DOCSLIB.ORG

Internal Fabrics of the Idaho Batholith, USA

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Internal Fabrics of the Idaho Batholith, USA THEMED ISSUE: EarthScope IDOR project (Deformation and Magmatic Modification of a Steep Continental Margin, Western Idaho–Eastern Oregon) Internal fabrics of the Idaho batholith, USA A. Byerly1, B. Tikoff1, M. Kahn1, B. Jicha1, R. Gaschnig2,*, and A.K. Fayon3 1DEPARTMENT OF GEOSCIENCE, UNIVERSITY OF WISCONSIN–MADISON, MADISON, WISCONSIN 53706, USA 2SCHOOL OF EARTH AND ATMOSPHERIC SCIENCE, GEORGIA INSTITUTE OF TECHNOLOGY, ATLANTA, GEORGIA 30332, USA 3DEPARTMENT OF EARTH SCIENCES, UNIVERSITY OF MINNESOTA, MINNEAPOLIS, MINNESOTA 55455, USA ABSTRACT The Idaho batholith of the North American Cordillera is a large and long-lived silicic intrusive center. We studied fabrics at the regional scale within the different intrusive suites of the Idaho batholith, using microstructural characterization, anisotropy of magnetic susceptibility mea- surements, and shape preferred orientation analyses. Each studied outcrop was collocated with existing U-Pb zircon geochronology and ongoing (U-Th)/He zircon thermochronology results. Three new 40Ar/39Ar biotite ages, collocated with the existing U-Pb zircon ages, constrain the cooling rates within the batholith. The presence of dominantly magmatic microstructures allows us to interpret the results relative to the U-Pb zircon ages and observe spatial and temporal patterns of fabric development. The early (pre–80 Ma) intrusive suites exhibit solid-state microstructures that show a consistent orientation only in the western part of the batholith. Fabrics in the 83–67 Ma Atlanta peraluminous suite are weak and inconsistent in orientation, despite emplacement during regional contraction. We hypothesize that the lack of consistently oriented fabrics in the Atlanta lobe results from either: (1) topographic effects that caused local extensional/neutral strain environments in the upper parts of a crustal plateau; or (2) emplacement in thin, horizontal magmatic sheets. In contrast, fabrics within the 66–53 Ma Bitterroot peraluminous suite are well developed and consistently oriented (NW-striking; NE-dipping), recording localized contraction during magmatism. LITHOSPHERE; v. 9; no. 2; p. 283–298 | Published online 12 October 2016 doi: 10.1130/L551.1 INTRODUCTION this Cordilleran magmatic arc. They evaluated 1989, 1998; Benn, 2010). The preservation of deformation within restricted areas and time magmatic microstructures indicates the mag- Large silicic intrusive complexes are funda- frames defined by mapped plutonic boundar- matic fabrics were “locked in” during a limited mental building blocks of the continental crust. ies. The fabrics, within the framework of known time interval immediately prior to crystallization Understanding these large intrusive centers is regional-scale plate trajectories and average (e.g., Fowler and Paterson, 1997; Yoshinobu et essential to our understanding of the growth and strain rates, were then used to elucidate the ori- al., 1998). By combining microstructural data recycling of continental crust. Many workers entation and magnitude of broad-scale tectonic with U-Pb zircon ages from individual plutons, have evaluated the internal structure of individ- strain. Similarly, Chardon et al. (1999) exam- the regional tectonic activity through time can ual plutons as constituent parts of larger batho- ined fabrics within compositionally and structur- be assessed. liths to understand batholith construction and ally distinct plutons in the Coast plutonic com- The majority of the Idaho batholith lacks the deformation through time (Tobisch et al., 1995; plex (Fig. 1). These syntectonic plutons record typical internal plutonic contacts of other large Borradaile and Henry, 1997; Benn et al., 1998, large-scale transpression and together were used silicic batholiths in the North American Cordil- 2001; Launeau and Cruden, 1998; McNulty to reconstruct the tectonic evolution of shear lera (Fig. 1). Common structures in other mag- et al., 2000; Neves et al., 2003; Mamtani and zones within the broader batholith. Results have matic arcs—mesoscale folds, kilometer-scale Greiling, 2005; Sen and Mamtani, 2006; Zak et shown that the growth and deformation record shear zones, mixing