Middle Cambrian Stratigraphy of the House, Wah Wah, and Adjacent Ranges in Western Utah

LEHI F. HINTZE Department of Geology, Brigham Young University, Provo, Utah 84602 RICHARD A. ROBISON Department of Geology, University of Kansas, Lawrence, Kansas 66045

ABSTRACT formations in the range. Since 1955, map- of the House Range is shown in Figure 2. ping has been conducted under Hintze's di- For the most part, Walcott's original for- Geologic mapping and paléontologie rection in several ranges in western Utah mational units are readily mappable entities evaluation of Middle Cambrian strata in (Stokes, 1962; Hintze, 1963). Maps of five that can be recognized in the House Range western Utah have extended the usage of 15' quadrangles (Fig. 1) have been pub- and adjacent ranges. several formations first defined in the lished (Hintze, 1974b, 1974c, 1974d, House Range by Walcott and have shown 1974e, 1974f). Field mapping of two addi- Prospect Mountain Quartzite that new units are needed outside of the tional quadrangles, Sand Pass and Fish House Range for upper Middle Cambrian Springs, was also completed in 1974. The Hague (1883, p. 254) named the Pros- strata of different facies. The following mapping has shown that all Middle Cam- pect Mountain Quartzite in the Eureka dis- usage is proposed for the House Range: brian formations in the House Range, ex- trict of central Nevada, and Walcott Lower Cambrian — Prospect Mountain cept the Marjum and Weeks Formations, (1908a, p. 12) first applied the name in the Quartzite and the lower member of the can be satisfactorily mapped in adjacent House Range, 200 km east of the type area. Pioche Formation; Middle Cambrian — ranges. In this paper we discuss Middle The name has subsequently been widely Tatow Member of the Pioche Formation, Cambrian formations mapped in the House used in western Utah and Nevada for the Millard Member and upper members of the Range, define new mappable rock units in predominantly quartzitic rocks at the base Howell Limestone, Chisholm Formation, the upper part of the Middle Cambrian of the Cambrian unit. Misch and Hazzard Dome Limestone, Whirlwind Formation, rocks of adjacent ranges, and correlate (1962, p. 304) recommended restriction of Swasey Limestone, Wheeler Shale, Marjum Middle Cambrian nomenclature in western the name to exclude various Precambrian Formation, and the lower part of the Weeks Utah and eastern Nevada. units that had been included within the Limestone. formation by others. Stewart (1970) rec- New formations defined in the Wah Wah CENTRAL HOUSE RANGE ommended that rocks formerly called Pros- Mountains include the Eye of Needle STRATIGRAPHIC TERMINOLOGY pect Mountain Quartzite in the southern Limestone (Wheeler Shale equivalent), Pier- Great Basin of California and Nevada be son Cove Formation (lower Marjum For- Stratigraphie terminology for Lower and subdivided into other units. Woodward mation equivalent), and the Wah Wah Middle Cambrian rocks in the central part (1968) and Crittenden and others (1971) Summit Formation (Weeks Limestone near followed Misch and Hazzard (1962) in equivalent). The Trippe Limestone is ex- limiting Prospect Mountain to pink, tan, tended from the Deep Creek Range into and brown quartzites of probable Early west-central Utah, and a new member, Fish Cambrian age. It is overlain by the Pioche Springs Member, is defined as a thin but Shale and underlain in Utah by the Mutual widely mappable unit. Formation and in eastern Nevada by the The House Range contains the most con- Stella Lake Quartzite and other Precam- tinuously fossiliferous trilobite sequence, brian formations. but most ranges in western Utah contain 2 Continuation of Walcott's designation of r-. -|8 the following faunas: Albertella, Glos- KEY Prospect Mountain for basal Cambrian sopleura, Ehmaniella, Ptychagnostus gib- quartzite in the House Range conforms to 3«: v7 1. Pioche, Nevada bus, Bathyuriscus fimbriatus, and Eldo- currently accepted usage. The base of the 6 2. Deep Creek Range radia. Key words: stratigraphie nomen- 3. Fish Springs Range and formation is not exposed in the House clature, trilobite faunas, carbonate rocks. t northern House Range Range; the partial thickness measured in •J5 4. Central House Range the range by various authors is shown in INTRODUCTION 5. Wah Wah Mountains - Figure 2. A section of 670 m, measured on southern House Range the west face of the House Range about 22 Walcott (1908a, 1908b) first described 6. Cricket Range km north of Marjum Canyon, is believed to the exceptionally fossiliferous Middle and 7. Drum Mountains be the maximum exposed thickness of the 8. Dugway Range Upper Cambrian strata of the House Range formation in the range. The 670+-m thick- 9. East Tintic Mountains of western Utah. Deiss (1938), Wheeler ness is within the limits of the nearest complete sections in adjacent ranges, as indi- (1948), and Robison (1960) recommended Figure 1. Map showing location of Cambrian changes in House Range stratigraphie strata discussed in text. Black areas are Cam- cated in Table 1. nomenclature, and Powell (1959) and brian outcrops. Dashed lines outline quadrangles A detailed description of only the upper- Hanks (1962) published the first geologic where stratigraphic units discussed in text have most 40 m of the formation in the House maps showing the distribution of Cambrian been mapped. Range has been published (Deiss, 1938, p.

Geological Society of America Bulletin, v. 86, p. 881-891, 5 figs., July 1975, Doc. no. 50701.

881

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1139-1140). The 630 m of beds exposed show small-scale cross-bedding. The Pros- are intercalated. Most of Merriam's (1964) below this succession are less varied and pect Mountain Quartzite generally is in comments on lithology and bedding fea- consist of medium- to coarse-grained beds 30 to 60 cm thick; some beds are as tures of the Prospect Mountain Quartzite at pinkish-gray to light brown-gray quartzite much as 2 m thick. A few phyllitic silty Pioche apply equally well in the House and quartzitic sandstone that weather to sandstone beds less than 1 m thick, which Range. Fossils have not been found in the shades of reddish brown and commonly weather greenish gray and are micaceous, formation in the House Range.

