 3.243 3.245 2.585 2.746 2.072 3.039 2.966 2.913 2.869 3.032 3.021 3.029 2.998 2.672 2+ Mn 0.030 0.024 0.029 0.027 0.023 0.027 0.029 0.030 0.033 0.031 0.030 0.030 0.029 0.033 0.033 0.050 0.050 0.028 0.027 0.032 0.035 0.026 0.030 0.024 0.029 0.027 0.023 0.027 0.029 0.030 0.033 0.031 0.030 0.040 0.043 0.032 0.082 0.080 0.048 0.050 0.079 0.073 0.080 0.083 0.053 2+ Fe 1.633 1.583 1.528 1.597 1.573 1.596 1.581 1.720 1.698 1.604 1.576 1.610 1.627 1.623 1.624 1.851 1.822 1.609 1.662 1.628 1.652 1.597 1.633 1.583 1.528 1.597 1.573 1.596 1.581 1.720 1.698 1.604 1.576 2.152 1.939 2.481 1.832 1.794 1.821 1.866 1.787 1.788 1.789 1.809 2.084 3+ Fe 0.286 0.263 0.263 0.282 0.277 0.282 0.273 0.282 0.287 0.251 0.244 0.284 0.287 0.265 0.287 0.237 0.241 0.282 0.293 0.284 0.291 0.264 0.286 0.263 0.263 0.282 0.277 0.282 0.273 0.282 0.287 0.251 0.244 0.211 0.260 0.360 0.279 0.316 0.321 0.330 0.300 0.315 0.315 0.319 0.326 Ti 0.561 0.595 0.570 0.600 0.576 0.570 0.544 0.581 0.569 0.555 0.576 0.557 0.563 0.549 0.550 0.648 0.646 0.572 0.552 0.560 0.556 0.544 0.561 0.595 0.570 0.600 0.576 0.570 0.544 0.581 0.569 0.555 0.576 0.631 0.585 0.592 0.444 0.445 0.547 0.542 0.461 0.470 0.441 0.458 0.489 0.000 0.000 0.000 0.011 0.008 0.013 0.000 0.000 0.000 0.000 0.000 0.009 0.000 0.000 0.024 0.000 0.000 0.000 0.034 0.000 0.003 0.000 0.000 0.000 0.000 0.011 0.008 0.013 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.033 0.010 0.020 0.000 0.003 0.022 0.004 0.000 Al(vi) (iv) 3+ 0.003 0.016 0.006 0.000 0.000 0.000 0.005 0.021 0.013 0.032 0.035 0.000 0.000 0.021 0.000 0.090 0.080 0.002 0.000 0.004 0.000 0.018 0.003 0.016 0.006 0.000 0.000 0.000 0.005 0.021 0.013 0.032 0.035 0.168 0.082 0.077 0.044 0.000 0.000 0.000 0.016 0.000 0.000 0.000 0.043 Fe 2.573 2.563 2.522 2.609 2.603 2.577 2.521 2.594 2.554 2.519 2.499 2.541 2.574 2.503 2.552 2.525 2.527 2.574 2.571 2.547 2.534 2.505 2.573 2.563 2.522 2.609 2.603 2.577 2.521 2.594 2.554 2.519 2.499 2.432 2.371 2.379 2.359 2.354 2.448 2.458 2.359 2.395 2.339 2.367 2.367 Al(iv) Si 5.424 5.421 5.471 5.391 5.397 5.423 5.474 5.385 5.433 5.449 5.466 5.459 5.426 5.476 5.448 5.385 5.393 5.424 5.429 5.449 5.466 5.476 5.424 5.421 5.471 5.391 5.397 5.423 5.474 5.385 5.433 5.449 5.466 5.399 5.547 5.544 5.597 5.646 5.552 5.542 5.626 5.605 5.661 5.633 5.590 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Alk total 1.710 1.789 1.826 1.723 1.687 1.861 1.855 1.835 1.742 1.857 1.840 1.873 1.847 1.770 1.807 1.856 1.858 1.856 1.847 1.795 1.849 1.853 1.828 1.879 1.877 1.831 1.853 1.831 1.833 1.822 1.878 1.862 1.737 1.718 1.589 1.640 1.758 1.823 1.826 1.717 1.699 1.685 1.797 1.768 1.766 1.714 K 1.576 1.650 1.676 1.583 1.557 1.694 1.704 1.684 1.603 1.716 1.686 1.719 1.699 1.631 1.650 1.715 1.709 1.732 1.708 1.670 1.705 1.711 1.678 1.735 1.738 1.695 1.712 1.684 1.692 1.666 1.725 1.718 1.603 1.564 1.459 1.530 1.596 1.648 1.657 1.609 1.574 1.560 1.681 1.616 1.635 1.585 Na 0.135 0.139 0.150 0.140 0.130 0.168 0.151 0.151 0.139 0.141 0.154 0.154 0.148 0.139 0.157 0.140 0.149 0.123 0.139 0.125 0.145 0.142 0.150 0.144 0.139 0.136 0.141 0.147 0.141 0.156 0.153 0.144 0.134 0.154 0.130 0.110 0.162 0.175 0.169 0.108 0.125 0.125 0.116 0.152 0.130 0.128

Oct total 5.618 5.655 5.685 5.711 5.694 5.641 5.650 5.630 5.676 5.673 5.638 5.664 5.682 5.641 5.687 5.620 5.640 5.646 5.658 5.621 5.619 5.627 5.635 5.685 5.663 5.658 5.653 5.652 5.665 5.539 5.632 5.641 5.526 5.537 5.354 5.457 5.564 5.574 5.581 5.471 5.442 5.382 5.479 5.441 5.473 5.478 Mg 2.664 2.781 2.974 3.061 2.729 2.599 2.676 2.681 2.623 2.573 2.606 2.954 3.002 2.512 2.556 3.063 3.100 3.085 3.029 2.990 3.051 3.098 3.093 3.072 3.032 3.043 3.046 3.025 3.084 2.933 2.991 2.984 2.304 2.310 1.927 2.835 2.510 3.015 2.988 1.934 1.967 2.451 2.552 2.927 2.970 2.814 2+ Mn 0.046 0.060 0.046 0.045 0.050 0.057 0.059 0.052 0.053 0.064 0.053 0.046 0.054 0.057 0.050 0.025 0.020 0.023 0.027 0.016 0.029 0.025 0.026 0.023 0.028 0.026 0.025 0.025 0.024 0.018 0.031 0.026 0.022 0.018 0.021 0.015 0.027 0.010 0.015 0.026 0.020 0.019 0.017 0.016 0.011 0.022 2+ Fe 2.021 2.034 1.822 1.762 2.069 2.155 2.103 2.061 2.133 2.188 2.151 1.833 1.810 2.146 2.218 1.736 1.748 1.753 1.787 1.767 1.732 1.727 1.734 1.783 1.788 1.778 1.767 1.788 1.760 1.698 1.809 1.829 2.037 1.994 1.818 1.276 1.937 1.582 1.622 2.242 2.127 1.511 1.755 1.304 1.349 1.450 3+ Fe 0.356 0.315 0.307 0.311 0.356 0.325 0.308 0.360 0.368 0.334 0.345 0.300 0.288 0.379 0.349 0.261 0.247 0.272 0.284 0.282 0.270 0.249 0.259 0.314 0.298 0.290 0.269 0.278 0.279 0.300 0.289 0.267 0.359 0.352 0.321 0.225 0.342 0.279 0.286 0.395 0.375 0.267 0.310 0.230 0.238 0.256 Ti 0.446 0.465 0.536 0.506 0.490 0.505 0.503 0.476 0.499 0.514 0.482 0.532 0.527 0.492 0.514 0.535 0.525 0.513 0.532 0.565 0.537 0.528 0.522 0.488 0.516 0.520 0.545 0.536 0.519 0.503 0.511 0.534 0.591 0.582 0.491 0.506 0.528 0.614 0.593 0.543 0.534 0.495 0.587 0.594 0.661 0.456 0.085 0.000 0.000 0.026 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.055 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.000 0.000 0.000 0.000 0.000 0.087 0.000 0.000 0.213 0.281 0.775 0.600 0.220 0.074 0.077 0.330 0.419 0.639 0.259 0.370 0.245 0.479 Al(vi) (iv) 3+ 0.000 0.044 0.014 0.000 0.009 0.055 0.063 0.003 0.008 0.053 0.035 0.024 0.032 0.000 0.043 0.045 0.061 0.037 0.032 0.031 0.035 0.056 0.046 0.000 0.017 0.023 0.043 0.038 0.032 0.000 0.030 0.057 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 2.279 2.301 2.562 2.493 2.403 2.423 2.406 2.403 2.453 2.512 2.389 2.543 2.520 2.469 2.515 2.381 2.374 2.408 2.479 2.418 2.395 2.356 2.355 2.545 2.517 2.455 2.477 2.446 2.448 2.292 2.423 2.422 2.545 2.590 2.374 2.391 2.503 2.551 2.535 2.472 2.445 2.345 2.499 2.438 2.516 2.316 Al(iv) Si 5.721 5.655 5.423 5.507 5.588 5.522 5.531 5.594 5.539 5.435 5.576 5.434 5.449 5.531 5.442 5.573 5.565 5.555 5.489 5.551 5.570 5.588 5.599 5.455 5.466 5.522 5.481 5.516 5.520 5.708 5.547 5.521 5.455 5.410 5.626 5.609 5.497 5.449 5.465 5.528 5.555 5.655 5.501 5.562 5.484 5.684 Structural Formulas (in Atoms) of Biotite in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) of Biotite in Samples Tertiary

Appendix 5 85 Total 99.98 99.85 98.90 97.38 96.85 96.72 96.85 97.22 97.98 97.42 98.02 96.57 96.67 97.87 96.93 97.34 96.80 98.16 98.24 97.54 97.86 97.77 98.07 97.55 97.72 97.29 97.73 98.49 97.95 98.19 97.76 97.51 98.05 98.12 97.80 98.13 98.00 98.33 98.74 98.27 97.81 98.71 99.53 97.93 97.89 97.61 98.33 FeO 11.75 11.73 11.68 11.72 11.31 11.84 11.92 16.87 16.37 16.85 13.65 13.09 16.56 16.53 17.54 17.64 16.62 16.40 17.02 17.09 17.99 17.59 18.17 18.21 12.73 16.57 16.37 17.45 16.74 16.77 17.59 17.27 16.52 16.30 18.21 16.73 14.97 17.70 16.73 18.35 12.75 12.35 16.37 16.77 12.35 18.16 17.46 0.43 0.42 0.43 0.26 0.17 0.34 0.33 0.80 0.84 0.97 1.05 0.30 0.35 1.02 1.00 1.00 1.00 0.76 0.82 0.00 0.86 0.32 0.84 0.96 0.07 0.16 0.95 0.95 0.99 0.92 0.71 0.61 0.56 0.79 1.01 0.91 0.91 0.95 1.05 0.37 0.25 0.90 0.97 0.22 0.22 0.87 0.87 MnO 2 SiO 42.69 43.64 43.31 42.21 42.18 42.91 43.29 47.19 48.37 46.36 46.79 42.62 42.69 46.73 46.54 46.55 46.20 47.13 47.36 46.97 47.06 43.57 48.38 48.21 42.35 41.79 45.45 48.45 47.83 45.87 44.77 42.38 43.03 45.85 46.44 48.17 45.16 47.78 47.44 43.27 42.67 48.26 48.37 43.86 44.15 44.08 47.13 3 O 2 6.06 5.62 6.71 6.36 6.56 6.27 6.47 6.40 6.57 6.41 7.08 6.53 6.21 5.69 8.23 6.25 6.36 8.42 8.99 8.26 7.37 6.19 8.10 6.43 6.55 6.11 6.39 9.23 6.90 Al 11.66 11.31 11.70 11.41 11.45 11.42 11.24 11.49 10.84 10.55 10.33 10.33 10.23 10.89 12.57 12.37 10.13 10.21 NiO 0.00 0.00 0.02 0.00 0.03 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 2.69 2.56 2.30 2.61 2.58 2.64 2.41 0.96 0.77 1.19 1.20 2.86 2.73 1.20 1.27 1.21 1.22 1.16 1.13 1.29 1.24 2.33 1.18 1.05 3.11 3.29 1.33 1.05 1.00 1.61 1.46 2.18 2.33 1.26 1.31 1.30 1.56 1.26 1.11 2.77 2.97 1.27 1.33 2.91 3.22 1.73 1.16 TiO CaO 11.36 11.43 11.31 11.27 11.18 11.10 11.21 11.21 11.43 11.30 11.19 11.29 11.26 11.02 10.98 10.96 10.67 10.65 10.42 10.51 10.63 10.57 10.48 10.42 10.68 10.73 10.59 10.46 10.60 10.63 10.55 10.49 10.46 10.42 10.69 10.81 10.89 10.48 10.70 10.93 10.82 10.65 10.40 10.86 10.90 10.52 10.56 MgO 11.40 11.70 11.82 11.73 11.78 11.27 11.47 11.19 11.17 11.98 11.26 11.71 11.97 10.79 10.90 10.78 12.06 12.60 13.98 14.17 12.38 12.82 14.06 14.11 12.19 12.17 12.01 13.67 12.37 12.81 13.71 13.37 12.52 12.46 10.99 10.67 10.60 10.96 13.61 12.42 13.46 13.58 12.95 12.75 14.01 13.98 10.25 O 2 K 0.82 0.76 0.77 0.74 0.77 0.97 0.95 0.58 0.53 0.70 0.61 0.98 0.98 0.63 0.62 0.62 0.67 0.59 0.63 0.67 0.57 0.98 0.54 0.50 0.93 0.93 0.76 0.57 0.56 0.65 0.80 0.77 0.74 0.69 0.67 0.59 0.74 0.63 0.61 1.02 0.98 0.59 0.63 1.02 1.01 0.84 0.67 Cl 0.06 0.06 0.07 0.04 0.02 0.04 0.04 0.11 0.09 0.11 0.11 0.02 0.04 0.10 0.10 0.12 0.11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 2.28 2.32 2.13 2.53 2.54 2.33 2.33 1.57 1.42 1.69 1.66 2.35 2.33 1.70 1.67 1.69 1.58 1.50 1.56 1.51 1.46 2.06 1.37 1.34 2.24 2.23 1.81 1.46 1.52 1.73 1.89 2.14 2.18 1.62 1.57 1.47 1.76 1.49 1.53 2.19 2.24 1.40 1.42 2.16 2.16 1.94 1.61 Na F 0.33 0.09 0.10 0.31 0.28 0.20 0.33 0.35 0.35 0.34 0.39 0.25 0.27 0.52 0.31 0.37 0.40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Probe sample no. 06HF1 06HF2 06HF3 169HAB1 169HAB2 169HE1 169HE2 169HF1 169HF2 169HH1 169HH2 169HQ1 169HQ2 169HS1 169HS2 169HW1 169HW2 197HA1 197HA2 197HA3 197HA4 197HAE1 197HAF1h 197HAF2h 197HB1 197HB2 197HG1 197HG2 197HG2r 197HG3 197HH1 197HH2 197HH2r 197HH3 197HK1 197HK2 197HP1 197HT1 197HV1 197HW1 197HW2 199HAA1 199HAA2 199HAG1 199HAG2 199HAJ1 199HAJ2 Unit Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Compositions (in Weight Percent) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Amphiboles in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 Appendix 5. 86 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Total 98.55 98.02 97.42 97.26 97.27 96.90 96.46 96.12 96.25 95.64 97.09 96.13 97.96 98.63 96.47 96.65 95.39 96.18 96.62 96.07 96.77 96.71 96.56 98.84 96.50 98.69 96.01 96.44 98.49 95.63 95.63 96.45 99.04 96.14 99.09 98.70 97.94 98.91 99.48 98.66 99.08 99.79 99.77 99.32 98.33 98.55 98.54 FeO 11.91 11.45 11.26 11.98 11.88 18.95 16.60 16.45 13.40 17.45 16.91 16.75 16.28 16.55 16.67 12.19 17.68 18.27 16.02 16.30 15.35 14.09 12.06 17.06 17.97 17.74 16.64 17.64 12.03 12.11 12.07 15.97 16.09 16.04 17.30 17.56 16.49 16.62 18.47 17.29 17.40 18.49 17.07 16.82 16.51 16.61 14.69 0.78 0.94 0.85 0.24 0.93 1.01 0.96 0.94 1.04 1.05 0.19 0.37 0.92 0.84 0.54 0.59 0.09 0.05 0.58 0.31 0.18 0.20 0.73 0.85 0.72 0.93 0.81 0.22 0.27 0.30 0.24 0.43 0.52 0.42 0.93 0.82 0.94 0.98 0.90 0.98 1.00 0.94 0.95 1.14 0.96 1.02 0.90 MnO 2 SiO 42.72 47.96 47.68 41.72 46.75 46.67 45.84 46.25 46.12 45.36 42.40 42.36 45.72 45.31 41.65 41.46 40.39 41.26 40.60 41.73 42.44 42.59 47.58 45.76 45.15 48.73 44.54 42.71 42.74 42.67 42.44 41.76 42.81 41.46 45.77 43.28 46.77 47.52 41.40 45.43 46.15 43.29 45.52 47.96 47.29 47.24 47.72 3 O 2 5.87 5.91 6.19 6.12 6.31 6.07 6.28 6.40 7.88 8.32 6.31 7.97 7.47 5.43 7.52 8.25 7.00 6.81 7.94 7.50 8.98 6.30 6.84 6.79 6.76 Al 11.63 11.11 11.01 11.26 11.19 11.25 11.34 10.42 10.55 10.75 12.05 12.04 12.41 10.69 10.37 10.48 10.34 10.90 10.26 10.26 12.12 10.30 NiO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 2 2.11 1.08 1.13 2.59 1.16 1.21 1.31 1.06 1.18 1.26 2.67 2.33 1.36 1.59 2.38 2.35 2.94 2.97 2.33 2.70 2.95 3.10 0.94 1.35 1.21 0.86 1.36 2.75 3.35 2.69 2.77 2.50 2.55 2.33 1.57 2.45 1.33 1.33 2.36 1.48 1.36 2.00 1.50 1.07 1.31 1.35 1.40 TiO CaO 11.42 11.21 11.03 11.05 11.22 11.20 11.16 11.08 11.30 11.41 11.03 11.02 11.03 11.04 11.28 11.04 11.21 11.07 10.85 10.76 10.73 10.99 10.53 10.46 10.76 10.69 10.63 10.53 10.77 10.85 10.80 10.72 10.13 10.93 10.59 10.84 10.74 10.97 10.95 10.92 10.78 10.78 10.89 10.71 10.87 10.82 10.72 9.73 9.91 9.27 MgO 11.25 11.06 11.80 11.18 11.32 11.12 11.43 11.51 11.44 11.24 11.81 11.41 11.98 11.32 11.94 12.76 12.63 13.50 12.27 12.48 12.46 12.82 12.41 12.26 14.21 14.05 10.77 10.78 14.08 14.30 10.76 12.01 13.78 13.75 13.00 13.75 13.73 13.76 13.55 12.04 10.22 12.55 12.22 13.33 O 2 K 0.92 0.59 0.59 0.92 0.57 0.58 0.63 0.62 0.62 0.62 0.97 0.97 0.76 0.86 0.72 0.73 0.84 0.82 0.77 0.67 0.98 0.93 0.56 0.71 0.68 0.47 0.69 0.90 1.03 0.93 0.95 0.72 0.80 0.75 0.79 0.89 0.67 0.64 0.77 0.76 0.67 0.91 0.80 0.59 0.68 0.62 0.62 Cl 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.00 0.10 0.00 0.00 0.04 0.00 0.00 0.00 0.03 0.00 0.12 0.08 0.11 0.11 0.06 0.13 0.14 0.12 0.12 0.12 0.10 0.11 0.09 O 2 2.06 1.45 1.44 2.27 1.42 1.47 1.44 1.40 1.41 1.49 2.22 2.09 1.62 1.82 2.34 2.38 2.33 2.28 2.65 2.50 2.19 2.11 1.44 1.72 1.62 1.36 1.60 2.09 2.24 2.06 2.11 2.34 2.44 2.40 1.86 2.26 1.65 1.63 2.51 1.87 1.71 2.22 1.85 1.53 1.52 1.53 1.57 Na F 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.32 0.00 0.34 0.00 0.00 0.23 0.00 0.00 0.00 0.37 0.00 0.34 0.16 0.39 0.42 0.35 0.49 0.47 0.27 0.45 0.37 0.37 0.34 0.40