and mingling zones—are al., 2007; Archanjo et al., 2008; DeCelles et al., of batholiths provides magmatic and tectonic largely absent in the Atlanta lobe of the Idaho 2009; Benn, 2010; Mamtani et al., 2013; Cao constraints that contribute to our understanding batholith. Rather, these granites are remarkably et al., 2015; Paterson and Ducea, 2015). This of the growth and recycling of continental crust. uniform in composition and structure, consisting approach of analyzing plutons as discrete, time- Construction of a batholith can be under- primarily of biotite granodiorite and two-mica successive crustal additions provides insight stood by evaluating the growth history of indi- granite/granodiorite. The recent designation of into the broader magmatic and tectonic regime. vidual plutons. Most granitic intrusions record magmatic suites within the batholith required a Tobisch et al. (1995), for example, used the spa- some fabric, and quantitative evaluation of the combination of geochronology and geochem- tial and temporal distribution of magmatic ver- macro scopically indiscernible fabrics helps istry (Gaschnig et al., 2010, 2011). Due to the sus solid-state fabric in the central Sierra Nevada to elucidate the subtle strain recorded during apparent compositional homogeneity and cryp- batholith (Fig. 1) to reconstruct the evolution of magma crystallization (e.g., Bouchez, 1997). tic structure, little attention has been paid to the Magmatic fabrics, in particular, preserve orien- tectonic record preserved within the batholith. tations and magnitudes that result from the final Because of these factors, evaluating the first- *Present address: Department of Environmental, Earth and Atmospheric Sciences, University of Mas- increment of strain at the time of crystallization order growth and deformation history of the sachusetts Lowell, Lowell, Massachusetts 01854, USA (e.g., Marre, 1986; Hutton, 1988; Paterson et al., Idaho batholith requires a different approach LITHOSPHERE© 2016 Geological | Volume Society 9 of| AmericaNumber 2| |For www.gsapubs.org permission to copy, contact [email protected] 283 Downloaded from http://pubs.geoscienceworld.org/gsa/lithosphere/article-pdf/9/2/283/1001569/283.pdf by guest on 24 September 2021 BYERLY ET AL. Coast -125˚ W -115˚ W Coast Plutonic Plutonic complex ABcomplex CANADA CANADA PA PA USA USA CIFI CIFI 45˚ N Accreted Accreted C C Terranes Idaho Terranes Idaho batholith batholith OCEA OCEAN 35˚ N N Sierra Sierra Nevada North Nevada North Batholith America Batholith America EXPLANATION EXPLANATION Limit of Cordilleran Thrust Belt Limit of Accreted Terranes Restored crustal thickness contour Two-mica granite belt (km) Peninsular Peninsular Granitic batholiths Range Range 500 km Batholith 500 km Batholith Figure 1. (A) Four large North American Cordilleran batholiths and their spatial relationship to the Sr 0.706 line, the geochemi- cally defined boundary between accreted terranes and cratonic North America (Armstrong et al., 1977). (B) Map of restored crustal thicknesses (Coney and Harms, 1984) superimposed on Late Cretaceous–Paleogene two-mica granite belt (Miller and Bradfish, 1980) showing the spatial coincidence of overthickened crust and the Idaho batholith. Contours are 10 km. than that applied to the study of other Cordil- constrained the emplacement and crystalliza- Magmatism continued in Idaho with the Challis leran batholiths. tion history and tracked the source and isotopic intrusive suite (51–43 Ma; Gaschnig et al., 2010, We present fabric measurements of samples evolution of the crustal melt. The emplacement 2011), which is not considered to be part of the from dated (U-Pb zircon; Unruh et al., 2008; of the Idaho batholith and the intrusion of the Idaho batholith. Giorgis et al., 2008; Gaschnig et al., 2010, 2013, subsequent Challis suite account for ~32,000 The border zone suites consist of a series 2016; Braudy et al., 2016) field sites to recon- km2 spatial extent at present, representing a 50 of N-S–trending tabular bodies located east of struct the fabric evolution of the Idaho batholith m.y. (98–43 Ma) episode of magmatism. the western Idaho shear zone and suture zone through time. By tying structural measurements Prior to Idaho batholith magmatism, a spa- plutons. Early metaluminous plutons were to