Pioche Formation (Revised) Robison Walcott Deiss Wheeler Hanks This paper 1938 1948 i960 1962 1908b Walcott (1908a, p. 11-12) named the Weeks Weeks "Weeks" Weeks Weeks Weeks Pioche Formation, designated a type local- limestone limestone limestone formation Limestone Limestone ity near Pioche, Nevada, and identified the 424 m 1,390' 591 m 1,940' 423 m 1,388' 366 m 1,200' formation as part of the Cambrian se- Marjum Marjum "Marjum" Marjum Marjum Marjum quence in the House Range. Merriam limestone limestone limestone formation Limestone Formation (1964) and A. R. Palmer (in Merriam, 415" 1,362- 1964) have most recently evaluated the 336m 1,102' 466 m 1,530' 466 m 1,530' 431m 1,413' lithologic and paleontologic characteristics Wheeler Wheeler Wheeler Wheeler Wheeler Wheeler of this formation in the Pioche district. shales shale shale shale Formation 128- Shale 4]9. 174 m 570' 107 m 350' 175 m 574' 149 m 490' The Pioche Formation in the Pioche district and the combined Pioche and Tatow Swasey Swasey Swasey V incompletely limestone — c member c member ?f member quency of limestone units increases toward "5 & « s 112m 369' 116 m 380' described) j TÓ > ft the top of the formation. Thus, the 0 J) 0 « Millard 1 E Millard JI Millard 1 E Millard sedimentary sequence is basically the same Member Member limestone member in the two areas, but detrital rocks in the 133 m 435' 255 m 835' 97 m 317' 94 m 310' House Range section have a larger average Spence shale c Tatow Busby Tatow Tatow o Tatow grain size because they are nearer to the 6 m 20' limestone quartzite formation Limestone o Member source area. Paleontologically, the type Langston (?) E limestone o Pioche contains late Early Cambrian olenel- 50 m 165' 53 m 175' 55 m 180' 62 m '205' Li- lid faunas in the lower part of the forma- lower tion, and the uppermost beds contain an Pioche Pioche Pioche Pioche Pioche ai shale shale shale formation Shale -C member early Middle Cambrian Albertella Zone u 38 m 125' 81 m 265' 75 m 246' o 128 m 420' £ fauna with Albertella cf. A. proveedora Prospect Prospect Prospect Prospect Prospect Prospect Lochman and Mexicella sp. (A. R. Palmer, Mountain Mountain Mountain Mountain Mountain Mountain in Merriam, 1964, p. 25-27). The Pioche of sandstones quartzite quartzite quartzite Quartzite Quartzite the House Range contains a late Early 419m+ 1,375'+ 305 m+ 1,000'+ 12 m+ 40'+ 670m + 2,200'+ Cambrian Bonnia-Olenellus fauna (Robi- son and Hintze, 1972) and the upper beds Figure 2. Comparison of stratigraphic terminology used for Lower and Middle Cambrian rocks in of the Tatow contain an early Middle House Range, Utah. Thickness of units shown in feet, as originally published, and also in meters. Cambrian Albertella Zone fauna with Wheeler and Robison did not present new measurements. Walcott's "Spence shale" is probably a Albertella cf. A. proveedora, Mexicella sp., downfaulted part of the Chisholm Formation. The "Weeks limestone" of Deiss probably includes and other trilobites (undescribed collections some of overlying Orr Formation. identified by Robison). Therefore, to em- phasize these close similarities and to better TABLE 1. PROSPECT MOUNTAIN QUARTZITE THICKNESS ADJACENT TO THE HOUSE RANGE portray regional stratigraphic relations, we propose that the Tatow in west-central Utah be reduced to member rank, and that Thickness of Location Distance and direction References it be included as the upper member of a Prospect Mountain from central Quartzite House Range revised bipartite Pioche Formation. We also propose that the Pioche as formerly (m) (ft) (km) identified in the House Range be redesig- nated as an unnamed lower member of the 910 3. ,000 So. Snake Range 100 SW. Misch and Hazzard, 1962 890 2. ,950 Deep Creek Range 80 NW. Bick, 1966 revised formation. Because of heterogene- 1,740 5,,70 0 Dugway Range 80 N. Crittenden and others, 1971 ous composition, the name Pioche Forma- 760 2, ,500 Sheeprock Mts. 100 NE. Crittenden and others, 1971 tion rather than Pioche Shale is more ap- 1,050 3. ,450 Canyon Range 100 E. Crittenden and others, 1971 propriate at all localities in eastern Nevada 1,200 4, ,000 Beaver Mts. 80 SE. Woodward, 1968 and west-central Utah.

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-1- -2- -3- -4- -5- -6- -7- -8- -9- Trilobite zones Zone Deep Creek Fish Springs and Central Wah Wah and Cricket Ronge Drum Mountains Dugway Range East Tintic Mts. and founas Sym- Pioche, Nevada Range northern House Range southern (Crittenden ond (Staatz and (Morris and bol in western Utah (Nolan, 1935) House Ranges House Ranges others, 1961) Corr, 1964) Levering, 1961) (Merriam, 1964) C Limestone P Straight Canyon ç Mendha _ Hicks 0rr C Orr 0rr 0rr c cw Formation Formation c Formation C Formation ** Formation Formation C Formation Limestone O Opex | Crepicephalus | Unit 13 White mark- White mark- Formation c er member er member F m and F m Dolomite N Unit 12 Ì c Cedaria Zones c Û. Lamb Lomb c Lamb D Unit 11 Weeks Limestone M ledgy ledgy Summi t undivided Summi t Unit 10 Dolomite Dolomite c Dolomite L Dolomite Limestone member member Wa h Wa h c Dolomite K