Probe 199HAJ3 199HAK1 199HAK2 199HD1 199HG1 199HG2 199HJ1 199HJ2 199HK1 199HK2 199HS1 199HS2 199HT1 199HT2 203HAC1 203HAC2 203HAD1 203HAD2 203HAE1 203HAE2 203HD1 203HD2 203HS1 203HS1 203HS2 203HS2 203HS3r 203HT1 203HT1 203HT2 203HT3 203HV1 203HV1 203HV2 204HAA1 204HAA2 204HAD1 204HAE1 204HE1 204HK1 204HK2 204HL1 204HL2 204HR1 204HT1 204HT2 204HV1 sample no. Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Compositions (in Weight Percent) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Amphiboles in Samples Tertiary Compositions (in Weight

Original sample no. DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 Appendix 5. Appendix 5 87 Total 99.00 98.84 98.67 99.47 99.13 98.26 95.97 97.59 97.38 99.59 99.03 98.11 97.89 99.07 98.63 97.74 98.06 98.44 98.19 98.27 98.96 99.02 97.68 97.16 97.45 97.74 96.89 95.88 96.62 97.00 97.04 97.63 96.86 96.23 96.10 96.33 96.18 97.42 95.63 96.46 96.07 95.95 96.01 99.04 99.47 99.57 98.80 9.87 FeO 11.71 11.91 11.05 15.73 15.66 13.61 18.15 17.95 14.23 14.31 15.91 15.92 12.17 12.88 13.02 13.45 14.26 14.68 14.86 15.77 17.17 17.87 15.39 18.85 17.39 16.86 18.77 16.68 17.30 16.68 14.07 13.50 16.24 16.06 16.02 12.06 12.56 12.80 12.68 13.00 12.28 13.09 21.18 18.41 18.10 14.56 0.94 0.94 0.54 0.67 0.70 0.39 0.72 0.12 0.14 0.93 1.00 0.24 0.27 0.66 0.85 0.33 0.30 0.65 0.80 0.83 0.78 0.65 0.71 0.95 0.85 0.76 0.38 0.14 0.08 0.65 0.57 0.48 0.40 0.74 0.77 0.78 0.37 0.45 0.30 0.26 0.13 0.14 0.18 1.00 0.50 0.45 0.86 MnO 2 SiO 47.29 47.28 42.98 42.88 42.48 42.43 45.11 42.99 42.45 41.79 42.24 42.91 42.48 42.12 41.91 46.27 45.53 42.08 44.28 41.22 41.10 41.92 41.97 47.36 46.83 41.97 42.03 41.85 42.92 43.63 43.86 44.64 43.38 46.62 46.96 47.05 42.89 44.07 41.93 42.32 40.55 40.69 42.33 46.04 45.64 46.51 46.75 3 O 2 6.93 6.84 7.66 8.25 8.77 8.89 6.09 6.62 9.04 9.17 9.98 6.19 5.95 5.92 9.78 9.67 6.52 8.18 7.69 7.54 Al 11.42 11.26 11.30 11.46 11.27 11.19 11.07 11.55 11.78 11.62 11.15 11.30 11.83 11.93 11.20 11.42 12.63 12.71 10.91 10.24 10.66 10.70 12.03 10.82 10.15 12.17 12.29 NiO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.01 0.01 0.01 0.04 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.00 0.03 0.00 2 1.50 1.52 2.50 2.01 2.11 2.66 1.49 2.06 1.95 3.03 2.88 3.72 3.55 3.91 2.86 1.92 2.08 3.13 2.05 2.62 2.63 3.19 2.02 1.07 1.35 2.25 2.26 2.28 2.14 1.63 1.59 1.79 2.20 0.99 0.96 0.95 2.33 2.34 2.05 2.20 3.31 3.49 2.98 1.51 1.52 1.21 1.57 TiO 9.98 CaO 11.14 11.08 11.47 11.07 11.23 11.01 11.35 11.31 11.02 11.11 11.28 11.23 11.44 11.33 11.13 11.26 11.10 11.00 11.12 11.26 11.02 11.02 11.08 11.08 11.07 11.08 11.55 10.83 10.99 10.77 10.17 10.40 10.61 10.75 10.82 10.95 10.59 10.46 10.54 10.99 10.99 10.52 10.63 10.83 10.67 10.73 9.94 9.97 9.93 9.95 9.56 9.45 9.49 MgO 11.97 11.49 11.75 11.09 11.20 11.80 12.67 12.78 12.55 12.15 12.65 15.19 13.82 10.74 10.70 12.84 12.62 12.40 12.84 12.41 10.74 10.76 12.00 10.26 13.84 14.47 10.64 12.70 12.35 12.33 12.32 12.44 13.93 13.66 13.27 13.17 12.47 12.82 13.08 13.27 O 2 K 0.69 0.73 0.98 0.94 0.95 0.79 0.77 0.61 0.59 0.81 0.80 0.83 0.82 0.78 1.00 0.69 0.74 0.85 0.90 0.99 0.85 0.83 1.09 0.59 0.59 0.93 1.32 0.70 0.72 0.94 0.86 0.63 0.71 0.56 0.55 0.54 0.93 0.98 0.79 0.82 0.81 0.78 0.91 0.68 0.89 0.80 0.76 Cl 0.08 0.10 0.04 0.07 0.08 0.06 0.07 0.02 0.02 0.06 0.06 0.04 0.02 0.02 0.04 0.07 0.07 0.03 0.07 0.08 0.06 0.03 0.23 0.12 0.10 0.09 0.07 0.02 0.03 0.11 0.08 0.06 0.05 0.10 0.10 0.08 0.04 0.05 0.05 0.04 0.02 0.03 0.07 0.17 0.16 0.14 0.08 O 2 1.64 1.61 2.27 2.22 2.17 2.39 1.62 2.45 2.38 2.58 2.43 2.42 2.43 2.39 2.42 1.71 1.82 2.45 1.85 2.42 2.37 2.42 2.01 1.40 1.54 2.10 2.07 2.10 2.10 1.73 1.75 1.94 2.11 1.55 1.61 1.59 2.21 2.13 2.35 2.37 2.54 2.42 2.29 1.88 1.56 1.50 1.54 Na F 0.39 0.31 0.31 0.28 0.20 0.69 0.75 0.27 0.30 1.46 0.99 0.46 0.53 0.72 1.01 0.41 0.52 0.78 1.00 0.88 0.94 0.75 0.21 0.23 0.29 0.15 0.37 0.18 0.24 0.30 0.38 0.25 0.26 0.33 0.36 0.42 0.27 0.42 0.38 0.56 0.24 0.34 0.68 0.60 0.34 0.26 0.32

Probe 204HV2 204HW1 204HW2 204HZ1 204HZ2 21HJ1 21HJ2 21HK1 21HK2 21HL1 21HL2 21HN1 21HN2 24HB1 24HB2 24HJ1 24HJ2 24HQ1 24HQ2 24HS1 24HS2 24HT1 34HA1 34HA2 34HB1 34HB2 34HC1 34HD1 34HD2 34HE1 34HE2 34HP1 34HP2 44HG1 44HG2 44HH1 44HJ1 44HJ2 52HA1 52HA2 52HK1 52HK2 52HP1 913HF1 919HC1 919HC2 919HE1 sample no. Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, Tuff Bates Mountain Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Compositions (in Weight Percent) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Amphiboles in Samples Tertiary Compositions (in Weight

Original sample no. DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-91-3 DRS-91-19 DRS-91-19 DRS-91-19 Appendix 5. 88 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Total 99.29 99.33 98.68 99.24 99.26 98.95 99.18 99.54 99.22 99.44 99.74 98.98 98.21 98.86 98.46 99.23 99.13 98.90 98.83 99.36 99.55 98.79 98.85 98.92 99.33 98.55 97.90 99.32 99.00 98.40 97.89 98.80 98.52 99.27 98.92 98.33 98.40 98.54 98.76 98.85 99.10 98.52 98.75 98.68 98.30 98.39 98.43 FeO 13.29 14.51 13.64 17.37 17.11 17.29 18.02 17.96 17.03 17.69 18.43 18.81 17.28 16.85 16.80 17.27 19.06 17.14 16.89 17.02 18.97 17.62 16.77 17.00 17.25 16.39 16.14 14.66 14.34 15.28 14.37 14.91 14.48 15.22 14.83 13.16 13.10 15.77 14.51 14.39 14.14 13.16 12.64 13.08 14.09 13.35 13.96 0.48 0.57 0.56 1.04 1.09 0.91 0.75 0.98 1.00 0.98 0.95 0.89 0.99 0.95 1.04 0.68 0.95 0.98 1.02 0.93 0.85 0.77 0.90 1.05 1.06 0.93 0.94 0.36 0.45 0.45 0.43 0.35 0.44 0.46 0.41 0.21 0.27 0.37 0.40 0.40 0.45 0.24 0.19 0.22 0.32 0.21 0.20 MnO 2 SiO 44.71 43.72 47.26 48.41 48.17 45.81 42.27 45.34 47.06 47.43 45.48 42.07 46.57 47.18 46.66 41.94 43.35 46.79 46.99 47.43 42.30 42.27 47.29 47.06 46.98 47.97 48.18 42.98 44.78 42.87 44.80 42.12 42.44 43.34 45.22 43.07 42.62 42.04 44.20 45.12 46.57 44.99 45.44 43.67 44.19 43.03 42.98 3 O 2 9.82 7.59 5.80 6.03 7.89 8.46 6.83 6.78 8.19 7.02 6.47 6.93 9.45 6.96 6.69 6.78 6.81 6.88 7.05 5.93 6.21 9.96 8.94 8.95 9.34 8.55 9.93 9.65 Al 11.11 11.63 11.02 11.89 11.86 11.06 11.49 11.63 11.16 11.35 11.27 10.40 10.64 10.69 12.00 10.73 10.76 10.48 10.50 NiO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.02 0.00 0.01 0.00 0.03 0.00 0.00 0.02 2 2.58 2.86 1.61 1.12 1.09 1.61 2.88 1.66 1.28 1.24 1.53 2.33 1.23 1.22 1.21 2.42 1.68 1.26 1.24 1.33 2.18 2.33 1.28 1.36 1.32 1.15 1.12 2.24 1.99 2.40 1.91 2.63 2.24 2.47 1.79 3.31 3.19 2.61 2.01 1.99 1.63 2.27 2.53 2.56 1.98 2.66 2.52 TiO CaO 11.74 11.76 11.53 11.04 11.40 11.04 11.37 11.18 11.10 11.17 11.42 11.44 11.27 11.30 11.02 11.04 11.24 11.20 11.20 11.00 11.11 11.21 11.18 10.47 10.58 10.87 10.83 10.81 10.79 10.65 10.92 10.59 10.91 10.82 10.81 10.84 10.79 10.77 10.87 10.68 10.55 10.58 10.81 10.35 10.91 10.96 10.91 9.80 9.60 9.87 MgO 11.73 11.20 11.11 11.80 11.97 11.43 13.34 12.15 13.79 12.58 12.66 12.31 12.00 12.49 12.20 10.23 10.27 12.15 12.38 12.43 10.19 12.52 12.16 12.12 12.92 12.48 12.26 12.98 12.19 13.10 12.36 12.48 13.41 12.80 13.03 12.72 13.21 14.08 14.02 14.25 13.42 12.95 13.29 12.96 O 2 K 0.90 0.91 0.68 0.55 0.59 0.77 0.82 0.69 0.66 0.61 0.79 0.92 0.59 0.64 0.68 0.81 0.91 0.70 0.65 0.61 1.01 0.93 0.55 0.66 0.70 0.55 0.54 0.77 0.82 0.82 0.90 0.86 0.73 0.81 0.86 1.02 0.95 0.86 0.80 0.85 0.65 0.82 0.87 0.75 0.76 0.72 0.78 Cl 0.04 0.03 0.08 0.09 0.11 0.13 0.04 0.09 0.11 0.12 0.15 0.13 0.12 0.10 0.13 0.06 0.14 0.12 0.11 0.10 0.09 0.08 0.11 0.15 0.17 0.10 0.10 0.04 0.05 0.07 0.08 0.07 0.05 0.05 0.08 0.05 0.05 0.04 0.05 0.09 0.06 0.06 0.06 0.04 0.06 0.02 0.04 O 2 2.03 2.07 1.56 1.47 1.52 1.76 2.43 1.97 1.68 1.62 1.82 2.26 1.68 1.59 1.64 2.42 2.04 1.63 1.63 1.63 2.24 2.28 1.59 1.73 1.69 1.50 1.48 2.39 2.15 2.29 1.85 2.31 2.24 2.18 1.83 2.41 2.37 2.36 2.18 1.99 1.84 1.97 2.01 2.38 2.24 2.28 2.34 Na F 0.36 0.35 0.39 0.36 0.32 0.18 0.23 0.39 0.46 0.31 0.36 0.29 0.35 0.46 0.36 0.38 0.47 0.34 0.42 0.34 0.32 0.40 0.35 0.32 0.41 0.31 0.37 0.21 0.29 0.20 0.34 0.26 0.26 0.25 0.24 0.23 0.31 0.17 0.21 0.24 0.22 0.10 0.11 0.26 0.33 0.26 0.19