geochronologic data, we evaluate the record of tially restricted N-S–trending series of plutons emplaced simultaneously with the border zones deformation preserved within the Idaho batho- forming the suture zone suite of Gaschnig et al. suite, but they are exposed in the Atlanta lobe lith at specific time-space points. This approach (2010) was intruded in western Idaho, straddling of the Idaho batholith as roof pendants and was chosen for the Idaho batholith because it is the boundary between cratonic North America septa within the younger phases and along the not dependent on the a priori ability to map indi- and accreted terranes (Manduca et al., 1992, eastern boundary of the batholith. The Atlanta vidual plutonic boundaries. Fabric orientations 1993; Giorgis et al., 2008; Gaschnig et al., 2010). peraluminous suite is the largest phase of the and magnitudes were measured using shape The suture zone suite was affected by the west- batholith, making up the majority of the Atlanta preferred orientation (SPO) and anisotropy of ern Idaho shear zone, a major transpressional lobe,
Load more

Recommended publications
  • Porphyry and Other Molybdenum Deposits of Idaho and Montana
    Porphyry and Other Molybdenum Deposits of Idaho and Montana Joseph E. Worthington Idaho Geological Survey University of Idaho Technical Report 07-3 Moscow, Idaho ISBN 1-55765-515-4 CONTENTS Introduction ................................................................................................ 1 Molybdenum Vein Deposits ...................................................................... 2 Tertiary Molybdenum Deposits ................................................................. 2 Little Falls—1 ............................................................................. 3 CUMO—2 .................................................................................. 3 Red Mountain Prospect—45 ...................................................... 3 Rocky Bar District—43 .............................................................. 3 West Eight Mile—37 .................................................................. 3 Devil’s Creek Prospect—46 ....................................................... 3 Walton—8 .................................................................................. 4 Ima—3 ........................................................................................ 4 Liver Peak (a.k.a. Goat Creek)—4 ............................................. 4 Bald Butte—5 ............................................................................. 5 Big Ben—6 ................................................................................. 6 Emigrant Gulch—7 ...................................................................
    [Show full text]
  • Characterization of Ecoregions of Idaho
    1 0 . C o l u m b i a P l a t e a u 1 3 . C e n t r a l B a s i n a n d R a n g e Ecoregion 10 is an arid grassland and sagebrush steppe that is surrounded by moister, predominantly forested, mountainous ecoregions. It is Ecoregion 13 is internally-drained and composed of north-trending, fault-block ranges and intervening, drier basins. It is vast and includes parts underlain by thick basalt. In the east, where precipitation is greater, deep loess soils have been extensively cultivated for wheat. of Nevada, Utah, California, and Idaho. In Idaho, sagebrush grassland, saltbush–greasewood, mountain brush, and woodland occur; forests are absent unlike in the cooler, wetter, more rugged Ecoregion 19. Grazing is widespread. Cropland is less common than in Ecoregions 12 and 80. Ecoregions of Idaho The unforested hills and plateaus of the Dissected Loess Uplands ecoregion are cut by the canyons of Ecoregion 10l and are disjunct. 10f Pure grasslands dominate lower elevations. Mountain brush grows on higher, moister sites. Grazing and farming have eliminated The arid Shadscale-Dominated Saline Basins ecoregion is nearly flat, internally-drained, and has light-colored alkaline soils that are Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and America into 15 ecological regions. Level II divides the continent into 52 regions Literature Cited: much of the original plant cover. Nevertheless, Ecoregion 10f is not as suited to farming as Ecoregions 10h and 10j because it has thinner soils.