Wo h Cole Wa h ! | |

Lejopyge calva " | L / Unit 9 El Fish L Fish Springs Fish Springs Subzone-— c Limestone J Canyon yEldoradia Springs /EI El El £1 Member Member — fauna Trippe El Member L El El El Dolomite Limeston e Limestone Bc Limeston e Limeston e lower lower lower Bolaspidella 1 o member member E Bc member contrada Bc Unit 8

Tripp e Marjum

Tripp e Fandangle Tripp e o | [ Subzone u. Be o V Young Limestone 1 Q) s Zon e Q. Limestone Z Peak Pierson Be Formation Pierson Pierson Y Unit 7 0 S. Dolomite Bluebird .c Cove Bf Cove Dolomite 01 Meadow Bf C°Ve Bf Bathyuriscus if Valley Bf Formation Formation ^ Herkimer

Bolaspidella Formotion Member ßmbriatus Limestone Bf Bf Condor Subzone gf Dolomite H Dog mar Member Bf Dolomite Bf Bf Bf Bf Step Wheeler Bf Wheeler Eye of Needle Eye of Needle Bf Ptychagnostus Shale Limestone Limestone B Trailer Teutonic P Ridge Shole Limestone G gib bus fauna ^ Abercrombie P P P Limestone Limestone Glyphaspis Member Gy Swasey Gy Swasey Swasey Swasey GP y Gy Gy Limestone F Gy?

Zon e Limestone fauna Gy Limestone Limestone Limestone Burnt Canyon E Whirlwind E Whirlwind E Whirlwind E Whirlwind E Shole 5 E E Ehmaniella E Member Formation Formation Formation Formation

BothyuTiscus- E fauna Burrows E Dome _ Dome Dome Dome Elrathina Limestone Limestone Limestone E Member Limestone £ Limestone Ophir 1 Formation Peasley £ Peasley Q Shale 4 u Member Chisholm ^ Chisholm Limestone Chisholm Shadscale Limestone D Formation Glossopleura Chisholm Formation Formation Chisholm Formation G G Shale G G G G Formotion G Shale 3 Zone G G Lyndon Howell Howell Howell Howell Formation Limestone C Limestone Limestone Limestone ® Limestone » A

Albertella | | | A A A A 1 A Shale 2 and unnamed A Tatow Tatow Tatow Tatow Limestone B pre-Albertella A Shale 1 Tintic zones undivided A Pioche Member Member Member Member

Middl e Dolomite A I Formatio n Formatio n Formotio n Bu b Formatio n Busby Q Shole O Busby Quartzite Of nQuartziti. *.e lower 0 lower lower Q lower Quartzite Quartzite

Pioch e member member member member Cabin Shale

| 0 ® Cabin Shale Cabin Shale Bonnia-Olenellus Pioch e Pioch e Pioch e | | I Zone 0 Prospect Prospect Prospect Prospect Prospect Prospect Prospect Prospect Mountain Mountain Mountain Mountoin Mountain Mountain Mountoin Mountain Quartzite Quartzite Quartzite Quartzite Quartzite Quartzite Quartzite Quartzite CAMBRIA N Lowe r 1 1 Figure 3. Correlation table for Cambrian units in western Utah and eastern Nevada. Boldface symbols show locations of fossil collections as now known from published sources and from localities collected by Robison. Thickness of rock units not shown to scale.

Lower Member of Pioche Formation. Wah Wah and Drum Mountains. A trilo- The lower Pioche contains siltstone beds Partial stratigraphic sections of this unit, bite fauna typical of the late Early Cam- several meters thick which are less resistant measured near Marjum Canyon in the brian Bonnia-Olenellus Zone has been de- to erosion than the Prospect Mountain. A House Range, are described by Deiss (1938, scribed from about 100 m above the base of change in slope and in color mark the for- p. 1139) and Hanks (1962, p. 120). The the member in the House Range (Robison mational boundary. These lower Pioche member is exposed for nearly 30 km along and Hintze, 1972), and in the Drum Moun- siltstone beds correlate with the Cabin the west face of the range from Marjum tains a fragmentary olenellid cephalon has Shale as mapped by Nolan (1935) in the Canyon northward, and thickness is con- been found in the member by M. B. Deep Creek Range and by Crittenden and stant at 128 m. The strata are mostly McCollum. others (1961) in the Drum Mountains dark-brown phyllitic quartzite and inter- The boundary between the lower (Fig. 3). bedded green shale or siltstone. The quartz- member of the Pioche Formation and the Tatow Member of Pioche Formation. ite is mainly fine to medium grained, is Prospect Mountain Quartzite is placed at Deiss (1938, p. 1143-1144) defined the thick to medium bedded in the lower part the first appearance of substantial beds of Tatow "Limestone" and designated a type of the member, and becomes medium to siltstone in the section. The Prospect Moun- section at Marjum Canyon in the House thin bedded in the upper part. Similar strata tain is clean and uniform quartzite contain- Range. Wheeler (1948, p. 29) assigned the are found in the Cricket Range and the ing a few siltstone beds less than 1 m thick. type Tatow to the Busby Quartzite, a unit