Probe 919HE2 919HE3 919HE4 920HAA1 920HAA2 920HAB1 920HAB2 920HAC1 920HAC2 920HAF1 920HAF2 920HB1 920HB2 920HC1 920HC2 920HD1 920HD2 920HH1 920HH2 920HU1 920HU2 920HV1 920HV2 920HW1 920HW2 920HX1 920HX2 921H1 921H2 921HAB1 921HAB2 921HAE1 921HAE2 921HAF1 921HAF2 921HD1 921HD2 921HF1 921HF2 921HG1 921HG2 921HH1 921HH2 921HJ1 921HJ2 921HW1 921HW2 sample no. Unit Tuff of Ryecroft Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Compositions (in Weight Percent) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Nevada.—Continued Range, Nye County, Igneous Rocks in the Southern Toquima Percent) of Amphiboles in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-19 DRS-91-19 DRS-91-19 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 Appendix 5. Appendix 6 89 Amphibole species pargasite pargasite pargasite pargasite pargasite magnesiohastingsite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohornblende magnesiohornblende pargasite pargasite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende edenite magnesiohastingsite pargasite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite edenite K 0.111 0.110 0.116 0.119 0.119 0.118 0.118 0.118 0.114 0.110 0.117 0.153 0.142 0.145 0.140 0.148 0.183 0.179 0.100 0.133 0.187 0.185 0.129 0.126 0.108 0.183 0.102 0.094 0.173 0.174 0.144 0.106 0.105 0.122 0.152 0.147 0.140 0.130 0.127 0.109 0.140 0.191 0.182 0.190 0.187 0.161 Na 0.521 0.509 0.483 0.586 0.587 0.506 0.501 0.281 0.221 0.289 0.296 0.532 0.543 0.308 0.304 0.296 0.275 0.258 0.272 0.229 0.225 0.446 0.177 0.204 0.495 0.500 0.333 0.191 0.225 0.274 0.370 0.459 0.446 0.270 0.277 0.245 0.359 0.228 0.235 0.463 0.499 0.227 0.221 0.459 0.409 0.373 Na 0.128 0.149 0.129 0.145 0.147 0.164 0.167 0.172 0.184 0.202 0.182 0.146 0.130 0.180 0.182 0.193 0.185 0.170 0.174 0.207 0.195 0.139 0.213 0.178 0.141 0.137 0.190 0.221 0.207 0.222 0.174 0.160 0.182 0.195 0.173 0.170 0.149 0.196 0.199 0.156 0.140 0.167 0.178 0.154 0.203 0.191 Ca 1.789 1.793 1.793 1.799 1.790 1.745 1.738 1.704 1.679 1.671 1.677 1.770 1.786 1.693 1.697 1.679 1.681 1.690 1.695 1.685 1.659 1.759 1.664 1.677 1.788 1.783 1.682 1.639 1.647 1.649 1.705 1.730 1.732 1.662 1.694 1.708 1.724 1.672 1.635 1.752 1.774 1.696 1.689 1.766 1.723 1.690 Mn 0.111 0.111 0.118 0.115 0.112 0.114 0.118 0.119 0.053 0.052 0.054 0.032 0.022 0.042 0.041 0.101 0.105 0.124 0.133 0.038 0.044 0.127 0.121 0.126 0.127 0.095 0.103 0.000 0.108 0.040 0.104 0.120 0.008 0.021 0.120 0.123 0.090 0.077 0.070 0.099 0.127 0.130 0.046 0.031 0.027 0.028 2+ Fe 0.029 0.006 0.024 0.023 0.041 0.049 0.055 0.023 0.032 0.004 0.008 0.045 0.040 0.000 0.000 0.001 0.007 0.045 0.029 0.108 0.038 0.062 0.019 0.026 0.063 0.059 0.008 0.022 0.023 0.015 0.031 0.033 0.016 0.044 0.006 0.010 0.013 0.014 0.036 0.046 0.055 0.026 0.014 0.053 0.047 0.008 Mn 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2+ Fe 1.116 1.755 1.795 1.787 1.485 1.374 1.091 1.063 1.610 1.531 1.752 1.732 1.125 1.626 1.633 1.684 1.679 1.693 1.685 1.772 1.714 1.144 1.582 1.522 1.070 1.120 1.716 1.536 1.532 1.708 1.698 1.647 1.708 1.715 1.603 1.391 1.748 1.578 1.673 1.190 1.159 1.526 1.555 1.177 1.149 1.859 Mg 3.119 2.811 2.363 2.378 2.379 2.680 2.806 3.090 3.126 2.751 2.814 2.545 2.597 3.130 2.702 2.718 2.635 2.631 2.593 2.639 2.494 2.533 2.985 2.701 2.987 2.936 2.483 2.723 2.727 2.421 2.478 2.376 2.345 2.418 2.641 2.957 2.497 2.713 2.564 2.931 2.968 2.813 2.750 3.056 3.040 2.291 3+ Fe 0.411 0.289 0.203 0.274 0.194 0.220 0.317 0.333 0.431 0.473 0.441 0.456 0.292 0.294 0.440 0.421 0.443 0.465 0.484 0.456 0.376 0.505 0.353 0.429 0.468 0.248 0.280 0.447 0.485 0.505 0.450 0.421 0.384 0.300 0.496 0.460 0.424 0.441 0.458 0.544 0.321 0.301 0.443 0.461 0.281 0.259 Ti 0.116 0.116 0.110 0.297 0.281 0.256 0.292 0.290 0.294 0.268 0.108 0.085 0.134 0.134 0.320 0.305 0.134 0.144 0.137 0.138 0.129 0.125 0.144 0.138 0.257 0.130 0.342 0.365 0.149 0.179 0.164 0.245 0.260 0.140 0.146 0.142 0.174 0.139 0.123 0.305 0.328 0.139 0.145 0.320 0.353 0.195 Al(vi) 0.111 0.112 0.295 0.342 0.303 0.348 0.310 0.207 0.209 0.100 0.097 0.127 0.081 0.153 0.146 0.097 0.078 0.102 0.087 0.101 0.096 0.214 0.261 0.158 0.083 0.353 0.300 0.206 0.141 0.125 0.242 0.240 0.348 0.387 0.230 0.150 0.086 0.140 0.097 0.253 0.245 0.079 0.089 0.165 0.198 0.243 Al(iv) 1.611 1.725 1.610 1.589 1.707 1.698 1.637 1.592 0.966 0.878 1.057 1.035 1.658 1.648 1.052 1.028 1.038 1.047 1.042 1.018 1.025 1.029 1.618 0.914 0.903 1.812 1.846 1.237 0.933 0.975 1.224 1.337 1.668 1.212 1.134 0.977 1.281 0.998 1.036 1.681 1.742 0.970 1.000 1.582 1.558 1.388 Si 6.411 6.275 6.390 6.293 6.302 6.363 6.408 7.034 7.122 6.943 6.965 6.342 6.352 6.948 6.972 6.962 6.953 6.958 6.982 6.975 6.971 6.382 7.086 7.097 6.188 6.154 6.763 7.067 7.025 6.776 6.663 6.332 6.389 6.788 6.866 7.023 6.719 7.002 6.964 6.319 6.258 7.030 7.000 6.418 6.442 6.612

Probe sample no. 06HF1 06HF2 06HF3 169HAB1 169HAB2 169HE1 169HE2 169HF1 169HF2 169HH1 169HH2 169HQ1 169HQ2 169HS1 169HS2 169HW1 169HW2 197HA1 197HA2 197HA3 197HA4 197HAE1 197HAF1h 197HAF2h 197HB1 197HB2 197HG1 197HG2 197HG2r 197HG3 197HH1 197HH2 197HH2r 197HH3 197HK1 197HK2 197HP1 197HT1 197HV1 197HW1 197HW2 199HAA1 199HAA2 199HAG1 199HAG2 199HAJ1 Unit Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Structural Formulas (in Atoms) and Amphibole Species (Leake and Others, 1997) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) and Amphibole Species (Leake Others, 1997) of Amphiboles in Samples Tertiary

Original sample no. Formulas for amphiboles are given as proportions of oxides (total 16.5 ions) and converted to standard atomic formulas DRS-91-6 DRS-91-6 DRS-91-6 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 Appendix 6. Nevada.—Continued Range, Nye County, [Formulas for amphiboles given as proportions of oxides (total 16.5 ions) and converted end-member proportions] 90 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Amphibole species magnesiohornblende magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite magnesiohornblende edenite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite pargasite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite edenite pargasite magnesiohornblende magnesiohornblende pargasite edenite magnesiohornblende magnesiohastingsite edenite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende K 0.111 0.111 0.112 0.119 0.110 0.116 0.116 0.125 0.176 0.174 0.108 0.121 0.120 0.120 0.120 0.182 0.185 0.145 0.163 0.139 0.140 0.161 0.155 0.150 0.128 0.184 0.176 0.106 0.134 0.130 0.087 0.134 0.170 0.193 0.178 0.182 0.139 0.151 0.146 0.149 0.170 0.127 0.147 0.145 0.125 0.171 0.150 0.128 Na 0.311 0.411 0.264 0.455 0.260 0.241 0.512 0.302 0.320 0.368 0.338 0.368 0.530 0.491 0.307 0.359 0.570 0.585 0.571 0.536 0.663 0.561 0.477 0.170 0.349 0.319 0.244 0.336 0.484 0.498 0.449 0.469 0.567 0.543 0.598 0.363 0.484 0.290 0.269 0.617 0.386 0.323 0.502 0.388 0.266 0.251 0.253 0.278 Na 0.112 0.116 0.114 0.118 0.115 0.117 0.195 0.144 0.154 0.171 0.139 0.108 0.105 0.052 0.072 0.100 0.071 0.104 0.159 0.164 0.106 0.169 0.150 0.191 0.246 0.146 0.154 0.140 0.135 0.138 0.148 0.143 0.120 0.156 0.108 0.171 0.170 0.184 0.196 0.109 0.154 0.164 0.137 0.138 0.166 0.185 0.183 0.165 Ca 1.811 1.711 1.665 1.740 1.696 1.700 1.738 1.683 1.676 1.737 1.724 1.714 1.714 1.804 1.789 1.714 1.725 1.790 1.793 1.800 1.778 1.742 1.755 1.693 1.616 1.734 1.709 1.701 1.746 1.798 1.787 1.757 1.770 1.776 1.745 1.796 1.729 1.768 1.715 1.697 1.807 1.734 1.690 1.754 1.764 1.701 1.690 1.734 Mn 0.117 0.117 0.119 0.115 0.011 0.116 0.112 0.110 0.108 0.099 0.107 0.030 0.128 0.123 0.132 0.136 0.023 0.046 0.106 0.069 0.076 0.006 0.074 0.039 0.022 0.025 0.093 0.107 0.093 0.104 0.028 0.033 0.038 0.030 0.055 0.066 0.054 0.101 0.062 0.101 0.107 0.084 0.124 0.098 0.133 0.103 0.127 0.101 2+ Fe 0.032 0.017 0.032 0.022 0.093 0.092 0.091 0.087 0.085 0.054 0.079 0.069 0.053 0.012 0.005 0.025 0.017 0.082 0.098 0.000 0.050 0.073 0.090 0.045 0.013 0.044 0.043 0.015 0.057 0.042 0.058 0.057 0.049 0.033 0.041 0.000 0.000 0.000 0.000 0.000 0.000 0.021 0.000 0.000 0.000 0.000 0.000 0.000 Mn 0.011 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.016 0.042 0.017 0.015 0.030 0.000 0.008 0.020 0.008 0.016 0.000 0.010 2+ Fe 1.411 1.611 1.630 1.950 1.595 1.571 1.021 1.676 1.658 1.693 1.591 1.622 1.675 1.033 1.012 1.744 1.876 1.675 1.725 0.863 0.857 1.682 1.079 0.997 1.602 1.796 1.693 1.584 1.735 1.142 1.176 1.093 1.150 1.610 1.612 1.787 1.980 1.695 1.668 2.016 1.758 1.599 1.910 1.755 1.592 1.678 1.604 1.443 Mg 3.117 2.626 2.172 2.797 2.784 2.970 2.727 2.783 2.800 2.876 2.783 2.778 3.122 2.491 2.383 2.498 2.436 3.142 3.158 2.429 2.694 3.036 3.022 2.621 2.468 2.542 2.838 2.516 3.044 2.992 3.066 3.026 2.580 2.537 2.593 2.475 2.209 2.615 2.637 2.066 2.528 2.631 2.259 2.478 2.732 2.627 2.679 2.903 3+ Fe 0.411 0.486 0.404 0.415 0.441 0.539 0.409 0.366 0.330 0.373 0.407 0.365 0.368 0.453 0.440 0.387 0.328 0.324 0.489 0.439 0.261 0.312 0.330 0.400 0.478 0.417 0.499 0.489 0.296 0.262 0.333 0.305 0.363 0.344 0.386 0.351 0.216 0.353 0.373 0.293 0.391 0.522 0.382 0.342 0.462 0.360 0.439 0.353 Ti 0.118 0.129 0.238 0.120 0.126 0.287 0.130 0.136 0.148 0.120 0.134 0.144 0.296 0.261 0.152 0.177 0.271 0.268 0.331 0.331 0.265 0.305 0.328 0.343 0.105 0.151 0.137 0.095 0.156 0.307 0.368 0.303 0.312 0.284 0.284 0.267 0.174 0.275 0.148 0.147 0.265 0.166 0.150 0.223 0.166 0.145 0.149 0.154 Al(vi) 0.130 0.235 0.073 0.078 0.182 0.059 0.057 0.028 0.039 0.054 0.038 0.182 0.157 0.172 0.177 0.227 0.247 0.175 0.214 0.363 0.277 0.226 0.237 0.195 0.169 0.129 0.073 0.104 0.212 0.201 0.205 0.207 0.164 0.225 0.142 0.198 0.278 0.171 0.160 0.329 0.146 0.097 0.217 0.239 0.088 0.173 0.128 0.137 Al(iv) 1.067 1.604 0.945 0.952 1.841 1.029 1.021 1.092 1.038 1.060 1.107 1.749 1.694 1.208 1.277 1.691 1.719 1.952 1.888 1.852 1.720 1.724 1.719 0.913 1.223 1.197 0.864 1.240 1.658 1.752 1.623 1.643 1.681 1.674 1.697 1.238 1.529 1.054 1.019 1.808 1.246 1.204 1.583 1.314 0.996 1.017 1.050 1.027 Si 6.112 6.933 6.396 7.055 7.048 6.159 6.971 6.979 6.908 6.962 6.940 6.893 6.251 6.306 6.792 6.723 6.309 6.281 6.048 6.148 6.280 6.276 6.281 7.087 6.777 6.803 7.136 6.760 6.342 6.248 6.377 6.357 6.319 6.326 6.303 6.762 6.471 6.946 6.981 6.192 6.754 6.796 6.417 6.686 7.004 6.983 6.950 6.973

Probe 199HAJ2 199HAJ3 199HAK1 199HAK2 199HD1 199HG1 199HG2 199HJ1 199HJ2 199HK1 199HK2 199HS1 199HS2 199HT1 199HT2 203HAC1 203HAC2 203HAD1 203HAD2 203HAE1 203HAE2 203HD1 203HD2 203HS1 203HS1 203HS2 203HS2 203HS3r 203HT1 203HT1 203HT2 203HT3 203HV1 203HV1 203HV2 204HAA1 204HAA2 204HAD1 204HAE1 204HE1 204HK1 204HK2 204HL1 204HL2 204HR1 204HT1 204HT2 204HV1 sample no. Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Structural Formulas (in Atoms) and Amphibole Species (Leake and Others, 1997) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) and Amphibole Species (Leake Others, 1997) of Amphiboles in Samples Tertiary