    [Show full text]
  • Bonner County
    Bonner County, 117o0231 116o4800 48o5645 Idaho Zdt Qm Qm Kgd Kgd Yp Kgdh Kgd Qa Qm Kgd Qm Kgd Qm Yp Yp 0 5 10 miles Qm Kgd Kgd 0 8 16 kilometers Priest Lake Kgd 1:500,000 Kgdh Priest Ri Kgd 116o0251 Kgdh o Yp 95 Yp Qm 48 3000 v Kgd 2 Qm e r Qm D e Kgdh Qm ta Cretaceous Yp c Ts P h Qm r m i e Kaniksu Qm Ts e Kgdh 57 s Kgd Qa n t t Kgdh R Batholith Qm Yp Qm i v e Kgd r Qm Yp Qm Yp Kgdh Qm Yp YXm 200 Yp Qm Qm Yp Kgd Sandpoint Qm Tgdd Hope Qm Yp Qm Yp Qm S Kgdh ite o f IcYra 95 e DYc Tgdd YXm Kgd Kgd amYc an Yra 2 Wm Cla d Qm r p nd O Yag Qa Yp k a Pe reil F th le R rielle o o YXm iv Kog Qa rk f M 41 er Yra Ymiu isYmil Yag d Path Yc Ymil so la Floo ula ou nt Flo iss e Cocolalla Yra Ymiu ods M Yr a Yc m Yp Yp h Kgd Ymiu Priest Rv c Qmf Qmf a Lake PendYp Orielle Core Complex t Yra e Qmf Yc D Yra Kgd v YXm R Ktq Tcr Kgdh Qmf t Yc s Kgdh Cs e i Cs YXm r Qmf 47o5800 P Ymil Cs Ymil Ymiu Yra 47o5330 o 116 3000 Digital Atlas of Idaho, Sept. 2002 http://imnh.isu.edu/digitalatlas Compiled by Reed Lewis, Idaho Geological Survey http://www.idahogeology.org Bonner County The northern and western parts of the Bonner county, west of Sandpoint contain the Priest River metamorphic core complex, containing highly metamorphosed rocks of Proterozoic age.
    [Show full text]
  • Idaho Batholith and Its Southern Extension
    WILLIAM H. TAUBENECK Department of Geology, Oregon State University, Corvallis, Oregon 97331 Idaho Batholith and Its Southern Extension ABSTRACT for 28 mi in the most westerly exposures of the batholith are about S. 20° E. Southeast trends Distribution of minerals and rock types, em- also occur near South Mountain in pre-Tertiary placement structures, and postconsolidation country rocks west of the southernmost expo- history are more complex within the Idaho sures of the batholith. The southeast trends batholith than most published descriptions sug- within and outside the batholith indicate that a gest. Hornblende occurs in some areas many significant change in structural direction occurs miles within the batholith, and planar structure in southwest Idaho in the region near South also is present in some of its interior regions. Mountain. In the vicinity of the Cascade Reservoir in The locations of the south and southeast con- west-central Idaho, field relationships and mo- tacts of the Idaho batholith are uncertain, but dal data for granitic rocks are inconsistent with some inferences regarding the position of the the conclusion (Schmidt, 1964) that the bed- batholith are possible from isolated occurrences rock systematically and gradationally changes of Ordovician sedimentary rocks south of Twin from schist and gneiss to directionless granitic Falls and from exposures of pre-Tertiary sedi- rock along 35-mi traverses west to east across mentary and igneous rocks near the Idaho- the border and interior of the batholith. Nevada state line. Major fault blocks within the Idaho batholith Northward continuity of the Sierra Nevada invalidate the concept (Hamilton and Myers, batholith to the Nevada-Oregon boundary is 1966) of a resistant mass that defied internal well established.