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that Nolan (1935) named in the Deep House Range probably is located near the where it bends westward" is in a place Creek Range (Fig. 3). We reduce the unit to contact between the two members of the where the Tatow Member (Walcott's member rank and propose that the original Pioche Formation. However, exact position "Langston") is in fault contact with the type section be retained. In his description of the series boundary cannot be estab- Chisholm Formation, and Walcott's of the type section, Deiss (1938, p. lished with available faunal evidence. "Spence shale" is likely downfaulted 1138-1139) pointed out that less than half Chisholm Formation. of the strata are limestone, a fact reinforced Howell Limestone As restricted in the House Range (Robi- by Hanks (1962, p. 120-121). Hintze's ob- son, 1960, p. 49-51), the Howell Lime- servation is that no more than 6 of 55 m is Walcott (1908a, p. 11) designated How- stone forms massive cliffs, the lower part limestone and that the rest is chiefly ell Peak, "about 5 miles west of Antelope (Millard Member) of which is dark gray quartzite with interbeds of phyllitic shale. Springs, House Range, Utah," as the type and the upper part (unnamed member) light The Tatow includes the lowest appearance locality for the Howell Limestone. Unfor- gray. of carbonate rock in the House Range and tunately, the location of Howell Peak can Millard Member of Howell Limestone. constitutes an easily recognizable and no longer be ascertained. Walcott's (1908b, Wheeler (1948, p. 35) defined the Millard mappable unit. The lower boundary is p. 182-183) description of lithologic units Limestone in the House Range by elevating placed at the base of the lowest limestone and fossils from the Howell incompletely the basal 86 m of Howell Limestone de- bed, and the upper boundary is placed describes this interval between the better scribed by Deiss (1938) in Marjum Canyon where slope-forming calcareous sandstone identified Pioche and Dome Formations. to formational rank. Robison (1960, p. 50) is overlain by massive cliff-forming lime- His photograph (1908b, PI. 16) of the for- recommended reducing the Millard to stone of the Millard Member of the Howell mations on the north side of Dome (now member status in the House Range, and we Limestone. Death) Canyon clearly indicates that he in- concur with his recommendation. The Mil- Insoluble residues from samples of the cluded the present Chisholm Formation lard Member composes the lower, dark- Tatow Member range from 3 to 97 percent within his Howell Limestone. Deiss (1938, gray weathering part of the cliff-forming and average 59 percent (Table 2). Quartz p. 1144) emended the definition of the Howell Limestone. It is an easily distin- detritus constitutes more than 90 percent of Howell Limestone and presented his guishable map unit within the House and the residue in all but a few samples that are stratigraphic section measured at Marjum Cricket Ranges and the Wah Wah Moun- high in clay. Pyroxene and mica compose Canyon as representative of the formation. tains but is less readily separated from the less than 5 percent of some residues. Wheeler (1948; Wheeler and Steele, 1951) upper Howell Limestone as a map unit in A well-preserved but mostly undescribed temporarily suppressed usage of Howell the Drum Mountains and the Dugway Albertella Zone fauna can usually be found Limestone in House Range terminology by Range. It is probably not surely distin- in the uppermost 10 m of the Tatow inappropriate introduction of terms from guishable elsewhere. Member. Fragmentary ptychoparioid trilo- Pioche, Nevada. Robison (1960) re- Noncarbonate residues (Table 2) de- bites have been collected from 21m above established Howell Limestone in the re- crease abruptly from an average of 59 per- the base of the Tatow on the north side of stricted usage of this paper. cent in the Tatow Member to an average of Marjum Canyon, but generic identity cur- Walcott's (1908b) placement of "Spence 4.5 percent in the Millard Member. Fine- rently is undetermined. With olenellid shale" below the Howell Limestone is in grained detrital quartz and very small trilobites known from the middle of the error (Deiss, 1938, p. 1140). In the House quartz crystals compose most of the insolu- lower member of the Pioche Formation, the Range, Walcott's "Spence shale — on the ble fraction, with clay minerals and traces Lower-Middle Cambrian boundary in the east side of Dome Canyon a little above of mica and ferromagnesian minerals mak- ing up the rest. TABLE 2. INSOLUBLE RESIDUE IN MIDDLE CAMBRIAN Oncolites of probable Girvanella origin FORMATIONS IN MARJUM CANYON AREA, HOUSE RANGE, UTAH are abundant in the Millard Member. Comminuted skeletal debris also may be common, but identifiable invertebrate fos- Formation No. of Approximate Insoluble residue samples sample interval (avg. of all sampled, in %) sils are rare. Deiss (1938, p. 1138) reported (m) Zacanthoides at 31 m above the base of the member. Robison has obtained three Weeks 75 4 21.3 faunules from the member in the vicinity of Marjum Canyon, and all are associated Marjum 108 3 20.9 with large oncolites in dark limestone. The Wheeler 17 6 44.6 lowest collection is from a detached block found about 30 m above the base of the Swasey 24 3 1.8 member, and it contains two fragmentary cranidia of Ptarmiganoides. A second col- Whirlwind 19 2 26.0 lection came from about 60 m above the Dome 32 3 1.8 base and about 200 m south of the mouth of Marjum Canyon along the west face of Chisholm 31 2 3.7 the range. It contains Ptarmiganoides n. Upper Howell 42 3 3.8 sp.; Zacanthoides? sp.; trilobite, n. gen. and sp. (cf. Caborcella); Indiana? sp. (os- Millard Member of Howell 28 2 4.5 tracode); Coreospira walcotti Knight (gas- Tatow Member of Pioche 17 3 59.3 tropod); and Gogia sp. (eocrinoid). A third collection is from a detached block, also from about 60 m above the base, but from the south side of Marjum Canyon. It con- Note: Samples were digested in hydrochloric acid. Noncalcareous shales in the Tatow Member and in the Wheeler, Whirlwind, and Chisholm Formations were not sampled. tains Glossopleura sp.; Zacanthoides? sp.; trilobite, n. gen. and sp. (cf. Achlysopsis);