Original sample no. DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 Appendix 6. Nevada.—Continued Range, Nye County, [Formulas for amphiboles given as proportions of oxides (total 16.5 ions) and converted end-member proportions] Appendix 6 91 Amphibole species magnesiohornblende magnesiohornblende pargasite pargasite pargasite magnesiohastingsite magnesiohornblende pargasite pargasite magnesiohastingsite pargasite pargasite pargasite pargasite pargasite magnesiohornblende magnesiohornblende pargasite edenite magnesiohastingsite magnesiohastingsite pargasite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohastingsite pargasite magnesiohastingsite magnesiohastingsite edenite edenite edenite pargasite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite edenite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite ferrohornblende magnesiohornblende magnesiohornblende magnesiohornblende edenite K 0.113 0.110 0.112 0.113 0.118 0.129 0.136 0.184 0.178 0.180 0.150 0.149 0.154 0.153 0.156 0.154 0.147 0.189 0.129 0.139 0.162 0.171 0.191 0.163 0.157 0.212 0.179 0.256 0.132 0.134 0.182 0.165 0.134 0.107 0.106 0.103 0.177 0.184 0.152 0.156 0.155 0.149 0.175 0.129 0.167 0.150 0.142 0.168 Na 0.310 0.299 0.525 0.493 0.509 0.524 0.326 0.562 0.556 0.587 0.554 0.503 0.529 0.539 0.563 0.300 0.352 0.546 0.397 0.575 0.585 0.546 0.460 0.177 0.237 0.454 0.436 0.457 0.446 0.393 0.391 0.402 0.452 0.283 0.273 0.278 0.499 0.437 0.512 0.498 0.577 0.519 0.495 0.320 0.314 0.287 0.335 0.464 Na 0.117 0.119 0.117 0.110 0.155 0.159 0.124 0.146 0.162 0.150 0.127 0.161 0.152 0.187 0.169 0.143 0.136 0.188 0.170 0.163 0.140 0.136 0.108 0.153 0.132 0.228 0.208 0.162 0.174 0.148 0.151 0.121 0.152 0.157 0.169 0.196 0.186 0.142 0.172 0.173 0.186 0.163 0.186 0.175 0.227 0.133 0.139 0.102 Ca 1.748 1.739 1.807 1.760 1.793 1.749 1.753 1.763 1.776 1.765 1.780 1.781 1.785 1.806 1.806 1.735 1.762 1.805 1.781 1.787 1.797 1.794 1.756 1.624 1.656 1.721 1.753 1.721 1.722 1.789 1.781 1.750 1.767 1.707 1.686 1.696 1.757 1.739 1.694 1.699 1.747 1.715 1.737 1.608 1.749 1.738 1.810 1.833 Mn 0.097 0.102 0.067 0.084 0.089 0.049 0.092 0.015 0.017 0.074 0.068 0.030 0.033 0.051 0.059 0.041 0.038 0.032 0.078 0.077 0.095 0.053 0.092 0.120 0.108 0.098 0.049 0.018 0.010 0.084 0.073 0.060 0.051 0.094 0.098 0.099 0.047 0.057 0.038 0.032 0.017 0.018 0.023 0.127 0.063 0.056 0.088 0.057 2+ Fe 0.113 0.117 0.011 0.000 0.000 0.002 0.010 0.001 0.040 0.006 0.095 0.088 0.000 0.000 0.001 0.013 0.000 0.000 0.036 0.031 0.000 0.000 0.000 0.000 0.000 0.020 0.027 0.029 0.019 0.023 0.025 0.037 0.025 0.030 0.019 0.019 0.054 0.032 0.096 0.083 0.073 0.081 0.064 0.038 0.055 0.067 0.000 0.000 Mn 0.019 0.015 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.044 0.058 0.000 0.000 0.031 0.049 0.000 0.000 0.050 0.023 0.030 0.004 0.029 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.018 0.002 2+ Fe 1.115 1.589 1.564 1.431 1.915 1.923 1.414 1.462 0.721 0.965 1.731 1.753 1.388 1.419 1.425 1.468 1.451 1.544 1.747 1.702 1.909 1.895 1.729 1.989 1.629 1.595 1.949 1.846 0.846 0.798 1.852 1.738 1.356 1.392 1.581 1.594 1.583 1.098 1.212 1.050 1.101 1.249 1.285 2.189 1.786 1.666 1.473 1.419 Mg 2.611 2.767 2.791 2.751 2.198 2.214 2.686 2.849 3.284 3.020 2.393 2.385 2.821 2.789 2.723 2.656 2.819 2.734 2.395 2.567 2.245 2.238 2.387 2.168 2.659 2.131 2.327 3.062 3.164 2.405 2.494 2.790 2.741 2.765 2.765 2.786 3.099 3.007 2.972 2.930 2.799 2.867 2.948 2.126 2.462 2.577 2.893 2.897 3+ Fe 0.111 0.112 0.511 0.338 0.355 0.242 0.328 0.313 0.310 0.341 0.381 0.381 0.259 0.238 0.164 0.179 0.205 0.270 0.240 0.274 0.269 0.358 0.185 0.390 0.472 0.408 0.254 0.519 0.441 0.331 0.341 0.341 0.265 0.432 0.407 0.410 0.353 0.309 0.463 0.399 0.315 0.345 0.305 0.436 0.429 0.484 0.308 0.201 Ti 0.112 0.165 0.167 0.276 0.224 0.236 0.296 0.170 0.225 0.215 0.341 0.324 0.412 0.396 0.433 0.320 0.212 0.231 0.353 0.231 0.299 0.298 0.357 0.231 0.120 0.151 0.256 0.258 0.255 0.236 0.185 0.180 0.199 0.246 0.109 0.107 0.262 0.260 0.231 0.247 0.374 0.394 0.338 0.171 0.169 0.133 0.173 0.282 Al(vi) 0.110 0.114 0.122 0.108 0.301 0.334 0.314 0.294 0.179 0.389 0.418 0.232 0.241 0.268 0.232 0.209 0.302 0.248 0.252 0.343 0.204 0.248 0.207 0.313 0.222 0.129 0.122 0.255 0.314 0.318 0.361 0.228 0.246 0.314 0.356 0.124 0.188 0.212 0.283 0.324 0.263 0.279 0.123 0.077 0.154 0.139 0.135 0.199 Al(iv) 1.074 1.072 1.679 1.636 1.671 1.709 1.184 1.768 1.778 1.753 1.682 1.676 1.702 1.796 1.764 1.184 1.274 1.706 1.366 1.746 1.802 1.762 1.614 0.941 1.038 1.647 1.604 1.787 1.702 1.388 1.384 1.420 1.542 0.987 0.932 0.933 1.598 1.490 1.700 1.685 1.896 1.894 1.600 1.078 1.268 1.188 1.164 1.487 Si 6.926 6.928 6.321 6.364 6.329 6.291 6.816 6.232 6.222 6.247 6.318 6.324 6.298 6.204 6.236 6.816 6.726 6.294 6.634 6.254 6.198 6.238 6.386 7.059 6.962 6.353 6.396 6.213 6.298 6.612 6.616 6.580 6.458 7.013 7.068 7.067 6.402 6.510 6.300 6.315 6.104 6.106 6.400 6.922 6.732 6.812 6.836 6.513

Probe 204HV2 204HW1 204HW2 204HZ1 204HZ2 21HJ1 21HJ2 21HK1 21HK2 21HL1 21HL2 21HN1 21HN2 24HB1 24HB2 24HJ1 24HJ2 24HQ1 24HQ2 24HS1 24HS2 24HT1 34HA1 34HA2 34HB1 34HB2 34HC1 34HD1 34HD2 34HE1 34HE2 34HP1 34HP2 44HG1 44HG2 44HH1 44HJ1 44HJ2 52HA1 52HA2 52HK1 52HK2 52HP1 913HF1 919HC1 919HC2 919HE1 919HE2 sample no. Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, Tuff Bates Mountain Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Structural Formulas (in Atoms) and Amphibole Species (Leake and Others, 1997) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) and Amphibole Species (Leake Others, 1997) of Amphiboles in Samples Tertiary

Original sample no. DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-85-204 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-91-3 DRS-91-19 DRS-91-19 DRS-91-19 DRS-91-19 Appendix 6. Nevada.—Continued Range, Nye County, [Formulas for amphiboles given as proportions of oxides (total 16.5 ions) and converted end-member proportions] 92 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada Amphibole species pargasite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite edenite magnesiohornblende magnesiohornblende edenite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende pargasite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohastingsite magnesiohastingsite magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende magnesiohornblende pargasite edenite magnesiohastingsite edenite magnesiohastingsite magnesiohastingsite magnesiohastingsite edenite pargasite magnesiohastingsite magnesiohastingsite magnesiohastingsite edenite magnesiohornblende edenite edenite magnesiohastingsite magnesiohastingsite magnesiohastingsite magnesiohastingsite K 0.111 0.114 0.114 0.119 0.171 0.126 0.102 0.109 0.145 0.157 0.129 0.124 0.148 0.177 0.121 0.128 0.153 0.174 0.131 0.123 0.192 0.178 0.103 0.124 0.131 0.102 0.101 0.144 0.152 0.154 0.170 0.162 0.136 0.150 0.159 0.191 0.178 0.163 0.150 0.159 0.151 0.161 0.139 0.142 0.134 0.145 Na 0.311 0.488 0.316 0.248 0.266 0.344 0.519 0.396 0.308 0.270 0.375 0.535 0.299 0.318 0.312 0.595 0.448 0.307 0.284 0.524 0.505 0.270 0.289 0.286 0.282 0.182 0.548 0.452 0.522 0.398 0.555 0.535 0.495 0.394 0.484 0.496 0.556 0.471 0.415 0.338 0.377 0.366 0.501 0.457 0.508 0.526 Na 0.102 0.125 0.169 0.164 0.158 0.182 0.166 0.169 0.189 0.146 0.122 0.183 0.135 0.157 0.103 0.142 0.158 0.156 0.179 0.125 0.155 0.181 0.203 0.195 0.146 0.238 0.128 0.156 0.133 0.132 0.106 0.105 0.124 0.124 0.202 0.178 0.123 0.147 0.148 0.177 0.178 0.197 0.172 0.180 0.138 0.141 Ca 1.850 1.797 1.640 1.656 1.716 1.729 1.706 1.697 1.669 1.725 1.777 1.682 1.722 1.712 1.820 1.732 1.710 1.702 1.686 1.765 1.742 1.676 1.661 1.661 1.700 1.631 1.779 1.748 1.759 1.768 1.806 1.802 1.766 1.766 1.735 1.736 1.787 1.756 1.752 1.686 1.703 1.703 1.734 1.713 1.757 1.757 Mn 0.114 0.118 0.118 0.115 0.112 0.116 0.117 0.048 0.069 0.128 0.134 0.090 0.122 0.124 0.121 0.101 0.124 0.130 0.077 0.120 0.122 0.127 0.107 0.098 0.131 0.131 0.044 0.056 0.056 0.054 0.044 0.054 0.057 0.051 0.026 0.034 0.047 0.049 0.050 0.054 0.029 0.023 0.027 0.039 0.027 0.025 2+ Fe 0.011 0.011 0.000 0.008 0.063 0.045 0.000 0.006 0.010 0.021 0.000 0.012 0.025 0.000 0.000 0.006 0.010 0.014 0.021 0.003 0.005 0.032 0.006 0.013 0.038 0.014 0.049 0.040 0.052 0.046 0.045 0.038 0.052 0.059 0.036 0.053 0.044 0.048 0.050 0.083 0.090 0.077 0.067 0.068 0.078 0.078 Mn 0.022 0.000 0.000 0.000 0.000 0.005 0.000 0.000 0.000 0.000 0.013 0.000 0.000 0.000 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2+ Fe 1.611 1.811 1.612 1.381 1.639 1.684 1.933 1.762 1.615 1.651 2.013 1.658 1.645 1.625 1.885 1.862 1.641 1.616 1.586 1.952 1.841 1.526 1.610 1.605 1.582 1.520 1.417 1.377 1.462 1.381 1.485 1.345 1.413 1.305 1.362 1.253 1.595 1.390 1.358 1.147 1.089 1.100 1.197 1.286 1.193 1.279 Mg 2.711 2.659 2.991 2.742 2.758 2.578 2.178 2.461 2.694 2.616 2.441 2.151 2.607 2.743 2.687 2.273 2.288 2.666 2.718 2.705 2.197 2.273 2.734 2.663 2.648 2.828 2.738 2.670 2.824 2.687 2.884 2.633 2.721 2.917 2.806 2.850 2.528 2.774 2.877 3.028 3.030 3.069 2.914 2.830 2.899 2.833 3+ Fe 0.170 0.271 0.421 0.434 0.436 0.313 0.445 0.465 0.492 0.451 0.351 0.471 0.405 0.451 0.268 0.515 0.459 0.450 0.471 0.412 0.358 0.497 0.473 0.497 0.393 0.452 0.324 0.333 0.375 0.349 0.309 0.399 0.397 0.445 0.219 0.302 0.317 0.338 0.349 0.476 0.416 0.350 0.329 0.373 0.363 0.356 Ti 0.316 0.176 0.124 0.120 0.178 0.323 0.184 0.141 0.136 0.170 0.264 0.137 0.135 0.134 0.272 0.189 0.140 0.137 0.146 0.245 0.262 0.141 0.150 0.145 0.127 0.123 0.246 0.218 0.267 0.212 0.292 0.247 0.272 0.196 0.366 0.352 0.291 0.222 0.219 0.177 0.247 0.274 0.281 0.218 0.293 0.278 Al(vi) 0.220 0.181 0.075 0.077 0.124 0.249 0.149 0.085 0.104 0.128 0.208 0.127 0.072 0.102 0.294 0.146 0.094 0.080 0.092 0.194 0.266 0.103 0.104 0.104 0.070 0.166 0.342 0.248 0.209 0.174 0.280 0.299 0.196 0.137 0.247 0.243 0.269 0.276 0.197 0.172 0.218 0.207 0.279 0.293 0.252 0.253 Al(iv) 1.113 1.114 1.580 1.121 0.924 0.962 1.246 1.702 1.321 1.095 1.065 1.295 1.677 1.100 1.051 1.105 1.749 1.519 1.082 1.075 1.686 1.677 1.073 1.087 0.956 0.910 1.723 1.465 1.661 1.382 1.786 1.757 1.659 1.403 1.670 1.745 1.765 1.531 1.410 1.283 1.479 1.435 1.638 1.521 1.705 1.696 Si 6.420 6.879 7.076 7.038 6.754 6.298 6.679 6.905 6.935 6.705 6.323 6.900 6.949 6.895 6.251 6.481 6.887 6.918 6.925 6.314 6.323 6.927 6.913 6.886 7.044 7.090 6.277 6.535 6.339 6.618 6.214 6.243 6.341 6.597 6.330 6.255 6.235 6.469 6.590 6.717 6.521 6.565 6.362 6.479 6.295 6.304

Probe 919HE3 919HE4 920HAA1 920HAA2 920HAB1 920HAB2 920HAC1 920HAC2 920HAF1 920HAF2 920HB1 920HB2 920HC1 920HC2 920HD1 920HD2 920HH1 920HH2 920HU1 920HU2 920HV1 920HV2 920HW1 920HW2 920HX1 920HX2 921H1 921H2 921HAB1 921HAB2 921HAE1 921HAE2 921HAF1 921HAF2 921HD1 921HD2 921HF1 921HF2 921HG1 921HG2 921HH1 921HH2 921HJ1 921HJ2 921HW1 921HW2 sample no. Unit Structural Formulas (in Atoms) and Amphibole Species (Leake and Others, 1997) of Amphiboles in Samples of Tertiary Igneous Rocks in the Southern Toquima Igneous Rocks in the Southern Toquima Structural Formulas (in Atoms) and Amphibole Species (Leake Others, 1997) of Amphiboles in Samples Tertiary Tuff of Ryecroft Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson

Original sample no. DRS-91-19 DRS-91-19 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 Appendix 6. Nevada.—Continued Range, Nye County, [Formulas for amphiboles given as proportions of oxides (total 16.5 ions) and converted end-member proportions] Appendix 7 93 FS 0.1411 0.1361 0.1358 0.1329 0.1341 0.1398 0.1384 0.1305 0.1379 0.1350 0.1402 0.1366 0.1375 0.1296 0.1350 0.1374 0.1362 0.1364 0.1347 0.1394 0.1407 0.1388 0.1431 0.1448 0.1371 0.1390 0.1435 0.1406 0.1383 0.1465 0.1430 0.1481 0.1449 0.1366 0.1393 0.1410 0.1426 0.1401 0.1434 0.1402 0.1339 0.1333 0.1329 0.1389 0.1374 0.1398 0.1316 0.1343 EN 0.4111 0.4112 0.4115 0.4041 0.4018 0.4102 0.4062 0.4061 0.4047 0.3956 0.4014 0.3986 0.4028 0.4025 0.4106 0.4045 0.4028 0.4052 0.3952 0.4004 0.4014 0.4028 0.3992 0.3936 0.4185 0.4169 0.3991 0.3953 0.4043 0.4043 0.3974 0.3995 0.3929 0.3965 0.4088 0.4145 0.4027 0.4052 0.4066 0.4090 0.4016 0.4027 0.4046 0.4109 0.4149 0.4125 0.4148 0.4239 WO 0.4599 0.4624 0.4569 0.4596 0.4541 0.4569 0.4584 0.4665 0.4637 0.4612 0.4606 0.4600 0.4598 0.4605 0.4597 0.4586 0.4684 0.4649 0.4593 0.4565 0.4620 0.4632 0.4367 0.4460 0.4620 0.4612 0.4550 0.4574 0.4561 0.4575 0.4590 0.4586 0.4546 0.4462 0.4562 0.4537 0.4508 0.4509 0.4550 0.4572 0.4614 0.4559 0.4522 0.4486 0.4478 0.4487 0.4444 0.4546 Total Total 99.60 99.34 99.20 99.06 99.75 99.47 98.72 99.41 99.24 99.60 99.20 99.46 99.10 99.41 98.60 98.91 98.43 98.24 98.27 98.38 99.43 98.36 98.80 99.79 99.64 99.92 99.44 99.82 99.38 99.83 99.92 99.37 99.60 99.75 98.99 98.95 98.40 99.19 99.58 99.87 99.60 99.48 100.14 100.09 100.03 100.05 100.63 100.04 FeO 8.33 8.29 8.16 8.19 8.53 8.43 8.00 8.41 8.22 8.57 8.37 8.42 7.94 8.25 8.35 8.33 8.30 8.19 8.40 8.61 8.53 8.73 8.90 8.46 8.67 8.79 8.74 8.62 9.05 8.75 9.03 8.81 8.41 8.61 8.68 8.78 8.82 8.63 8.76 8.55 8.16 8.14 8.18 8.55 8.44 8.62 8.17 8.24 1.11 0.88 0.86 0.84 0.80 0.92 0.97 0.75 0.82 0.91 0.97 0.88 0.80 0.83 0.90 0.84 0.98 0.93 0.90 0.90 0.99 0.97 0.78 0.78 1.00 0.88 0.95 0.85 1.04 0.88 0.97 0.99 0.84 0.88 0.79 0.80 0.83 0.94 0.91 0.88 0.90 0.87 0.87 0.75 0.73 0.70 0.78 0.87 MnO 2 SiO 52.67 52.52 52.30 52.35 52.40 52.56 51.90 52.64 52.66 52.54 52.47 52.51 52.42 52.62 52.17 52.20 52.28 52.31 52.13 51.60 52.89 51.82 51.91 53.01 52.87 52.40 52.65 52.94 52.87 52.47 52.65 52.57 52.94 53.19 52.24 52.69 52.68 52.97 52.03 52.40 52.24 53.06 53.15 52.79 52.66 53.52 53.02 53.00 3 O 2 1.20 1.21 1.25 1.22 1.59 1.23 1.29 0.90 1.10 1.22 0.97 1.13 1.18 1.20 1.09 1.14 0.71 0.75 1.08 1.23 0.67 0.88 1.39 1.15 0.70 1.41 0.87 0.87 0.83 1.24 1.28 1.06 1.21 0.88 1.29 1.08 1.00 0.97 1.27 1.16 0.85 0.87 0.90 1.37 1.43 1.43 1.26 1.01 Al 2 TiO 0.11 0.11 0.11 0.11 0.22 0.17 0.21 0.21 0.27 0.20 0.23 0.13 0.15 0.17 0.10 0.19 0.20 0.20 0.17 0.16 0.06 0.05 0.19 0.06 0.03 0.07 0.08 0.13 0.13 0.08 0.17 0.19 0.25 0.15 0.15 0.18 0.13 0.13 0.07 0.19 0.09 0.10 0.10 0.18 0.16 0.19 0.10 0.12 CaO 21.97 22.05 21.89 21.90 21.61 21.72 21.94 22.20 22.05 22.00 22.03 21.99 21.98 21.97 21.81 21.91 22.24 22.06 21.61 21.81 22.16 22.06 20.94 21.49 22.50 22.05 22.08 22.25 21.98 21.85 21.84 21.77 21.84 21.53 21.91 22.05 21.75 21.68 21.70 21.76 21.95 21.72 21.74 21.57 21.47 21.59 21.53 21.75 MgO 14.11 13.87 13.77 14.13 13.91 13.90 13.83 14.15 13.53 13.72 13.67 13.85 13.83 13.87 13.74 13.91 13.48 13.66 13.58 13.83 13.76 13.47 14.43 14.44 13.97 13.59 14.10 14.14 13.77 13.72 13.44 13.53 14.12 14.38 13.90 14.15 14.10 14.14 13.76 13.78 13.84 14.07 14.33 14.25 14.29 14.23 14.77 14.14 O 2 K 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cl 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 0.45 0.45 0.43 0.49 0.51 0.50 0.46 0.49 0.49 0.51 0.43 0.47 0.47 0.47 0.39 0.42 0.39 0.29 0.39 0.34 0.40 0.31 0.38 0.38 0.30 0.39 0.40 0.36 0.37 0.37 0.44 0.42 0.32 0.31 0.38 0.37 0.29 0.35 0.36 0.35 0.34 0.35 0.29 0.41 0.41 0.35 0.42 0.35 Na F 0.01 0.01 0.00 0.00 0.00 0.03 0.00 0.00 0.03 0.02 0.02 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Probe sample no. 169CAA1 169CAA2 169CAD1 169CAD2 169CD1 169CD2 169CM1 169CM2 169CR1 169CR2 169CU1 169CU2 169CY1 169CY2 197CAC1 197CAC2 197CS1 197CS2 197CU1 197CU2 197CX1 197CX2 199CAC1 199CAC2 199CAC3 199CAD1 199CAD2 199CAD3 199CM1 199CM2 199CN1 199CN2 199CP1 199CP2 199CU1 199CU2 199CW1 199CW2 203CG1 203CG2 203CK1 203CK2 203CK3 203CL1 203CL2 203CM1 203CN1 203CR1 Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Compositions (in Weight Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Range, Nye County, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Compositions (in Weight