    [Show full text]
  • Age Determinations of Tee Rocks of the Batholiths of Baja Amd Southern
    Ao. AGE DETERMINATIONS OF TEE ROCKS OF THE BATHOLITHS OF BAJA AMD SOUTHERN CALIFORNIA, SIERRA NEVADA, IDAHO, AND THE COAST RANGE OF WASHINGTON, BRITISH COLUMBIA, AND ALASKA* By Eo S, Larsen, Jr., David Gottfried, H. W. Jaffe, and C. L. Waring Augast 1957 Trace Elements Investigations Report 695 GEOLOGIC^ _ '•$.-'- DENVER *U$ This preliminary report is distributed •without editorial and technical review for conformity with official standards and nomenclature. It is not for public inspection or *This report concerns work done on "behalf of the Division of Research of the U« S. Atomic Energy Commission. USGS - TEI-695 GEOLOGY mD MINERALOGY Distribution If6. of copies Division of Ifew Materials, Albuquerque 0 <>*«,»,,«.**.««*»»»»*„*.**» 1 DiTision of Raw Materials, Austin .«...»«»...*»*.<,..«.***»*»...*. 1 Division of Raw Materials, Casper *»»,.*»«*.*. 0 ....„,,..«,......... 1 Division of Raw Materials, Denver ».».«,«»»««*.«.................. 1 Division of Raw Materials, Rapid City ..».„...».......*»....,.,.. 1 Division of Raw Materials, Salt Lake City ... , 0 .. o........ e ...... 1 Division of Raw Materials, Spokane .*.. 0 .*..».»*.*».*•»...*»»**.* 1 Division of Raw Materials, Washington ..,.. ..„,„<>. 0 .............. 5 Division of Research, Washington ......<,„..„*.„.„.,.<>,........... 1 Exploration Division, Grand Junction Operations Office .......... 1 Grand Junction Operations Office ......o......... a............... 1 Technical Information Service Extension, Oak Ridge 88 »........... 6 U» S» Geological Survey? Foreign Geology Branch,
    [Show full text]
  • Belt Orogenesis Along the Northern Margin of the Idaho Batholith
    BELT OROGENESIS ALONG THE NORTHERN MARGIN OF TI-IE IDAHO BATI-IOLITI-I Charles S. Hutchison IBMG Open-File Report 81-2 Idaho Bureau of Mines and Geology This report is preliminary Department of Lands and may be modified later. Moscow, Idaho 83843 April 1981 TABLE OF CONTENTS Page ABSTRACT 1 INTRODUCTION 2 METASEDIMENTARY FORMATIONS 7 Burke Formation 7 Revett Formation 12 St. Regis Formation 13 Wallace Formation 16 Wallace Lower Gneiss . 16 Wallace Lower Schist 20 Wallace ·Upper Gneiss 20 INTRUSIVE ROCKS . 22 Foliated Amphibolite Sheets (Purcell Sills?) 22 Idaho Batholith Granitoids 23 Pegmatites .. • 27 Diabase Sills 28 Porphyritic Rhyodacite Sills . 30 Orthogneiss 31 GEOCHEMI STRY 32 SUMMARY OF THE GEOCHRONOLOGY 37 Belt Sedimentation 37 Belt Metamorphism 39 Idaho Batholith and Related Rocks 40 STRUCTURE . 41 OROGENIC EVOLUTION 45 ACKNOWLEDGMENTS 50 REFERENCES SO iii LIST OF TABLES Page Table 1. Chemical analyses and Barth mesonorms of metamorphic rocks 33 Table 2. Chemical analyses and Barth mesonorms of amphibolite and pegmatite . 34 Table 3. Chemical analyses and Barth mesonorms of diabase sill rocks 35 Table 4. Chemical analyses and Barth mesonorms of granitoid rocks . 36 LIST OF FIGURES Figure 1. Principal tectonic elements of the Belt aulacogen 4 Figure 2. Simplified geological map showing the distribution of Beltian metamorphic grades in relation to the Idaho batholith . 6 Figure 3. Geologic map of the study area in the Clearwater National Forest, Idaho . 8-9 Figure 4. Thin-section appearance 10-11 Figure 5. Hand-specimen appearance 14-15 Figure 6. Details of outcrops 18-19 Figure 7. Details of outcrops 21 Figure 8.
    [Show full text]
  • SAWTOOTH, IDAHO F O
    STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS OHIO GEOL06ICM. iUKVtl C/5 C 85' *>j SAWTOOTH, IDAHO f O \ SURVEY BULLETIN 1319-D Mineral Resources of the Sawtooth i Primitive Area, Idaho By THOR H. KILLSGAARD and VAL L. FREEMAN, U.S. GEOLOGICAL SURVEY and by JOSEPH S. COFFMAN, U.S. BUREAU OF MINES STUDIES RELATED TO WILDERNESS-PRIMITIVE AREAS GEOLOGICAL SURVEY BULLETIN 1319-D An evaluation of the mineral potential of the area -tTNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1970 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HICKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. 79-607357 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, B.C. 20402 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS In accordance with the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Conference Report on Senate bill 4, 88th Congress, the U.S. Geological Survey and the U.S. Bureau of Mines are making mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe," when the act was passed were incor­ porated into the National Wilderness Preservation Sys­ tem. Areas classed as "primitive" were not included in the Wilderness System, but the act provides that each primitive area be studied for its suitability for incor­ poration into the Wilderness System. The mineral sur­ veys constitute one aspect of the suitability studies. This bulletin reports the results of a mineral survey in the Sawtooth Primitive Area and vicinity, Idaho. The area discussed in the report includes the primitive area, as defined, and some bordering areas that may come under discussion when the area is considered for wilderness status.