and Scenella sp. (monoplacophoran). Pre- mappable unit in the House Range, where it Dome, but 18 m above the base the follow- viously, Ptarmiganoides and Coreospira forms a dark ledge- and slope-forming unit ing trilobites have been collected and walcotti have been reported only from the between the massive light cliffs of the Dome identified by Oldroyd (1973, p. 28, 29): Albertella Zone, whereas the first appear- and upper Howell Limestones. As mapped Ehmaniella n. sp., Kootenia aff. K. dawsoni ance of Glossopleura has been used to mark in the House Range (Hintze, 1974b), the (Walcott), Mexicella n. sp., Poliella n. sp., the base of the Glossopleura Zone. Chisholm Formation consists of three main and Spencella buttsi (Resser). Current bio- Whether the ranges of Ptarmiganoides and parts: the lowest 20 m is a slope-forming, stratigraphic nomenclature of the Middle Glossopleura overlap is now uncertain, but thin-bedded limestone with interbedded Cambrian in the Great Basin is inadequate the base of the Glossopleura Zone appears shale and siltstone; the middle 45 m is a to express lateral biofacies relations, but to fall at least as low as the upper one-third ledge- and low cliff-forming limestone, pending published revision, Oldroyd's of the Millard Member in the House Range. pisolitic in its lower half and bearing abun- faunule is assigned to the lower Bathy- Glossopleura also has been collected by dant Glossopleura in its upper ledges; the uriscus-Elrathina Zone. Robison from the uppermost bed of the top 15 m is a slope-forming, olive- Millard on the east side of Headlight Can- weathering shale. Samples of limestone Whirlwind Formation yon in the Cricket Range. beds (shales were not sampled) averaged Upper Member of Howell Limestone. only 3.7 percent residue (Table 2), which is Wheeler (1948) first suggested that the Although Wheeler (1948) introduced the largely clay rather than quartz, as in re- shaly slope-forming lower part of the term "Burrows limestone" for this interval sidues from formations below the Swasey Limestone be given a separate name in the House Range, its application there is Chisholm. (Fig. 2). Robison (1960) argued that the incorrect. Robison (1960) pointed out that The Glossopleura Zone has one of the term "Condor" from the Pioche area was the Burrows, in its type area near Pioche, most widespread faunas of the eastern inappropriate for this interval in the House Nevada, occurs above the Chisholm For- Great Basin (Fig. 3), and it is particularly Range and proposed the name Whirlwind mation rather than beneath it (Fig. 3). well represented in the Chisholm Forma- Formation, at the same time restricting Robison (1960, p. 50) emended the tion of the House Range. Oldroyd (1973) Swasey to the cliff-forming limestone definition of Howell Limestone by remov- has documented a succession of faunules above. As thus defined, the Whirlwind ing the Chisholm part, as shown in Figure with 13 genera and 25 species of trilobites Formation is an easily mappable slope- 2. As thus restricted, the Howell Limestone from the Chisholm of the House Range and forming unit lying between two cliff- forms massive cliffs with a light-weathering Drum Mountains. Glossopleura, Alokisto- forming massive limestone formations. A upper member and a dark-weathering care, and Zacanthoides are the most com- lithologic-topographic change similar to lower Millard Member. monly represented genera. According to that at the top of the Whirlwind interval Samples from the upper Howell Lime- Oldroyd (1973), the trilobite species appear has been used in central Utah (Fig. 3) to stone (Table 2) yielded an average 3.8 per- to be strongly facies controlled, and to have mark the top of the Ophir and Shadscale cent insoluble residue. Quartz, mostly in occupied a variety of shallow shelf-lagoon Formations. the 0.5- to 0.1-mm range, constitutes most and near—sea-level shoal environments. The Whirlwind Formation, particularly of the residues, with clay predominant in a in its upper part, is characterized by co- few samples. Mica and ferromagnesian Dome Limestone quinas of disarticulated Ehmaniella. In minerals make up less than 1 percent of the west-central Utah the Ehmaniella fauna is residues. Upper Howell Limestone is fine Walcott's (1908a, p. 11) designation of still undescribed, but preliminary study in- grained, apparently formed mostly from this formation in the House Range has been dicates both stratigraphic and geographic finely divided lime mud. White calcite used by all later workers (Fig. 2), although changes in species composition. Low blebs, common in some beds, are the Walcott's (1908b, p. 182) description is so species diversity and great abundance of in- "bluebird structures" described by Mer- brief that Deiss' (1938) and Hanks' (1962) dividuals in most fossiliferous beds suggest riam (1964, p. 37) and may be a product of measured sections are useful supplements. deposition in unstable environments. the calcitization of dolomite (J. C. Kepper, The Dome Limestone is easily mappable in Samples from the Whirlwind Formation 1974, written commun.) Algal pisolites and the House Range and adjoining ranges (Fig. range greatly in percentage of insoluble res- laminated structures are rare. Other fossils 3) because it is a cliff-forming massive idue — from 1 to 93 percent, averaging 26 have not been reported from the upper limestone between two slope-forming shaly percent (Table 2). The residue is chiefly member of the Howell Limestone in the limestone formations. Walcott's (1908a, clay, but three residues near the top of the House Range, but Robison has collected 1908b) description of the Dome as a formation are mostly subangular quartz in Glossopleura sp. from 5 m above the base "siliceous limestone" is misleading. Insolu- the 0.5- to 0.1-mm size range. of the member in the Cricket Range. ble residue makes up between 0.6 and 5.0 percent of our samples and averages 1.8 Swasey Limestone Chisholm Formation percent (Table 2). Clay minerals form the bulk of the residue in most samples, but Walcott (1908a) defined the Swasey Robison (1960, p. 49) proposed that finely divided quartz (some as minute Limestone and recognized a lower and Chisholm be extended as a formation name euhedral crystals) is the chief constituent in upper part (1908b, p. 174) and its type sec- from Pioche, Nevada (Fig. 3, col. 1), where about one-third of the samples. A trace of tion on the southwest slope of Swasey Peak. this shale and interbedded limestone unit ferromagnesian minerals was noted in sam- Deiss (1938, p. 1145-1146) recommended was named by Walcott (1916, p. 409). ples from the upper two-thirds of the for- that a better reference section for the Merriam (1964, p. 32) noted that 30 per- mation. Swasey was in Marjum Canyon, where he cent of the Chisholm at Pioche consists of Although the Dome Limestone forms a measured a cliff-forming upper 85 m and a limestone; the proportion of limestone is light-gray cliff, on fresh surfaces the lime- shaly slope-forming lower 36 m. Wheeler even greater in the House Range (Deiss, stone is mostly medium to dark gray and (1948) proposed that the two parts of the 1938, p. 1135-1136; Hanks, 1962, p. medium to fine grained. Oolites and small- Swasey be recognized as separate members, 123), and the designation Chisholm Forma- scale cross-bedding are common in the but Robison (1960, p. 51) restricted the tion is more appropriate here. middle of the formation and suggest deposi- Swasey (Fig. 2) to the upper cliff-forming The Chisholm Formation is an easily tion in shallow water. Fossils are rare in the part of Walcott's original Swasey Lime-