Original sample no. DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-91-169 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-197 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-199 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 Appendix 7. Nevada.—Continued 94 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada FS 0.3119 0.3110 0.1362 0.1429 0.1380 0.1365 0.1421 0.3533 0.3483 0.1912 0.1863 0.1687 0.1483 0.1679 0.1685 0.2675 0.2758 0.3213 0.2900 0.3229 0.3155 0.3161 0.3190 0.1791 0.1876 0.1736 0.1866 0.1377 0.1407 0.1429 0.1391 0.1398 0.4465 0.4675 0.4698 0.4627 0.4280 0.4722 0.4836 0.4276 0.4709 0.4699 0.4755 0.4501 0.4706 0.4133 0.4169 0.4833 EN 0.4118 0.4090 0.3921 0.3988 0.4020 0.3888 0.6101 0.6145 0.4082 0.4090 0.4156 0.4326 0.4190 0.4144 0.7022 0.6904 0.6436 0.6749 0.6568 0.6452 0.6566 0.6533 0.6489 0.6487 0.4140 0.4251 0.4020 0.3994 0.3954 0.3925 0.4007 0.4008 0.5212 0.5009 0.4981 0.5060 0.5260 0.4967 0.4826 0.5400 0.4967 0.4985 0.4933 0.5185 0.4962 0.5539 0.5497 0.4854 WO 0.4114 0.0311 0.4548 0.4650 0.4632 0.4615 0.4691 0.0367 0.0372 0.4006 0.4047 0.4158 0.4192 0.4131 0.4170 0.0304 0.0338 0.0351 0.0350 0.0312 0.0319 0.0324 0.0312 0.0351 0.0323 0.4069 0.4006 0.4013 0.4629 0.4639 0.4646 0.4601 0.4594 0.0323 0.0316 0.0321 0.0313 0.0461 0.0338 0.0324 0.0324 0.0316 0.0312 0.0314 0.0332 0.0327 0.0334 0.0313 Total Total 99.85 99.23 99.45 99.20 99.04 99.06 99.04 98.96 99.57 99.97 99.67 99.96 99.97 99.60 99.43 98.87 99.31 98.84 98.75 98.23 98.55 98.71 98.70 98.77 98.24 99.18 98.15 98.08 97.79 98.99 98.18 98.51 99.20 98.49 98.51 98.10 97.91 98.71 98.43 98.32 100.06 100.38 100.04 100.34 100.32 100.00 100.12 100.04 8.46 8.83 8.53 8.46 8.77 9.11 8.24 8.45 8.53 8.39 8.41 FeO 11.64 11.24 11.43 11.27 21.86 21.76 10.33 10.25 10.39 17.28 17.61 20.25 18.39 19.77 20.53 19.85 19.91 19.79 19.86 10.85 10.61 26.68 28.04 27.93 27.54 25.91 28.07 28.54 25.72 28.24 27.96 28.09 27.00 27.99 25.01 25.10 28.66 0.89 0.93 0.88 0.94 1.07 0.47 0.52 0.34 0.31 0.31 0.24 0.28 0.34 0.39 0.40 0.42 0.46 0.45 0.48 0.51 0.52 0.43 0.51 0.28 0.34 0.37 0.34 0.91 0.86 0.90 0.96 0.85 0.86 0.94 0.94 0.90 0.87 0.95 0.96 0.81 0.96 0.94 0.97 0.90 0.93 0.94 0.89 1.06 MnO 2 SiO 52.49 52.34 52.25 52.47 52.57 52.39 52.21 50.90 50.73 51.35 51.33 51.69 51.45 54.34 53.76 52.82 53.55 53.22 53.08 53.15 53.49 53.07 53.20 51.41 51.63 52.07 51.74 52.39 52.20 52.58 52.43 52.35 50.54 51.12 50.36 50.60 50.03 51.07 50.17 51.39 51.04 50.73 50.94 50.38 50.26 51.37 51.41 50.32 3 O 2 1.11 1.37 1.53 1.38 1.23 1.17 1.18 1.24 2.33 2.72 1.99 2.40 1.85 2.07 1.06 1.36 1.34 1.45 1.30 1.16 1.01 1.09 1.40 1.24 2.13 1.83 1.41 1.58 1.29 1.24 1.03 1.38 0.83 0.46 0.63 0.43 0.67 0.61 0.73 0.63 0.50 0.52 0.48 0.62 0.46 0.75 0.66 0.46 Al 2 TiO 0.19 0.25 0.19 0.18 0.18 0.32 0.33 0.64 0.73 0.60 0.63 0.55 0.62 0.25 0.36 0.34 0.35 0.30 0.27 0.28 0.30 0.36 0.33 0.60 0.63 0.34 0.48 0.15 0.19 0.16 0.17 0.20 0.29 0.25 0.17 0.21 0.19 0.25 0.21 0.18 0.19 0.19 0.20 0.24 0.17 0.25 0.23 0.18 1.77 1.81 1.53 1.69 1.73 1.73 1.55 1.58 1.61 1.54 1.71 1.57 1.51 1.48 1.49 1.45 2.18 1.44 1.56 1.52 1.52 1.47 1.44 1.47 1.54 1.55 1.57 1.45 CaO 22.05 22.42 22.34 22.32 22.60 19.04 19.06 19.88 20.10 19.68 20.07 19.23 19.06 19.15 19.40 21.61 21.75 21.65 21.66 21.56 MgO 14.25 13.59 13.82 13.98 13.46 21.18 21.54 13.95 13.85 14.28 14.91 14.35 14.34 25.44 24.73 22.76 24.00 23.36 23.01 23.51 23.13 22.79 22.66 14.06 14.08 14.58 13.62 13.40 13.32 13.14 13.56 13.52 17.47 16.86 16.61 16.90 17.86 16.57 15.98 18.22 16.72 16.64 16.35 17.45 16.56 18.80 18.56 16.15 O 2 K 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 Cl 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.01 0.01 0.01 0.00 0.00 0.01 0.01 0.02 0.00 0.00 0.01 0.01 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 O 2 0.37 0.50 0.46 0.47 0.51 0.01 0.04 0.37 0.37 0.31 0.28 0.30 0.28 0.02 0.03 0.01 0.05 0.02 0.02 0.04 0.05 0.04 0.04 0.32 0.32 0.28 0.29 0.42 0.49 0.51 0.48 0.49 0.05 0.02 0.03 0.04 0.03 0.02 0.03 0.05 0.04 0.04 0.03 0.03 0.00 0.04 0.01 0.04 Na F 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00

Probe sample no. 203CU1 203CU1 203CW1 203CX1 203CZ1 34CF1 34CF2 34CG1 34CG2 34CH1 34CH2 34CI1 34CI2 34CJ1 34CJ2 34CK1 34CK2 34CL1 34CL2 34CM1 34CM2 34CR1 34CR2 34CS1 34CS2 34CT1 34CT2 44CK1 44CK2 44CL1 44CM1 44CM2 52CB1 52CD1 52CD2 52CE2 52CF1 52CF2 52CG1 52CH1 52CH2 52CJ1 52CJ2 52CL1 52CL2 59CA1 59CA2 59CC1 Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, Isom-type tuff Isom-type tuff Isom-type tuff Compositions (in Weight Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Range, Nye County, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Compositions (in Weight

Original sample no. DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-85-203 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-59 DRS-87-59 DRS-87-59 Appendix 7. Nevada.—Continued Appendix 7 95 FS 0.4711 0.4884 0.2712 0.4649 0.4661 0.3700 0.3821 0.4744 0.4654 0.4690 0.4273 0.4676 0.4927 0.4922 0.4891 0.4857 0.1387 0.1431 0.1367 0.1524 0.1408 0.1352 0.1588 0.1558 0.1518 0.1521 0.1581 0.1540 0.1528 0.1563 EN 0.4802 0.6958 0.5017 0.5020 0.5932 0.5790 0.4951 0.4934 0.5012 0.4996 0.5377 0.5010 0.4724 0.4758 0.4785 0.4821 0.4083 0.4030 0.4032 0.3816 0.3953 0.4049 0.4010 0.4042 0.4050 0.4031 0.4020 0.4002 0.4080 0.4046 WO 0.0314 0.0330 0.0335 0.0319 0.0368 0.0389 0.0338 0.0323 0.0334 0.0314 0.0351 0.0314 0.0348 0.0320 0.0324 0.0322 0.4530 0.4539 0.4601 0.4660 0.4638 0.4599 0.4402 0.4400 0.4432 0.4448 0.4399 0.4458 0.4392 0.4391 Total Total 98.38 97.60 98.45 98.32 98.78 98.23 98.55 98.51 97.72 97.79 98.41 98.29 97.50 97.58 97.99 98.08 99.94 99.83 99.84 99.86 100.48 100.38 100.78 100.54 100.21 100.57 100.59 100.38 100.43 100.28 8.61 8.82 8.51 9.33 8.67 8.40 9.67 9.37 9.40 9.82 9.56 9.46 9.56 FeO 28.96 16.99 27.83 27.72 22.83 23.32 28.10 28.34 27.64 27.88 25.81 28.00 29.10 29.15 29.14 28.94 10.02 1.11 1.06 0.38 0.99 1.01 0.56 0.54 1.01 1.04 1.04 1.02 0.89 1.12 1.12 1.10 1.09 0.95 0.88 0.88 1.04 0.99 0.89 0.55 0.71 0.65 0.65 0.53 0.69 0.62 0.71 MnO 2 SiO 50.28 52.29 50.46 50.63 51.53 51.27 50.50 50.53 50.19 50.08 51.17 50.23 49.34 49.44 49.56 49.80 53.07 52.44 52.59 52.63 52.69 52.94 52.43 52.21 53.36 53.34 51.87 52.52 53.36 53.23 3 O 2 0.44 1.49 0.52 0.49 1.05 1.03 0.50 0.37 0.43 0.47 0.49 0.46 0.44 0.38 0.45 0.43 1.10 1.69 1.51 1.30 1.16 1.25 1.07 1.29 1.02 1.01 1.55 0.91 0.89 1.00 Al 2 TiO 0.19 0.34 0.22 0.21 0.44 0.35 0.28 0.16 0.16 0.19 0.16 0.17 0.22 0.19 0.20 0.18 0.15 0.25 0.31 0.24 0.16 0.17 0.24 0.19 0.15 0.13 0.23 0.12 0.17 0.10 1.46 1.61 1.57 1.48 1.77 1.85 1.57 1.51 1.55 1.46 1.65 1.47 1.61 1.48 1.51 1.50 CaO 21.95 21.83 22.36 22.27 22.28 22.29 21.67 21.31 21.35 21.47 21.33 21.61 21.21 20.96 MgO 13.11 14.11 15.98 24.46 16.85 16.75 20.53 19.83 16.57 16.53 16.70 16.66 18.23 16.83 15.65 15.81 15.99 16.12 14.22 13.93 14.08 13.65 14.19 14.07 14.02 13.98 14.01 13.95 14.17 13.88 O 2 K 0.01 0.01 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.01 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.02 0.00 0.01 Cl 0.01 0.01 0.01 0.01 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.00 0.00 O 2 0.02 0.03 0.02 0.03 0.06 0.05 0.02 0.03 0.02 0.02 0.01 0.02 0.03 0.01 0.04 0.05 0.44 0.52 0.48 0.54 0.51 0.53 0.43 0.48 0.42 0.43 0.47 0.45 0.41 0.42 Na F 0.11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.07 0.00 0.00 0.01 0.04 0.00 0.00 0.00 0.00 0.00

Probe 59CC2 59CD2 59CE1 59CE2 59CF1 59CF2 59CG1 59CG2 59CH1 59CH2 59CR1 59CR2 59CS1 59CS2 59CU1 59CU2 920CAD1 920CAD2 920CR1 920CR2 920CZ1 920CZ2 921CAD1 921CAD2 921CT1 921CT2 921CX1 921CX2 921CY1 921CY2 sample no. Unit Compositions (in Weight Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Nye County, Range, Nye County, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions for Pyroxene in Samples of Tertiary Compositions (in Weight Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson Canyon Megabreccia of Jefferson

Original sample no. DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-87-59 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-20 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 DRS-92-1 Appendix 7. Nevada.—Continued