    [Show full text]
  • Synplutonic Dikes of the Idaho Batholith Idaho and Western Montana and Their Relationship to the Generation of the Batholith
    University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 1986 Synplutonic dikes of the Idaho batholith Idaho and western Montana and their relationship to the generation of the batholith David Allen Foster The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Foster, David Allen, "Synplutonic dikes of the Idaho batholith Idaho and western Montana and their relationship to the generation of the batholith" (1986). Graduate Student Theses, Dissertations, & Professional Papers. 7531. https://scholarworks.umt.edu/etd/7531 This Thesis is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. COPYRIGHT ACT OF 1976 This is an unpublished manuscript in which copyright sub­ s is ts . Any further reprinting of its contents must be approved BY THE a u t h o r . MANSFIELD L ibrary Un iv e r s it y of Montana Date : 1 9 8 A Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SYNPLUTONIC DIKES OF THE IDAHO BATHOLITH, IDAHO AND WESTERN MONTANA, AND THEIR RELATIONSHIP TO THE GENERATION OF THE BATHOLITH By David Allen Foster B.A., SUNY Potsdam Presented in partial fulfillment of the requirements for the degree of Master's of Science University of Montana 1986 Approved by Chairman, Board of Examiners Dean, Graduate School /Ù.
    [Show full text]
  • Petrology of the Alaskites of the Boulder Batholith, Montana Kenneth C
    University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 1977 Petrology of the alaskites of the Boulder batholith, Montana Kenneth C. Malick University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Malick, Kenneth C., "Petrology of the alaskites of the Boulder batholith, Montana" (1977). Theses and Dissertations. 189. https://commons.und.edu/theses/189 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. PETROLOGY OF THE ALA.SKITES OF THE BOULDER BA.THOLITH, MONTAN.A. by Kenneth c. Malick Bachelor of Arts, Millersville State College, 1973 A Thesis Submitted to the Graduate Faoult:, of the University of North Dakota 1n partial fulfillment of the requirements for the degree of Master of Soience Grand Forks, North Dakota Ma:, 1977 This t'1e;;is ::;ubmitte::3 ~;y i:(o:m(Jth c. :falick in partial ful­ filln:ent of the r~quj rements f0::- th3 :J,~gree of ;.'a $ter of Science fro::. the Univer:;ity of North Dako+,::i. is her,lby approved by tha Faculty Advisory Cor1L-ni ttf38 und-Jr whom thH ~vorlc h3.s been done, ~~'~ ue:1_~~)-i)__ ---~ Dean of the Graiuate School Permission T1Ue PETROLOOY OF THE AWKITES OF THE BOULDER BA.THOLITH. MONTANA. Department ____________Ge:.;:.::o_l_oQgY._ ______________________________________ Degree ---------------~Ma__ st~e_r;:....;:o_f~S~ci~e.n~c~e=----------------------------- In presenting this thesis in partial fulf'illm.ent of the requirement for a graduate degree from the University of North Dakota, I agree that the Library of this University shall make it freely available for inspection.