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stone and proposed a new formation name composed of slope-forming laminated argil- Bathyuriscus-Elrathina Zone and is here for the lower part. laceous limestone or calcilutite with an informally called the Ptychagnostus gibbus The restricted Swasey Limestone, like the agnostoid-rich trilobite fauna characterized fauna (Fig. 3). In the Wheeler Amphitheater Dome Limestone, is remarkably pure lime- by a new subspecies of Ptychagnostus gib- of the House Range, only the uppermost stone, bounded above and below by shaly bus. As White (1973, PI. 6, fig. 4) has 40 m of the Wheeler Shale has abundant fos- units. Samples (Table 2) average 1.8 per- shown, the lithofacies change is abrupt and sils, and that locality is one of the few cent insoluble residue that is mostly clay or may even display truncated fragments of known where the lower part of the forma- quartz of varying proportions. In a few fossils below the contact. In the House tion is unfossiliferous. The upper 240 m of samples the quartz occurs as small crystals; Range, the boundary surface has local relief the Wheeler in the Drum Mountains con- pyroxene is a noticeable trace in several of as much as 15 cm and may represent a tains the thickest and most fossiliferous samples. Descriptions of Swasey Limestone diastem. At some localities in the House lower Bolaspidella Zone sequence currently by Deiss (1938) and Hanks (1962) indicate and Fish Springs Ranges, "cannonball" known (White, 1973). that oolitic and pisolitic limestones, which concretions composed of agnostoid co- Insoluble residues from samples in Mar- suggest shallow-water deposition, are quinas can be found in the basal 2 m of the jum Canyon (Table 2) range from 10 to 70 common in all but the uppermost part. formation. Similar concretions, but with a percent of the rock and average 45 percent. Fossils are common only in the upper- somewhat different agnostoid fauna, occur Clay constitutes most of the insoluble frac- most beds of the Swasey Limestone, and 30 m above the Glyphaspis beds in the tion, with finely divided subangular silica then occurrence may be sporadic along Wasatch Mountains east of Huntsville, constituting less than one-fourth of the res- strike. A diverse fauna with 31 species of Utah. idue. Robison (1960, 1964c) concluded nonagnostoid trilobites has been described Flaggy argillaceous limestone and cal- that the Wheeler Shale is a tongue of clastic by Randolph (1973) from the upper Swasey careous shale like the Wheeler can be rec- material extending eastward into Utah Limestone in the Drum Mountains. The ognized in most ranges to the north and from an "outer detrital belt" in Nevada. fauna is informally named for Glyphaspis east of the House Range at least as far as (Fig. 3), one of its most common genera. the Deep Creek, Lakeside, Promontory, and Marjum Formation Other common forms are Parkaspis, Ton- Canyon Ranges and the Wasatch Moun- kinella, Pagetia, Zacanthoides, Dorypyge, tains. However, temporally equivalent, Robison (1964c) reviewed the history and a number of new genera. Collecting by massive, cliff-forming Eye of Needle Lime- and usage of this formation and recom- Robison indicates that the Glyphaspis stone (new name) is found to the southeast mended that the name not be extended fauna is present in many of the ranges of the and south of the House Range in the Crick- beyond the House Range because (p. 1003) eastern Great Basin, and it constitutes a et Range and Wah Wah Mountains (Fig. "rocks of the type locality possess a combi- useful marker for correlation. White (1973, 3). The Wheeler Shale in the Drum Moun- nation of lithologic characters that are not p. 18) concluded that the Glyphaspis fauna tains is the same as "Limestone G" of Crit- closely duplicated in any other described of the Drum Mountains probably accumu- tenden and others (1961). Biostratigraphy area of the eastern Great Basin." Geologic lated along the seaward sides of shallow- and depositional environments of the for- mapping by Hintze in the House and Fish shelf shoals. mation in the Drum Mountains were Springs Ranges and the Wah Wah Moun- studied in detail by White (1973), who tains has substantiated this conclusion. Wheeler Shale found that in the southern part of the area Walcott (1908a, p. 10) designated the the Wheeler is 304 m thick, rather than cliffs on the south side of Marjum Pass in Tens of thousands of beautifully pre- 94 m thick as previously reported by Rob- the House Range as the type locality. Mar- served trilobite specimens, chiefly Elrathia ison (1964c, p. 1001). In the Dugway jum Formation at this location was mapped kingii (Meek), from the upper part of the Range the upper part of the Trailer Lime- by Hanks (1962) on a planimetric base Wheeler Shale are distributed in collections stone of Staatz and Carr (1964) is equiva- map, and Hintze (1974b) showed the Mar- throughout the world and have made this lent to the Wheeler. In the Wasatch Moun- jum contacts on a topographic base. At formation famous. Walcott's name (1908a) tains east of Ogden, Rigo's (1968, p. 40) Marjum Pass the Marjum-Weeks boundary and description (1908b, p. 174, 181) of the "upper shale member of the Ophir Forma- is placed at the top of the cliffs, and the Wheeler designate a unit that has been tion" can be correlated lithologically and Weeks Limestone underlies the back slope mapped by Hintze in the House and Fish faunally with the Wheeler Shale. The south of the cliff line. As Robison (1964c, Springs Ranges. Robison (1964c, p. 1000— "middle limestone member" of Rigo's p. 1001) pointed out, the Marjum Forma- 1001) reviewed the lithologic characteris- Ophir Formation is approximately equiva- tion changes facies rapidly within the tics and areal extent of the formation as lent to the Swasey Limestone of the House House Range, becoming more limy and less known at the time. Range, and his "lower shale member" ap- shaly north, east, and south from Marjum pears to correlate with the type Ophir Shale As noted previously (Robison, 1960, p. Pass. Accordingly, Figure 3 shows that dif- in the Oquirrh and East Tintic Mountains. 47-49, Figs. 1, 3; 1964c, p. 997-1000, ferent nomenclature is recommended for Figs. 2, 3), the boundary between the Fossils from the Wheeler Shale of the the north end (col. 3) and for the south end Swasey Limestone and the Wheeler Shale House Range have most recently been de- (col. 5). represents a major shift of lithofacies. This scribed and summarized by Robison Limestone samples from the Marjum lithofacies boundary has now been ex- (1964a, 1965, 1971) and Sprinkle (1973). Formation at Marjum Pass average 21 per- amined by Robison at numerous localities Additional collections now show the bound- cent insoluble residue (Table 2). Clay min- from as far west as the Eureka district in ary between the Bathyuriscus-Elrathina erals compose three-fourths of the residue, central Nevada to as far east as the Wasatch and Bolaspidella Zones to be located about and finely divided subangular silica almost Mountains and Canyon Range in central one-fifth of the way up in the Wheeler For- all the rest. Mica and pyroxene occur as a Utah. At most localities the uppermost mation in the House Range and Drum trace in a few samples. Swasey or its equivalent horizon in other Mountains, rather than at the base of the The Marjum Formation at Marjum Pass formations consists of cliff- or ledge- formation as reported earlier (Robison, and at Wheeler Amphitheater 15 km to the forming biosparite limestone with a diverse 1964a, 1964c). A large and mostly unde- northeast contains the most complete trilo- Glyphaspis fauna. The overlying basal beds scribed fauna from many localities in bite succession known for this part of the of the Wheeler or its equivalents usually are Nevada and Utah represents the upper Cambrian in the Great Basin (Fig. 3). The