Appendix 8 97 5.1 5.2 2.2 5.7 3.2 3.4 3.3 5.9 6.3 6.1 5.9 3.5 4.4 3.5 4.4 3.3 5.5 65.4 65.7 69.3 69.8 66.1 68.2 66.7 67.2 65.9 68.8 66.7 70.2 66.5 67.3 68.5 69.9 61.5 63.9 63.7 61.6 66.9 64.1 63.6 62.3 63.7 62.0 64.8 62.4 61.8 63.4 63.7 64.2 OR mol 33.4 33.2 29.9 29.1 32.8 30.8 32.4 31.8 33.0 30.5 32.4 28.9 32.4 31.7 30.5 29.1 65.7 65.9 54.6 71.5 58.8 58.9 59.1 75.0 73.6 72.6 71.8 57.0 61.2 56.5 61.2 61.6 71.4 37.3 35.0 35.3 37.0 32.2 34.6 35.6 36.5 35.4 36.6 34.0 36.4 36.9 35.2 35.2 34.8 AB mol 1.2 1.1 0.8 1.1 1.0 1.0 0.9 1.0 1.1 0.7 0.8 0.9 1.1 1.0 1.0 1.0 1.2 1.1 1.0 1.3 0.9 1.3 0.8 1.1 0.9 1.4 1.2 1.2 1.3 1.3 1.0 1.1 29.1 28.8 43.2 22.8 38.0 37.7 37.6 19.1 20.0 21.3 22.2 39.5 34.4 40.0 34.3 35.1 23.0 AN mol 98.75 98.99 99.69 99.70 98.92 99.63 98.77 98.81 99.62 99.26 99.38 99.51 99.48 99.32 99.06 99.12 99.36 99.33 99.83 99.29 99.02 99.33 99.42 98.94 98.63 98.68 98.91 98.85 98.72 98.40 98.48 98.31 98.93 99.17 99.85 99.04 99.11 98.27 99.22 99.16 99.47 99.39 99.82 99.86 99.60 98.51 99.31 98.96 99.22 Total Total 3 O 2 0.11 0.11 0.11 0.11 0.11 0.11 0.15 0.12 0.14 0.12 0.13 0.13 0.07 0.08 0.12 0.14 0.09 0.08 0.07 0.28 0.28 0.23 0.18 0.29 0.28 0.29 0.17 0.19 0.22 0.22 0.34 0.29 0.31 0.32 0.22 0.21 0.13 0.10 0.13 0.17 0.22 0.07 0.12 0.09 0.16 0.10 0.13 0.06 0.15 Fe 2 SiO 65.24 65.14 64.14 63.08 64.35 64.97 64.91 65.20 65.76 65.27 65.70 65.65 65.64 64.67 65.26 65.23 60.18 60.29 56.59 62.01 57.59 58.24 58.12 62.73 62.54 62.13 61.81 57.08 58.69 57.20 58.54 58.03 61.44 65.37 65.66 65.40 65.24 64.51 65.25 65.34 65.59 65.87 65.50 65.67 64.94 64.60 65.48 65.46 65.44 3 O 2 Al 18.35 18.46 18.96 19.28 18.70 18.63 18.49 18.38 18.47 18.43 18.32 18.39 18.62 18.74 18.39 18.47 24.08 24.09 26.98 22.94 25.70 25.67 25.77 22.17 22.10 22.40 22.69 25.76 24.64 25.46 24.54 25.05 23.02 18.67 18.65 18.56 18.69 18.40 18.67 18.49 18.50 18.52 18.83 18.67 19.02 18.43 18.53 18.34 18.55 CaO 0.24 0.22 0.16 0.21 0.21 0.19 0.18 0.20 0.23 0.14 0.17 0.18 0.22 0.20 0.20 0.20 6.08 5.96 9.07 4.78 7.94 7.79 7.81 4.05 4.18 4.45 4.67 8.30 7.10 8.24 7.12 7.27 4.87 0.24 0.22 0.20 0.26 0.19 0.27 0.16 0.23 0.19 0.29 0.24 0.24 0.25 0.27 0.21 0.21 0.11 BaO 0.17 0.10 1.73 2.84 1.06 1.03 0.03 0.09 0.02 0.56 0.14 0.23 0.01 0.93 0.22 0.19 0.15 0.16 0.12 0.08 0.07 0.04 0.02 0.00 0.01 0.01 0.12 0.02 0.14 0.17 0.05 0.07 0.10 0.56 0.00 0.48 0.05 0.26 0.19 0.21 0.03 0.85 0.29 0.98 0.51 0.52 0.07 0.41 SrO 0.11 0.11 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.12 0.12 0.00 0.09 0.00 0.05 0.00 0.00 0.00 0.00 0.12 0.05 0.00 0.09 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 O 2 K 1.11 0.90 0.91 0.39 1.00 0.56 0.59 0.58 1.05 1.08 1.05 0.62 0.77 0.61 0.77 0.57 0.99 11.22 11.37 11.06 11.32 11.39 11.34 11.34 11.41 11.32 11.74 11.27 11.19 11.52 11.74 11.40 11.07 10.93 10.92 10.48 10.76 10.83 10.25 10.78 10.87 10.63 10.78 10.25 10.30 10.45 10.54 10.87 10.66 O 2 4.11 3.67 3.73 3.23 3.04 3.57 3.36 3.64 3.53 3.73 3.33 3.62 3.18 3.61 3.47 3.38 3.22 7.58 7.53 6.33 8.29 6.78 6.72 6.78 8.78 8.50 8.39 8.34 6.62 6.98 6.42 7.02 7.04 8.34 4.18 3.88 3.95 4.05 3.61 3.83 4.00 4.10 3.94 3.98 3.82 3.96 3.85 3.95 3.80 Na

Probe 168K10C1 168K10R1 168K11C1 168K11R1 168K12C1 168K12R1 168K16C1 168K16R1 168K1C1 168K1R1 168K6C1 168K6R1 168K7C1 168K7R1 168K9C1 168K9R1 168P13C1 168P13R1 168P14C1 168P14R1 168P15C1 168P15R1 168P15R1 168P2C1 168P2R1 168P3C1 168P3R1 168P4C1 168P4R1 168P5C1 168P5R1 168P8C1 168P8R1 21K10C1 21K10R1 21K11C1 21K11R1 21K17C1 21K17R1 21K18C1 21K18R1 21K21C1 21K21R1 21K22C1 21K22R1 21K3C1 21K3R1 21K4C1 21K4R1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-168 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 Appendix 8. Nevada.—Continued Nye County, 98 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 3.5 4.2 7.4 7.5 5.6 5.7 5.6 5.0 3.2 5.9 5.6 7.5 5.8 5.5 6.5 6.0 5.0 5.5 2.4 3.9 6.8 6.9 4.3 3.0 3.4 5.7 4.7 2.2 5.2 66.6 64.2 65.2 63.4 62.9 61.5 60.9 59.6 64.9 63.1 67.4 59.3 64.2 61.3 61.9 60.0 59.8 65.1 63.2 59.1 OR mol 32.4 34.5 33.8 35.5 60.2 67.4 74.3 73.7 69.0 70.3 70.4 70.3 61.7 70.1 70.4 73.5 70.1 70.1 71.0 71.1 68.8 70.9 56.3 64.7 72.6 72.6 65.7 59.2 61.4 70.1 68.6 54.6 70.5 36.2 37.2 38.0 38.9 34.2 35.6 31.7 39.0 34.7 37.0 37.3 38.7 38.9 34.1 35.5 39.6 AB mol 1.1 1.3 1.0 1.1 0.9 1.3 1.1 1.4 1.0 1.3 0.8 1.7 1.1 1.7 0.8 1.3 1.3 0.8 1.3 1.3 36.3 28.3 18.3 18.8 25.4 24.0 24.0 24.6 35.1 24.0 23.9 19.0 24.2 24.3 22.6 22.9 26.2 23.5 41.3 31.4 20.6 20.5 30.0 37.8 35.2 24.2 26.8 43.3 24.3 AN mol 99.44 99.76 99.27 99.25 99.51 99.30 99.07 99.14 98.41 98.73 98.69 98.84 99.88 98.72 98.70 98.67 99.19 99.37 99.74 99.59 98.77 98.74 98.68 98.96 99.05 99.45 98.62 98.32 99.14 99.12 99.31 99.71 Total Total 100.34 100.16 100.03 100.14 100.10 100.56 100.41 100.57 101.14 100.93 100.90 100.99 101.29 100.86 100.73 100.70 100.52 3 O 2 0.11 0.11 0.11 0.08 0.15 0.10 0.08 0.18 0.19 0.17 0.16 0.26 0.22 0.23 0.20 0.19 0.21 0.25 0.25 0.24 0.22 0.25 0.22 0.21 0.19 0.27 0.25 0.21 0.19 0.30 0.17 0.24 0.26 0.23 0.22 0.21 0.08 0.09 0.14 0.07 0.13 0.16 0.12 0.08 0.09 0.09 0.07 0.09 0.08 Fe 2 SiO 65.58 65.03 65.37 65.56 58.48 60.44 62.98 62.68 60.50 61.07 61.23 61.34 59.13 61.47 61.53 62.48 61.49 61.63 62.75 62.55 61.54 62.20 57.47 59.88 62.33 62.34 59.81 57.84 58.25 61.90 60.41 55.99 61.48 66.07 66.42 66.49 65.95 66.94 66.88 66.69 66.65 66.78 66.08 66.74 66.74 65.53 65.86 66.56 65.32 3 O 2 Al 23.11 23.11 18.49 18.78 18.68 18.53 25.51 24.10 22.14 22.32 23.31 23.19 25.32 22.82 22.75 21.91 23.16 23.18 23.18 23.27 23.91 23.20 26.67 24.77 22.28 22.23 24.01 25.62 25.30 23.09 23.60 26.47 23.20 18.95 18.81 18.85 19.07 18.87 18.85 18.68 19.02 18.92 19.20 18.65 18.86 18.72 18.52 18.68 18.87 CaO 5.11 0.21 0.26 0.20 0.22 7.48 5.96 3.83 3.99 5.32 5.04 5.01 5.16 7.36 5.04 5.00 4.02 5.10 5.13 4.74 4.81 5.47 4.92 8.56 6.48 4.31 4.30 6.24 7.86 7.39 5.08 5.59 8.97 0.18 0.27 0.22 0.29 0.20 0.26 0.17 0.34 0.23 0.35 0.17 0.27 0.27 0.17 0.26 0.27 0.11 BaO 0.22 1.10 0.07 0.02 0.22 0.03 0.03 0.04 0.06 0.00 0.01 0.00 0.12 0.01 0.04 0.04 0.00 0.06 0.03 0.00 0.07 0.05 0.08 0.04 0.04 0.03 0.06 0.06 0.01 0.06 0.03 0.03 0.00 0.39 0.14 0.76 0.05 0.22 0.01 0.34 0.18 0.63 0.02 0.00 0.00 0.04 0.09 0.76 SrO 0.00 0.00 0.00 0.00 0.17 0.00 0.00 0.00 0.00 0.03 0.01 0.00 0.02 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.03 0.01 0.18 0.09 0.00 0.00 0.00 0.06 0.09 0.00 0.00 0.01 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 K 0.61 0.75 1.31 1.33 0.98 1.01 0.98 0.89 0.57 1.03 0.99 1.34 1.02 0.98 1.15 1.06 0.88 0.97 0.42 0.68 1.20 1.22 0.75 0.53 0.60 1.00 0.82 0.38 0.91 11.26 11.07 11.14 11.63 10.11 11.12 10.67 10.85 10.75 10.41 10.35 10.05 10.64 10.38 10.80 10.35 10.16 10.90 10.83 10.01 O 2 8.11 8.11 3.60 3.77 3.78 3.99 6.86 7.84 8.61 8.62 7.99 8.17 8.14 7.16 8.14 8.14 8.61 8.18 8.17 8.24 8.25 7.93 8.20 6.46 7.37 8.40 8.42 7.55 6.81 7.12 7.91 6.25 8.19 4.07 4.14 4.25 4.32 3.86 3.95 3.60 4.37 3.95 4.12 4.28 4.39 4.35 3.76 4.01 4.41 Na

Probe 21K5C1 21K5R1 21K9C1 21K9R1 21P12C1 21P12R1 21P15C1 21P15R1 21P16C1 21P16R1 21P19C1 21P19R1 21P1aC1 21P1aR1 21P1bC1 21P1bR1 21P20C1 21P20R1 21P23C1 21P23R1 21P24C1 21P24R1 21P25C1 21P25R1 21P2C1 21P2R1 21P6C1 21P6C2 21P6C2 21P6R1 21P8C1 21P8C2 21P8R1 24K10C1 24K10R1 24K11C1 24K11R1 24K15C1 24K15R1 24K17C1 24K17R1 24K23C1 24K23R1 24K28C1 24K28R1 24K4C1 24K5C1 24K5R1 24K7C1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight Tuff of Ryecroft Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff

Original sample no. DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-21 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 Appendix 8. Nevada.—Continued Nye County, Appendix 8 99 4.3 5.1 6.5 5.8 6.8 4.1 6.1 6.4 5.8 5.4 5.1 4.3 5.7 6.1 6.0 6.3 7.3 6.2 6.4 5.2 5.6 5.6 6.2 5.6 4.5 4.0 5.3 6.1 59.9 61.4 55.8 17.3 46.7 49.5 49.8 48.6 48.0 48.7 43.8 49.0 43.4 54.2 57.5 58.1 59.3 53.4 59.6 60.3 56.9 OR mol 38.8 37.7 42.2 65.2 68.0 71.3 69.5 71.9 65.7 70.7 71.5 71.5 68.6 68.0 66.0 69.9 70.0 70.1 71.6 72.4 71.5 71.8 68.3 70.9 70.4 71.2 70.0 66.1 64.0 69.8 71.6 75.6 51.6 48.9 48.4 49.5 50.3 49.6 53.9 49.1 54.5 42.2 40.6 40.7 38.9 44.4 38.2 38.3 40.8 AB mol 1.3 0.9 2.0 7.1 1.7 1.5 1.8 1.8 1.7 1.6 2.3 2.0 2.2 3.6 1.9 1.2 1.8 2.1 2.3 1.4 2.3 30.4 26.9 22.2 24.7 21.4 30.2 23.2 22.1 22.7 26.0 26.8 29.7 24.4 23.9 23.9 22.1 20.2 22.3 21.7 26.5 23.5 23.9 22.5 24.4 29.4 32.0 25.0 22.3 AN mol 98.81 98.95 99.63 99.83 99.52 99.62 99.40 99.64 99.32 99.28 99.21 99.85 99.91 99.56 99.17 99.53 Total Total 100.04 100.33 100.79 100.75 101.19 100.62 100.72 100.89 100.05 100.63 100.99 100.48 100.50 100.65 100.98 100.76 100.95 100.86 101.12 101.16 100.91 101.03 101.00 100.18 100.06 100.19 100.30 100.22 100.22 100.12 100.14 100.07 100.28 3 O 2 0.11 0.14 0.13 0.10 0.25 0.30 0.18 0.19 0.23 0.25 0.25 0.24 0.23 0.24 0.24 0.22 0.22 0.26 0.27 0.28 0.17 0.21 0.23 0.25 0.24 0.24 0.22 0.21 0.25 0.26 0.20 0.23 0.10 0.14 0.12 0.15 0.13 0.07 0.16 0.12 0.10 0.15 0.16 0.12 0.14 0.14 0.15 0.27 0.15 Fe 2 SiO 65.65 66.37 65.22 60.94 62.31 63.24 62.89 63.46 60.51 63.03 61.85 61.93 62.22 61.98 60.90 62.79 62.92 62.79 63.25 63.78 63.56 63.53 62.13 63.02 62.78 62.62 62.09 60.71 59.91 61.42 62.64 65.77 66.74 66.24 66.04 66.63 66.69 66.14 66.59 65.83 66.66 63.20 64.96 65.50 65.81 65.20 63.04 63.95 63.54 3 O 2 Al 23.11 19.11 18.83 18.74 19.59 24.69 24.06 23.21 23.45 24.60 23.27 22.85 22.78 24.22 23.93 24.67 23.44 23.58 23.43 23.24 22.85 23.22 23.14 24.02 23.65 23.72 23.22 23.26 24.24 24.61 23.55 23.16 20.04 18.95 18.85 18.77 19.08 18.98 18.75 18.76 19.04 20.06 19.26 18.97 19.02 19.15 19.47 18.86 19.43 CaO 5.11 0.26 0.18 0.39 6.43 5.66 4.64 5.14 4.49 6.28 4.85 4.57 4.70 5.43 5.59 6.22 5.02 5.00 4.67 4.28 4.68 4.62 5.54 4.92 5.01 4.74 5.03 6.14 6.66 5.27 4.67 1.50 0.36 0.32 0.36 0.38 0.34 0.33 0.48 0.41 0.45 0.68 0.39 0.23 0.37 0.43 0.44 0.27 0.45 0.11 0.11 BaO 0.85 0.19 1.61 0.06 0.05 0.00 0.02 0.07 0.14 0.00 0.02 0.04 0.00 0.05 0.00 0.00 0.10 0.03 0.02 0.05 0.06 0.09 0.03 0.00 0.09 0.06 0.03 0.10 0.00 0.04 0.05 0.06 0.00 0.05 0.03 0.00 0.05 0.06 0.06 2.84 1.09 0.80 0.33 0.90 2.70 1.85 2.53 SrO 0.00 0.00 0.07 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.01 0.04 O 2 9.22 0.77 0.90 1.14 1.02 1.19 0.72 1.07 1.11 1.01 0.94 0.90 0.76 1.00 1.08 1.05 1.12 1.30 1.10 1.15 0.92 0.98 0.99 1.10 0.98 0.79 0.70 0.94 1.08 3.08 8.08 8.52 8.54 8.40 8.33 8.37 7.65 8.46 7.56 8.73 9.70 9.73 9.10 9.63 9.84 9.10 K 10.03 10.48 10.20 O 2 4.28 4.24 4.59 7.62 7.90 8.22 8.01 8.34 7.54 8.16 8.16 8.19 7.90 7.84 7.63 8.09 8.12 8.12 8.37 8.46 8.30 8.43 7.90 8.19 8.15 8.28 7.98 7.62 7.35 8.14 8.28 8.86 5.87 5.54 5.46 5.63 5.74 5.61 6.19 5.58 6.25 4.47 4.51 4.49 4.41 4.98 4.06 4.12 4.29 Na