    [Show full text]
  • Idaho Batholith Near Pierce and Bungalow Clearwater County, Idaho
    Idaho Batholith Near Pierce and Bungalow Clearwater County, Idaho GEOLOGICAL SURVEY PROFESSIONAL PAPER 344-D Idaho Batholith Near Pierce and Bungalow Clearwater County, Idaho By ANNA HIETANEN METAMORPHIC AND IGNEOUS ROCKS ALONG THE NORTHWEST BORDER ZONE OF THE IDAHO BATHOI~ITH GEOLOGICAL SURVEY PROFESSIONAL PAPER 344-D Petrologic study of igneous rocks in the northwestern corner of the Idaho batholith UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 CONTENTS Page Plutonic rocks-Continued Abstract __________________________________________ _ D1 Petrographic description-Continued Page Introduction ______________________________________ _ 1 Quartz monzonite and related rocks ___ -------- D14 Locality and specimen numbers _________________ _ 2 Stock at Beaver Creek _________________ _ 14 Major geologic units _______________________________ _ 2 Coarse-grained quartz monzonite and mon- Anorthosite, its country rocks, and the Orofino series of zotonalite ___________________________ _ 20 Anderson (1930)---------------------------------- 4 Granite ___________________________________ _ 23 Belt series ________________________________________ _ 4 Pegmatites ______ -- _____ ---_-- -------------- 25 Distribution ___________________________________ _ 4 Plagioclase pegmatite __________ --_------ 25 Lithology and correlation _______________________
    [Show full text]
  • Gem County, Idaho
    Gem County, Idaho Kog o Tcr 44 3000 Kog Kog Kog KtqKtg Qs TcrTcr Qs Qs KtqKtg Qa 43o1000 Qa Tcr Crk 0 5 10 miles Tcr 0 8 16 kilometers Qa Tps Squaw QTs Ktq QTs Ktg Tcr Qm Tcr Qa Qm Tps Sweet Tcr Qa Qs Qm Tps Qs Ts PayetteQs Black CanyonQTs Qs 52 Ts Dam Qs 52 Qa R. Tgdd Emmett Kgd Qs Tcr Tgdd Tps Qa Ts Tcr o 16 Qm 43 5000 Tgdd Kgd 116o4000 Tps 116o2000 Digital Atlas of Idaho, Nov. 2002 http://imnh.isu.edu/digitalatlas Compiled by Paul K. Link, Idaho State University, Geosciences Dept. http://www.isu.edu/departments/geology/ Gem County Gem County covers a small area on the northern border of the Snake River Plain, including the drainage of Squaw Creek and the main channel of the Payette Rvier. On the southwest are outcrops of Miocene to Recent lake and fluvial beds in bluffs above the Payette River. Much of the northern panhandle of the county is underlain by Miocene (17 Ma) Columbia River basalt. North-trending fault zones parallel Squaw Creek and control the linear topography of the northern county. On the eastern edge of the county are several outcrops of Cretaceous tonalite, orthogneiss and granodiorite of the Idaho batholith complex. Cenozoic Geologic History of Gem and Payette Counties The Cenozoic geologic history of Gem and Payette Counties is similar to many areas in southwestern Idaho. Volcanism resulted mainly from the faulting and initiation of the Western Snake River Plain in the Miocene. Miocene sedimentation occurred within the many lakes interconnected at times by a river system that was present in the newly formed rift environment.
    [Show full text]
  • Spangle Lakes: an Investigation of Late Archaic Human Land
    SPANGLE LAKES: AN INVESTIGATION OF LATE ARCHAIC HUMAN LAND- USE WITHIN THE SAWTOOTH MOUNTAINS by Kaitlyn Mansfield A thesis submitted in partial fulfillment of the requirements for the degree of Master of Arts in Anthropology Boise State University May 2017 2017 Kaitlyn Mansfield ALL RIGHTS RESERVED BOISE STATE UNIVERSITY GRADUATE COLLEGE DEFENSE COMMITTEE AND FINAL READING APPROVALS of the thesis submitted by Kaitlyn Mansfield Thesis Title: Spangle Lakes: An Investigation of Late Archaic Human Land-Use Within the Sawtooth Mountains Date of Final Oral Examination: 03 March 2017 The following individuals read and discussed the thesis submitted by student Kaitlyn Mansfield, and they evaluated her presentation and response to questions during the final oral examination. They found that the student passed the final oral examination. Pei-lin Yu, Ph.D. Chair, Supervisory Committee Mark G. Plew, Ph.D. Member, Supervisory Committee Samantha H. Blatt, Ph.D. Member, Supervisory Committee The final reading approval of the thesis was granted by Pei-lin Yu, Ph.D., Chair of the Supervisory Committee. The thesis was approved by the Graduate College. ACKNOWLEDGMENTS I wish to give a special thanks to my committee chair, Dr. Pei-lin Yu, and members, Dr. Mark Plew and Dr. Samantha Blatt who provided me leadership and guidance. I would also like to thank my family and friends for encouraging and supporting me now, and throughout the future, in my education. iv ABSTRACT Recent high altitude archaeological research has provided evidence for seasonal utilization of high mountain landscapes during the Late Archaic era. Sites in the Western United States display varying patterns of land use suggesting that during the Late Archaic, mountain landscapes were used differently based upon unique environmental conditions.
    [Show full text]