fauna has been described and zoned by Robison (1964a, 1964c), and his zones are shown in Figure 3.

Weeks Limestone

Robison (1964c) reviewed the naming and age assignments of the Weeks Lime- stone. Mapping by Hintze (1974b, 1974c, 1974f) indicates that the term "Weeks" can be applied only at its type section in Weeks (now North) Canyon on the Notch Peak quadrangle; elsewhere other formational terminology is needed (Fig. 3). The Weeks Limestone in its type area south of Marjum Pass is most readily differentiated from the Marjum and Orr Formations on the basis of its topographic expression as a slope- and valley-forming unit between more resistant ledge- and cliff-forming units. In the Figure 4. Eye of Needle Limestone (e) forms light-gray cliff. Darker ledges above are Pierson Cove area of Marjum Pass, hand specimens from Formation (pc); darker beds beneath Eye of Needle are Swasey Limestone (s). Grass-covered thin band the Marjum Formation and Weeks Lime- at base of hill is Whirlwind Formation (w), beneath which upper part of Dome Limestone (d) is partly stone are not much different, but the Weeks covered with juniper trees. Photo of west face of Wah Wah Mountains from Utah State Highway 21, is more uniformly thin bedded and fine toward southeast. grained. Samples from both formations av- tended for mapping purposes into the Fish graphic map. Eye of Needle is a long thin erage about 20 percent insoluble residue, Springs and Cricket Ranges and the Wah slit or "natural bridge" eroded along a frac- and those from the Weeks are mostly finely Wah Mountains (Figs. 1, 3). Facies changes ture within the formation to which the divided silica, whereas those from the Mar- in Cambrian strata between the Swasey name is being applied. Because a strike fault jum are mostly clay. Equivalents of the Limestone and the widespread bioclastic cuts the formation in sec. 36, the type sec- Weeks Limestone to the east, north, and limestone of the lower Orr Formation make tion is designated 1.3 km to the north in the south (see Fig. 3) are more limy and, ac- it impossible to use the Marjum and Weeks northwest quarter of sec. 25, T. 26 S., R. 16 cording to Robison (1964c, Fig. 2-F), rep- as recognizable map units throughout W. Here the entire formation is exposed un- resent a cleaner carbonate lithosome, into west-central Utah, and the Wheeler cannot faulted between the Swasey Limestone and which the shalier Weeks Limestone extends be recognized south or southeast of the the Pierson Cove Formation (Hintze, as a tongue from the west. At the Weeks- House Range. The Trippe Limestone and 1974f). Orr boundary, rock composition changes Lamb Dolomite, formations established by The Eye of Needle Limestone is com- substantially from fine-grained siliceous Nolan (1935) in the Deep Creek Range, can posed almost entirely of massive limestone, limestone to coarse-crystalline bioclastic be extended into certain other ranges, but fine to medium grained and mostly light limestone typical of the lower Orr Forma- some rock sequences were encountered for gray, although some horizons are mottled tion. which no established nomenclature exists. or banded with dark-gray zones. The mid- At least two trilobite zones are present in The following formations are defined to dle one-third contains about 30 percent the Weeks Limestone. The Lejopyge calva designate these sequences. Bed-by-bed de- white calcite as fillings in small rods or Subzone of the upper Middle Cambrian scriptions of the type sections of these new tubes, which are crudely bedded and which Bolaspidella Zone is found in the lower 50 formations are available from Hintze and in the Pioche area have been called 1 m of the formation (Robison, 1964a, p. from the Geological Society of America. "bluebird structures" by Merriam (1964, p. 513). Cedaria, Tricrepicephalus, and other 37). The Eye of Needle Limestone is 62 m trilobites typical of the lower Upper Cam- Eye of Needle Limestone (New) thick in the type section, but the formation brian are found throughout the upper 280 varies somewhat in thickness in the rela- m of the formation (Robison, 1964c, p. Lithology characteristic of the Wheeler tively short distance it is exposed along the 1007). They belong to the Cedaria- Shale is conspicuously absent from the west front of the Wah Wah Mountains. It is Crepicephalus Zones as used in other parts Cambrian section in the Wah Wah Moun- as much as 80 m thick just south of the edge of North America, but the biostratigraphy tains, as noted by Wheeler (1948, p. 40). Its of the Wah Wah Summit quadrangle. of the interval is still inadequately known place in the stratigraphic sequence above Eye of Needle basal contact with the in the Great Basin. The position of the the Swasey Limestone here is occupied by a Swasey Limestone is conformable and is Middle-Upper Cambrian boundary falls massive limestone that forms bold cliffs placed at a color change and at a break in within an unfossiliferous interval from 50 along the west face of the Wah Wah Moun- slope. Eye of Needle forms light-gray to 85 m above the base of the Weeks tains southward from where Utah State steeper cliffs, and Swasey forms less steep (Robison, 1964b; 1964c, p. 1007). Highway 21 crosses the central part of the cliffs and slopes of darker limestone. range (Fig. 4). The contact between the Eye of Needle NEW MIDDLE AND UPPER The name is taken from the feature so Limestone and the overlying Pierson Cove CAMBRIAN FORMATIONS designated in sec. 36, T. 26 S., R. 16 W. on Formation is conformable and somewhat the 1960 Wah Wah Summit 15' topo- transitional because the same lithologies Formation names used in the central that make up the lower Pierson Cove are House Range, from the Prospect Mountain also found, in somewhat different propor- 1 Quartzite through the Swasey Limestone, Copies of GSA supplementary material 75-16 may be tion, in the highest beds of the Eye of Nee- ordered from Documents Secretary, Geological Society as discussed in the preceding section and of America, 3300 Penrose Place, Boulder, Colorado dle Limestone. In mapping (Hintze, 1974f), shown in column 4 of Figure 3, can be ex- 80301. the contact was placed where massive cliffs