Probe 24K7R1 24K9C1 24K9R1 24P12C1 24P12R1 24P13C1 24P13R1 24P13R2 24P18C1 24P18R1 24P1C1 24P1R1 24P21aC1 24P21aR1 24P21bC1 24P21bR1 24P22aC1 24P22aR1 24P24C1 24P24R1 24P26C1 24P26R1 24P33C1 24P33R1 24P33R1 24P3C1 24P3R1 24P6C1 24P6R1 24P8C1 24P8R1 25K?21C1 25K?21R1 25K12C1 25K12R1 25K1C1 25K1R1 25K24C1 25K24R1 25K26C1 25K26R1 25K31C1 25K31M1 25K31R1 25K32C1 25K32R1 25K33C1 25K33M1 25K33R1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight Tuff of Ryecroft Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Canyon of Ryecroft Tuff Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain

Original sample no. DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-24 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 Appendix 8. Nevada.—Continued Nye County, 100 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 7.7 8.2 8.0 6.4 7.1 6.2 6.0 5.2 8.4 6.9 6.4 6.4 8.3 6.2 4.6 6.5 4.0 3.8 4.6 3.7 1.0 46.7 44.9 57.3 55.2 47.9 47.7 47.0 47.9 44.0 46.4 22.5 21.1 65.8 60.2 64.0 56.6 66.2 59.1 64.9 57.9 65.3 61.0 62.4 61.1 65.2 57.3 61.8 60.4 OR mol 51.2 53.1 41.7 43.6 50.6 50.6 51.2 50.2 53.4 51.6 70.1 70.9 72.1 72.8 68.1 66.4 68.1 69.1 64.1 62.6 77.6 75.3 67.1 65.8 70.1 68.2 62.5 66.5 32.9 38.4 35.1 42.0 32.8 39.9 34.3 41.1 33.8 37.8 36.7 37.8 33.8 41.3 35.9 37.4 53.0 53.4 56.4 52.7 23.5 AB mol 2.0 1.9 1.0 1.2 1.6 1.7 1.9 2.0 2.6 2.0 7.4 8.1 1.3 1.4 0.9 1.4 1.0 1.0 0.9 1.0 0.9 1.2 0.9 1.1 1.1 1.4 2.3 2.2 20.1 19.0 23.9 27.2 24.8 24.7 29.9 32.2 14.0 17.9 26.5 27.8 21.6 25.6 33.0 27.0 43.0 42.8 39.0 43.6 75.6 AN mol 99.48 99.63 99.98 99.98 99.23 99.76 99.05 99.79 99.99 99.92 99.63 99.19 99.30 99.49 99.50 99.53 99.73 99.77 99.70 99.49 99.85 99.88 99.50 99.50 99.32 99.12 99.59 99.71 99.81 99.69 99.28 99.91 99.98 98.82 98.96 98.96 98.84 98.55 Total Total 100.14 100.09 100.19 100.27 100.04 100.37 100.04 100.16 100.18 100.02 100.41 3 O 2 0.11 0.11 0.11 0.11 0.11 0.17 0.10 0.07 0.12 0.15 0.16 0.13 0.15 0.16 0.20 0.24 0.26 0.32 0.26 0.26 0.33 0.34 0.30 0.17 0.18 0.26 0.33 0.23 0.25 0.26 0.31 0.09 0.07 0.13 0.13 0.17 0.12 0.09 0.24 0.16 0.24 0.09 0.18 0.07 0.30 0.35 0.37 0.35 0.62 Fe 2 SiO 66.58 66.18 66.15 65.97 66.33 66.50 66.65 66.47 65.97 66.38 65.49 65.68 62.99 63.44 61.72 61.20 61.01 61.36 59.97 59.34 64.42 64.00 60.93 60.66 62.50 61.14 59.67 60.99 65.47 65.61 65.98 66.52 65.45 65.94 65.84 65.70 65.96 65.77 66.14 66.26 66.15 66.41 64.26 64.55 56.90 56.74 57.77 56.60 48.64 3 O 2 Al 18.98 18.86 18.84 18.80 19.07 18.99 18.96 18.82 18.95 18.91 20.01 20.27 22.65 22.44 23.15 23.96 23.37 23.35 24.20 24.90 21.34 22.39 23.78 23.93 22.89 23.63 25.05 24.03 18.70 18.74 18.39 18.76 18.47 18.58 18.53 18.79 18.56 18.52 18.69 18.64 18.70 18.76 19.51 19.45 26.21 26.35 25.52 26.39 31.54 0.42 0.40 0.20 0.24 0.33 0.35 0.39 0.40 0.54 0.41 1.52 1.69 4.24 3.96 4.95 5.64 5.19 5.13 6.11 6.65 2.96 3.78 5.58 5.83 4.48 5.37 6.87 5.65 0.25 0.28 0.18 0.28 0.20 0.20 0.18 0.20 0.18 0.25 0.19 0.21 0.21 0.29 0.44 0.44 8.67 8.67 7.94 8.75 CaO 14.98 0.11 0.11 0.11 0.11 0.11 0.11 0.11 BaO 0.06 0.01 0.06 0.03 0.08 0.08 0.02 0.00 0.01 0.06 0.01 0.33 0.26 0.26 0.52 0.26 0.07 0.00 0.20 0.24 0.13 0.00 0.08 0.47 0.55 0.02 0.00 0.04 0.21 0.22 0.33 0.12 0.03 0.26 0.24 0.09 0.04 1.80 1.65 0.09 0.14 0.00 SrO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.08 0.01 0.00 0.00 0.04 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.09 0.10 0.13 0.14 0.04 O 2 8.09 7.84 9.98 9.53 8.29 8.32 8.23 8.30 7.58 7.96 3.89 3.70 1.37 1.43 1.39 1.12 1.24 1.07 1.03 0.90 1.50 1.22 1.13 1.13 1.44 1.09 0.80 1.15 9.64 9.70 0.67 0.65 0.78 0.63 0.16 K 11.20 11.02 10.92 10.01 10.79 10.07 10.96 10.00 10.28 10.61 10.37 10.94 10.04 10.13 O 2 4.11 5.84 6.10 4.78 4.95 5.76 5.80 5.90 5.72 6.06 5.83 7.97 8.19 8.39 8.38 7.78 7.60 7.86 7.93 7.24 7.15 9.07 8.80 7.81 7.64 8.03 7.90 7.20 7.68 3.59 4.21 3.89 4.71 3.65 4.47 3.81 4.67 3.76 4.19 4.22 3.73 4.60 3.84 4.12 5.90 5.98 6.34 5.84 2.57 Na

Probe 25K3C1 25K3R1 25K4C1 25K4R1 25K5C1 25K5R1 25K6C1 25K6R1 25K8C1 25K8R1 25P?13C1 25P?13R1 25P?14C1 25P?14R1 25P?15C1 25P?15R1 25P10C1 25P10R1 25P11C1 25P11R1 25P16C1 25P16R1 25P18C1 25P18R1 25P28C1 25P28R1 25P2C1 25P2R1 34K11C1 34K11R1 34K18C1 34K18R1 34K29C1 34K29R1 34K32C1 34K32R1 34K33C1 34K33R1 34K35C1 34K35R1 34K36C1 34K36R1 34K37C1 34K37R1 34P13C1 34P13C2 34P13R1 34P13R2 34P14C1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-91-25 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 Appendix 8. Nevada.—Continued Nye County, Appendix 8 101 1.3 0.9 1.2 0.9 0.9 1.0 4.3 4.6 4.6 5.0 4.2 4.4 3.0 3.5 3.8 4.5 4.3 0.9 1.2 5.2 4.3 4.6 3.9 0.9 1.1 1.1 1.0 1.8 2.0 1.1 0.9 1.1 1.1 1.1 1.0 4.2 4.0 1.1 1.0 1.1 1.2 45.5 45.7 47.2 47.4 46.9 49.8 50.7 46.9 OR mol 26.5 23.0 25.3 23.4 25.6 23.9 54.8 57.6 57.2 57.5 56.0 54.5 48.4 52.7 54.3 56.0 56.6 19.8 22.1 59.0 56.5 57.0 53.8 24.4 24.2 27.2 25.5 34.6 37.2 25.2 21.4 24.7 25.8 25.4 22.8 56.1 55.1 23.7 24.5 27.7 26.4 52.2 52.2 50.8 50.6 51.4 48.5 47.5 51.2 AB mol 2.3 2.1 2.0 1.9 1.7 1.8 1.8 1.9 72.2 76.1 73.5 75.8 73.5 75.0 40.9 37.8 38.1 37.5 39.9 41.1 48.5 43.8 42.0 39.5 39.1 79.3 76.6 35.8 39.2 38.4 42.3 74.7 74.7 71.7 73.5 63.6 60.8 73.6 77.6 74.2 73.1 73.4 76.2 39.6 40.8 75.2 74.5 71.2 72.4 AN mol 98.40 98.79 98.70 98.59 99.05 98.57 98.40 99.01 98.97 99.01 99.37 98.54 98.58 99.19 99.23 99.32 99.54 99.42 99.20 99.78 99.35 99.85 99.53 99.42 99.25 99.35 99.56 99.45 99.15 99.52 99.39 99.65 99.55 99.40 99.24 98.99 99.51 99.44 99.50 99.77 99.71 99.99 98.29 Total Total 100.01 100.06 100.26 100.16 100.31 100.11 3 O 2 0.11 0.57 0.59 0.59 0.61 0.64 0.54 0.36 0.32 0.28 0.31 0.38 0.37 0.28 0.35 0.33 0.36 0.33 0.61 0.63 0.28 0.31 0.37 0.34 0.61 0.62 0.52 0.58 0.53 0.59 0.55 0.57 0.63 0.68 0.60 0.64 0.33 0.34 0.58 0.63 0.56 0.59 0.15 0.14 0.13 0.16 0.14 0.16 0.15 Fe 2 SiO 49.33 48.51 48.89 48.49 49.27 48.66 57.01 57.82 57.92 58.28 57.86 57.33 55.04 56.48 57.04 57.87 57.87 47.85 48.40 59.15 57.74 58.21 57.08 48.83 48.92 49.71 49.24 51.75 52.24 49.28 48.43 49.26 49.21 48.92 48.64 57.71 57.48 48.37 48.86 49.69 49.35 65.86 66.41 66.20 66.72 66.76 66.46 66.51 65.23 3 O 2 Al 30.95 31.74 31.28 31.43 31.40 31.52 25.73 25.59 25.63 25.27 25.80 25.77 27.14 26.47 26.22 25.75 25.78 32.54 31.97 25.26 25.84 25.93 26.42 31.93 31.78 31.26 31.57 29.87 29.38 31.66 32.37 31.71 31.75 31.69 31.98 26.25 26.52 31.87 31.90 31.34 31.58 19.09 19.20 18.85 18.94 18.91 18.93 18.95 18.65 8.23 7.65 7.70 7.56 8.10 8.15 9.86 8.95 8.58 8.02 8.05 7.30 8.09 7.84 8.70 8.26 8.44 0.48 0.44 0.41 0.40 0.36 0.36 0.37 0.39 CaO 14.32 15.14 14.76 15.21 14.68 14.93 15.93 15.42 14.98 14.96 14.46 14.97 12.92 12.27 14.84 15.42 15.00 14.68 14.99 15.16 15.21 15.05 14.44 14.66 0.11 0.11 0.11 0.11 BaO 0.03 0.02 0.08 0.05 0.00 0.02 0.28 0.15 0.23 0.14 0.15 0.20 0.17 0.27 0.05 0.01 0.12 0.10 0.18 0.08 0.00 0.08 0.03 0.03 0.05 0.04 0.06 0.03 0.05 0.06 0.09 0.15 0.15 0.05 0.05 0.01 0.03 0.07 0.05 0.00 0.00 0.12 0.06 0.07 0.03 SrO 0.11 0.11 0.11 0.11 0.11 0.11 0.08 0.10 0.09 0.06 0.08 0.09 0.14 0.14 0.12 0.12 0.15 0.18 0.17 0.08 0.07 0.09 0.10 0.13 0.08 0.13 0.10 0.10 0.13 0.15 0.12 0.15 0.02 0.07 0.13 0.09 0.05 0.13 0.08 0.10 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 K 0.21 0.16 0.19 0.15 0.15 0.17 0.73 0.77 0.79 0.85 0.71 0.73 0.52 0.60 0.65 0.78 0.75 0.15 0.21 0.90 0.74 0.78 0.67 0.15 0.18 0.19 0.17 0.31 0.35 0.19 0.16 0.20 0.18 0.19 0.16 0.74 0.70 0.19 0.18 0.19 0.20 8.05 8.01 8.27 8.19 8.15 8.55 8.72 8.05 O 2 6.11 2.91 2.53 2.81 2.59 2.83 2.63 6.09 6.44 6.39 6.40 6.28 5.97 5.44 5.96 6.13 6.29 6.43 2.20 2.46 6.65 6.45 6.43 2.71 2.68 3.03 2.87 3.89 4.15 2.81 2.35 2.76 2.86 2.87 2.51 6.47 6.30 2.65 2.73 3.10 2.96 6.07 6.01 5.85 5.75 5.88 5.48 5.38 5.78 Na

Probe 34P14M1 34P14R1 34P14R2 34P15C1 34P15M1 34P15R1 34P16C1 34P16C2 34P16M1 34P16M2 34P16R1 34P16R2 34P17C1 34P17M1 34P17M2 34P17R1 34P17R2 34P19C1 34P19R1 34P20C1 34P20M1 34P20R1 34P20R2 34P21C1 34P21R1 34P22C1 34P22R1 34P23C1 34P23R1 34P24C1 34P24R1 34P26C1 34P26R1 34P27C1 34P27R1 34P28C1 34P28R1 34P30C1 34P30R1 34P31C1 34P31R1 3K10C1 3K10R1 3K11C1 3K11R1 3K11R1 3K12C1 3K12R1 3K13C1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Isom-type tuff Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-84-34 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 Appendix 8. Nevada.—Continued Nye County, 102 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 5.7 5.7 2.6 2.4 1.6 1.5 3.6 6.5 46.1 47.2 46.4 46.8 46.5 47.5 47.6 47.5 47.4 47.2 47.6 46.3 46.3 49.9 49.5 64.0 63.9 62.8 62.8 63.7 64.8 64.8 64.7 63.3 64.1 63.2 64.7 65.1 64.4 65.1 63.3 65.6 66.5 64.4 64.8 62.6 65.3 64.7 64.5 62.6 63.8 OR mol 51.8 50.7 51.5 51.4 51.8 50.6 50.5 50.5 50.6 50.9 50.6 52.0 51.7 48.5 48.8 62.3 61.8 52.1 49.3 42.0 48.7 61.3 71.3 34.8 34.8 36.1 35.9 35.3 34.3 34.0 34.3 35.4 34.8 35.8 34.1 33.6 34.2 33.8 35.7 33.3 32.7 34.5 33.9 36.4 33.6 34.4 34.3 36.2 35.0 AB mol 2.1 2.1 2.1 1.9 1.7 1.9 1.9 1.9 2.0 1.9 1.7 1.7 2.0 1.6 1.7 1.2 1.3 1.1 1.3 1.0 1.0 1.2 1.0 1.3 1.1 1.1 1.2 1.3 1.3 1.1 0.9 1.1 0.8 1.2 1.2 1.0 1.1 0.8 1.2 1.2 1.2 32.1 32.5 45.4 48.3 56.5 49.9 35.0 22.1 AN mol 98.95 99.10 99.33 99.46 99.08 99.76 98.94 98.25 99.13 99.72 99.82 99.06 99.13 99.74 99.58 99.31 99.61 98.50 99.00 99.54 99.68 98.18 98.16 98.47 98.29 98.14 99.07 98.66 99.30 98.13 98.79 98.94 98.53 98.17 98.04 97.94 98.49 98.23 97.45 Total Total 100.11 100.12 101.55 100.98 100.86 100.52 100.80 100.95 100.69 100.63 3 O 2 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.15 0.13 0.13 0.16 0.13 0.14 0.14 0.13 0.17 0.10 0.16 0.17 0.14 0.17 0.12 0.28 0.40 0.27 0.33 0.34 0.19 0.18 0.24 0.09 0.09 0.07 0.12 0.12 0.15 0.10 0.14 0.09 0.12 0.08 0.14 0.05 0.10 0.21 0.10 0.13 0.08 0.12 Fe 2 SiO 65.64 65.81 66.14 66.17 65.75 66.19 66.78 65.55 64.96 65.86 66.21 66.23 65.79 65.95 66.37 59.80 59.42 55.96 55.23 52.43 54.65 58.89 62.41 66.12 65.86 66.88 66.78 66.95 66.92 64.72 64.80 64.04 64.87 66.65 66.48 63.93 62.99 64.79 65.69 64.21 64.91 65.21 63.79 64.53 64.12 64.13 64.82 64.30 63.89 3 O 2 Al 18.87 18.76 18.85 18.75 18.83 18.90 18.75 18.87 18.59 18.81 18.88 18.94 18.75 18.52 18.69 24.78 24.63 27.18 27.72 28.77 27.83 25.28 22.87 19.18 18.97 18.65 18.67 18.60 18.69 18.30 18.29 18.56 18.31 18.87 18.85 18.55 19.16 18.37 18.48 18.34 18.38 18.45 18.67 18.40 18.49 18.39 18.47 18.50 18.34 0.44 0.42 0.43 0.38 0.35 0.39 0.40 0.40 0.40 0.40 0.36 0.35 0.42 0.33 0.35 6.66 6.66 9.38 7.31 4.63 0.24 0.26 0.22 0.27 0.21 0.20 0.25 0.20 0.26 0.22 0.22 0.24 0.27 0.26 0.22 0.19 0.22 0.17 0.24 0.25 0.20 0.22 0.17 0.24 0.24 0.24 CaO 11.78 10.08 10.38 0.11 0.11 BaO 0.02 0.02 0.04 0.07 0.10 0.09 0.06 0.01 0.09 0.05 0.00 0.02 0.01 0.04 0.10 0.41 0.40 0.10 0.07 0.09 0.17 0.13 1.20 1.07 0.05 0.00 0.06 0.04 0.00 0.03 0.97 0.10 0.01 0.08 0.71 2.63 0.48 0.07 0.53 0.51 0.09 1.15 0.06 0.61 0.07 0.31 0.27 SrO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.09 0.02 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O 2 7.95 8.18 7.94 8.08 8.03 8.26 8.23 8.22 8.24 8.14 8.30 8.11 8.04 8.61 8.56 0.99 0.99 0.44 0.42 0.28 0.26 0.64 1.15 K 11.12 11.03 11.03 11.02 11.16 11.14 10.84 10.83 10.85 10.70 10.90 10.91 10.61 10.79 10.82 10.89 10.27 10.97 10.75 10.99 10.83 10.68 10.82 10.94 10.72 10.72 O 2 5.88 5.78 5.80 5.84 5.89 5.79 5.75 5.75 5.79 5.77 5.81 6.00 5.91 5.51 5.56 7.15 7.00 5.95 5.69 4.84 5.60 7.07 8.25 3.88 3.88 4.10 4.02 3.97 3.87 3.81 3.80 3.91 3.85 4.03 3.82 3.70 3.59 3.75 3.99 3.68 3.61 3.87 3.73 4.09 3.67 3.90 3.83 4.08 3.87 Na

Probe 3K13R1 3K14C1 3K14R1 3K15C1 3K15R1 3K18C1 3K18R1 3K1C1 3K1R1 3K20C1 3K20R1 3K2C1 3K2R1 3K9C1 3K9R1 3P16C1 3P16R1 3P21C1 3P21R1 3P4C1 3P4R1 3P8C1 3P8R1 44K16C1 44K16R1 44K17C1 44K17R1 44K18C1 44K18R1 44K1C1 44K1C2 44K1R1 44K1R2 44K23C1 44K23R1 44K2C1 44K2R1 44K2R2 44K3C1 44K3R1 44K3R2 44K4C1 44K4R1 44K5C1 44K5R1 44K6C1 44K6R1 44K7C1 44K7R1 sample no. plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain Tuff Bates Mountain of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-91-3 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 Appendix 8. Nevada.—Continued Nye County, Appendix 8 103 2.1 3.9 2.4 3.6 2.6 3.5 3.7 3.3 3.9 4.1 5.1 1.8 2.5 3.4 4.3 3.5 3.0 2.4 3.4 3.5 7.0 6.3 3.2 2.1 4.4 5.1 5.3 64.3 64.1 64.3 61.6 62.3 62.2 60.7 61.5 61.7 60.8 61.4 61.1 66.3 63.3 63.3 61.7 63.5 61.7 65.3 62.0 62.8 62.6 61.9 OR mol 34.6 34.6 49.2 64.7 50.8 63.2 51.4 63.4 60.6 62.6 65.3 66.2 70.4 41.9 47.6 59.4 63.1 66.6 57.2 53.2 56.9 62.7 73.8 74.1 58.8 55.7 35.0 36.9 36.6 36.6 37.6 36.8 36.7 37.5 36.7 36.8 32.7 35.2 35.6 36.7 35.7 36.8 33.6 36.6 36.1 36.5 36.8 56.3 60.0 60.5 AB mol 1.2 1.3 0.7 1.4 1.1 1.3 1.6 1.7 1.6 1.6 2.0 2.1 1.0 1.5 1.1 1.5 0.8 1.6 1.1 1.3 1.1 1.0 1.3 48.8 31.4 46.8 33.3 46.0 33.1 35.7 34.1 30.8 29.7 24.5 56.3 49.9 37.2 32.6 29.9 39.8 44.4 39.7 33.8 19.2 19.6 37.9 42.2 39.3 34.9 34.2 AN mol 97.72 98.35 99.04 99.45 99.55 99.95 99.96 99.56 99.58 99.94 99.68 99.67 99.45 99.69 99.50 99.70 99.65 99.47 99.10 99.04 Total Total 100.09 100.11 100.69 100.26 100.12 100.75 100.77 100.41 100.71 100.94 100.72 100.48 100.98 100.68 101.32 100.61 100.87 100.45 100.61 100.82 100.35 100.64 100.45 100.65 100.48 100.41 100.47 100.33 100.48 100.38 3 O 2 0.11 0.11 0.11 0.09 0.12 0.40 0.33 0.39 0.29 0.36 0.32 0.35 0.34 0.20 0.22 0.22 0.38 0.37 0.33 0.19 0.29 0.31 0.29 0.35 0.30 0.19 0.22 0.38 0.40 0.10 0.10 0.16 0.14 0.15 0.16 0.19 0.18 0.19 0.16 0.09 0.10 0.12 0.20 0.12 0.12 0.15 0.16 0.34 0.32 0.36 Fe 2 SiO 63.63 64.34 54.96 59.82 55.72 59.79 56.40 59.48 58.67 59.08 60.24 60.42 62.58 53.87 55.51 59.13 60.50 60.76 58.46 57.53 58.47 59.95 64.41 64.08 58.79 57.73 65.86 66.17 66.13 65.91 66.36 66.20 65.57 65.90 64.55 64.59 65.40 65.66 65.49 65.69 66.10 66.51 66.34 66.64 65.80 66.45 66.21 58.08 59.50 59.26 3 O 2 Al 18.57 18.59 27.32 24.45 27.14 24.87 26.99 24.93 25.08 24.86 24.60 24.42 23.62 28.99 27.93 25.62 25.00 24.41 26.24 27.13 26.14 25.12 22.47 22.57 26.39 26.72 18.54 18.43 19.07 18.99 18.25 18.51 18.66 18.53 19.10 19.05 18.58 18.48 18.99 19.07 18.83 18.85 18.70 18.76 18.92 18.65 18.85 26.23 25.32 25.34 0.24 0.25 6.49 9.82 6.94 9.56 7.00 7.52 7.19 6.51 6.23 5.14 7.85 6.84 6.30 8.31 9.27 8.28 7.03 4.04 4.10 7.97 8.73 0.15 0.28 0.22 0.25 0.32 0.34 0.32 0.32 0.38 0.39 0.21 0.30 0.22 0.31 0.17 0.32 0.22 0.27 0.23 0.20 0.27 8.12 7.24 7.10 CaO 11.67 10.04 10.25 0.11 BaO 0.47 0.48 0.19 0.15 0.08 0.18 0.14 0.10 0.16 0.12 0.16 0.22 0.09 0.08 0.17 0.10 0.18 0.10 0.08 0.19 0.17 0.06 0.06 0.23 0.17 0.40 0.39 0.78 0.71 0.04 0.08 0.64 0.64 1.58 1.54 0.09 0.06 1.38 1.15 0.32 0.37 0.00 0.07 0.75 0.03 0.10 0.18 0.24 0.32 SrO 0.11 0.00 0.00 0.19 0.13 0.10 0.14 0.09 0.08 0.10 0.07 0.03 0.00 0.13 0.14 0.12 0.05 0.08 0.16 0.09 0.15 0.12 0.00 0.00 0.16 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.20 0.09 0.15 O 2 0.36 0.68 0.42 0.62 0.46 0.63 0.65 0.59 0.70 0.73 0.89 0.31 0.43 0.60 0.76 0.63 0.53 0.43 0.59 0.60 1.24 1.10 0.57 0.37 9.94 9.84 0.77 0.89 0.92 K 11.12 11.26 10.88 10.75 10.77 10.25 10.46 10.42 10.18 10.33 10.15 10.05 10.58 10.52 10.35 10.83 10.40 10.63 10.61 10.82 10.73 O 2 3.85 3.82 5.59 7.40 5.88 7.28 5.91 7.41 7.05 7.31 7.63 7.67 8.15 4.80 5.40 6.93 7.33 7.76 6.61 6.13 6.55 7.20 8.57 8.55 6.83 6.36 3.86 4.04 4.05 4.03 4.15 4.07 3.97 4.08 3.91 3.90 3.61 3.87 3.89 4.05 4.00 4.08 3.81 4.13 4.01 4.15 4.20 6.42 6.87 6.93 Na

Probe 44K8C1 44K8R1 44P10C1 44P10R1 44P11C1 44P11R1 44P12C1 44P12R1 44P13C1 44P13R1 44P14C1 44P14M1 44P14R1 44P15C1 44P15M1 44P15R1 44P19C1 44P19R1 44P20C1 44P20R1 44P21C1 44P21R1 44P22C1 44P22R1 44P24C1 44P24R1 52K19C1 52K19R1 52K1C1 52K1R1 52K21C1 52K21R1 52K22C1 52K22R1 52K23C1 52K23R1 52K24C1 52K24R1 52K2C1 52K2R1 52K3C1 52K3R2 52K4C1 52K4R1 52K5C1 52K6C1 52K6R1 52P10C1 52P10M1 52P10R1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar k-spar Mineral Unit Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff of Mount Jefferson Tuff upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-85-44 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 Appendix 8. Nevada.—Continued Nye County, 104 Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada 4.8 4.7 3.1 4.1 4.6 4.1 4.3 4.9 5.1 5.0 4.4 5.4 4.9 6.1 5.1 4.8 4.6 4.1 4.3 4.8 5.1 4.6 4.8 5.1 4.4 2.1 5.5 5.7 4.7 4.5 5.1 4.2 3.9 4.0 4.2 4.6 6.2 6.7 4.0 4.2 3.8 5.6 4.8 7.7 4.9 6.6 5.4 4.8 6.1 7.3 OR mol 58.9 59.1 51.4 56.6 59.0 56.4 57.0 59.8 59.5 59.4 56.7 60.4 58.9 62.1 60.4 59.1 58.0 56.9 57.3 58.6 59.1 58.1 58.3 59.9 58.0 43.3 61.2 62.7 59.8 58.4 60.5 57.2 55.2 54.6 55.3 57.7 61.0 60.9 55.0 54.3 53.1 59.4 56.4 64.0 57.4 61.3 59.6 56.7 59.8 62.9 AB mol 36.3 36.3 45.5 39.3 36.3 39.5 38.8 35.2 35.3 35.6 38.9 34.2 36.1 31.8 34.5 36.1 37.4 39.0 38.4 36.6 35.8 37.4 36.9 35.0 37.6 54.6 33.3 31.6 35.5 37.1 34.4 38.5 40.9 41.4 40.4 37.7 32.8 32.4 41.0 41.5 43.1 35.1 38.9 28.4 37.6 32.1 35.0 38.5 34.1 29.7 AN mol 99.34 99.09 99.34 99.21 99.37 99.57 99.68 99.85 99.60 99.72 99.77 99.72 99.76 99.56 99.57 99.84 99.71 99.24 99.19 99.72 99.92 99.56 99.74 99.81 99.43 99.66 99.96 99.87 Total Total 100.62 100.40 100.13 100.03 100.12 100.48 100.60 100.20 100.40 100.39 100.30 100.39 100.12 100.55 100.17 101.12 100.85 100.27 100.21 100.12 100.11 100.78 3 O 2 0.31 0.32 0.33 0.37 0.32 0.33 0.36 0.31 0.31 0.33 0.34 0.32 0.32 0.27 0.30 0.35 0.34 0.31 0.38 0.33 0.29 0.36 0.34 0.32 0.33 0.34 0.34 0.26 0.34 0.36 0.32 0.33 0.37 0.27 0.32 0.33 0.30 0.37 0.39 0.41 0.27 0.39 0.37 0.36 0.31 0.36 0.35 0.36 0.27 0.30 Fe 2 SiO 59.06 58.94 56.22 57.56 58.42 57.51 57.91 58.98 59.04 59.05 58.36 59.20 59.15 59.91 59.15 58.97 58.59 57.87 58.26 58.89 59.08 58.39 58.44 58.96 58.52 53.94 59.40 59.89 58.81 58.59 59.08 58.35 57.66 57.77 58.05 58.63 59.77 59.79 57.58 57.16 57.34 59.08 58.73 60.98 58.52 59.87 58.81 58.13 59.35 60.74 3 O 2 Al 25.75 25.75 26.68 25.57 25.12 25.70 25.48 24.97 25.00 25.13 25.49 24.88 25.05 24.49 24.89 25.06 25.26 25.81 25.77 25.31 25.16 25.09 25.13 25.05 25.41 28.41 24.68 24.40 24.98 25.31 25.25 25.93 26.64 26.74 26.23 26.04 25.04 24.78 26.54 26.53 27.01 25.31 26.20 24.26 25.82 24.78 25.39 25.96 25.12 24.57 CaO 7.51 7.49 9.36 8.10 7.56 8.18 8.04 7.29 7.31 7.45 8.05 7.02 7.38 6.58 7.18 7.44 7.69 8.06 7.89 7.60 7.31 7.69 7.54 7.28 7.81 6.93 6.60 7.31 7.62 7.12 7.92 8.50 8.56 8.26 7.74 6.79 6.76 8.52 8.69 8.92 7.31 8.13 5.95 7.86 6.63 7.26 8.01 7.09 6.17 11.36 BaO 0.26 0.25 0.23 0.25 0.22 0.22 0.17 0.20 0.26 0.29 0.21 0.25 0.20 0.30 0.25 0.24 0.17 0.19 0.18 0.17 0.21 0.19 0.20 0.18 0.28 0.10 0.27 0.32 0.22 0.20 0.23 0.20 0.21 0.16 0.21 0.20 0.31 0.29 0.16 0.18 0.17 0.19 0.23 0.41 0.16 0.28 0.25 0.21 0.22 0.42 SrO 0.11 0.11 0.11 0.11 0.11 0.11 0.16 0.14 0.09 0.10 0.10 0.13 0.13 0.06 0.14 0.17 0.15 0.12 0.07 0.13 0.12 0.12 0.13 0.15 0.13 0.13 0.14 0.15 0.16 0.06 0.12 0.10 0.16 0.18 0.15 0.16 0.09 0.17 0.16 0.14 0.12 0.18 0.12 0.08 0.10 0.13 0.15 0.04 0.13 0.09 O 2 K 0.84 0.81 0.53 0.72 0.81 0.72 0.74 0.85 0.89 0.87 0.76 0.93 0.85 1.06 0.89 0.83 0.79 0.72 0.74 0.84 0.87 0.79 0.82 0.89 0.76 0.37 0.96 1.00 0.82 0.78 0.90 0.73 0.68 0.69 0.73 0.79 1.09 1.17 0.69 0.74 0.66 0.98 0.84 1.35 0.86 1.14 0.94 0.84 1.06 1.28 O 2 6.73 6.74 5.85 6.44 6.79 6.46 6.53 6.84 6.81 6.87 6.48 6.85 6.65 7.09 6.95 6.74 6.60 6.50 6.50 6.73 6.67 6.61 6.58 6.88 6.66 4.98 7.03 7.24 6.80 6.63 6.92 6.50 6.33 6.24 6.25 6.54 6.98 7.03 6.32 6.29 6.07 6.84 6.52 7.41 6.63 7.00 6.83 6.51 6.86 7.21 Na

Probe 52P11C1 52P11R1 52P12C1 52P12M1 52P12R1 52P13C1 52P13M1 52P13R1 52P14C1 52P14M1 52P14R1 52P15C1 52P15M1 52P15M2 52P15R1 52P15R2 52P16C1 52P16M1 52P16M2 52P16R1 52P16R2 52P17C1 52P17R1 52P18C1 52P18M1 52P20C1 52P20M1 52P20M2 52P20R1 52P20R2 52P7C1 52P7R1 52P8C1 52P8R1 52P9C1 52P9R1 59P15C1 59P15R1 59P16C1 59P16R1 59P17C1 59P18C1 59P4C1 59P4R1 59P5C1 59P5R1 59P6C1 59P6R1 59P7C1 59P7R1 sample no. plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag plag Mineral Unit Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, upper Isom-type tuff, Compositions (in Weight Percent) and End-Member Proportions of Plagioclase and Sanidine in Samples of Tertiary Igneous Rocks in the Southern Toquima Range, Igneous Rocks in the Southern Toquima Percent) and End-Member Proportions of Plagioclase Sanidine in Samples Tertiary Compositions (in Weight

Original sample no. DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 DRS-87-52 Appendix 8. Nevada.—Continued Nye County, Publishing support provided by: Denver Publishing Service Center, Denver, Colorado For more information concerning this publication, contact: Center Director, USGS Central Mineral and Environmental Resources Science Center Box 25046, Mail Stop 973 Denver, CO 80225 (303) 236-1562 Or visit the Central Mineral and Environmental Resources Science Center Web site at: http://minerals.cr.usgs.gov/ This publication is available online at: http://dx.doi.org/10.3133/sir20135206

Shawe and others—Tertiary Volcanic and Intrusive Rocks in Part of the Southern Toquima Range, Nye County, Nevada—Scientific Investigations Report 2013–5206 ISSN 2328-0328 (online) http://dx.doi.org/10.3133/sir20135206