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characteristic of the Eye of Needle Lime- Mountains is conformable and gradational, 3, col. 2). Nolan (p. 12) noted that although stone give way topographically to the but it was mapped (Hintze, 1974f) at the mottled limestone makes up most of the prominent slope-forming zone, composed change from the dark-gray cliffs of the Pier- formation, "the most striking parts of the largely of light yellowish-gray laminated son Cove Formation to the alternating formation are the finely laminated white or dolomitic boundstone of the basal Pierson light- and dark-gray banded slope- and cream-colored beds." Bick (1966) Cove Formation. ledge-forming beds of the lower Trippe confirmed Nolan's description of the for- Fossils have not been found in the Eye of Limestone (Fig. 5). mation and extended it southward in the Needle Limestone, but it is certainly Middle On aerial photographs, the type Pierson Deep Creek Range. Kepper (1972) ex- Cambrian in age because it is bracketed by Cove Formation in the Wah Wah Moun- tended the term to the Fish Springs Range, fossiliferous Middle Cambrian strata (Fig. tains comprises eight light and dark bands Utah, and the Schell Creek Range, Nevada, 3). It is tentatively correlated with the as follows: and noted that similar strata are included Wheeler Shale. within the Highland Peak Formation in Band 8 dark cliff (top) 144 m southern Nevada. The light dolomitic lami- Band 7 light ledges 31 m nated boundstones that are the most con- Pierson Cove Formation (New) Band 6 dark cliff 95 m Band 5 light ledges 13 m spicuous part of the formation seem to be Above the light-gray massive cliff- Band 4 dark cliff 94 m concentrated in, although not exclusive to, forming Eye of Needle Limestone in the Band 3 white slope 12 m this part of the uppermost Middle Cam- Wah Wah Mountains is a thick sequence of Band 2 dark ledges 14 m brian sequence in western Utah. Kepper dark-gray limestones and dolomites that Band 1 white slope 36 m (1972, p. 505) plotted the regional strati- Total Pierson Cove are here named the Pierson Cove Formation 440 m graphic occurrence of these distinctive after the valley of that name shown on the Formation thickness rocks and showed that they are found to 1960 Wah Wah Summit topographic quad- The Pierson Cove Formation is virtually some extent in strata both above and below rangle map. The type section is located in unfossiliferous except for algal boundstone the Trippe Limestone as defined by Nolan. NW'A sec. 23, T. 26 S., R. 16 W., about 2 and bioturbation structures. Robison has Extension of the name Trippe Limestone km south of Pierson Cove. The Pierson collected a single cranidium of into areas beyond the Deep Creek Range Cove Formation is easily identified in the Brachiaspidion sp. from about 230 m has been facilitated by recognition of the field and on air photos because it forms the above the base of the formation in the regional extent of an Eldoradia-bearing darkest (almost black) outcrops in the NE1/« sec. 26, T. 25 S., R. 16 W. The trilo- unit composed of shaly limestone and in- range (Fig. 5). bite probably belongs to the Bathyuriscus traformational limestone conglomerate. It The Pierson Cove Formation is equiva- fimbriatus Subzone (Fig. 3). Kepper (1974) makes up the uppermost one-sixth of the lent to the lower part of the Marjum For- suggested variable salinity conditions as a Trippe Limestone and is here assigned mation (Fig. 3) but lacks the shaly detritus cause for an antipathetic relation between member status. The combination of that characterizes the Marjum. Lithologi- Middle Cambrian trilobites and stromatoli- boundstone-bearing rocks in the lower cally the Pierson Cove Formation is similar tic algae. Some of his evidence came from Trippe and ubiquitous Eldoradia-be&nng to much of the Highland Peak Formation of rocks that here are assigned to the Pierson intraformational conglomerate at the top southeastern Nevada. However, there Cove Formation. enables widespread recognition of the seems to be no way to accurately extend the Trippe Limestone as a mappable unit in named and numbered members of the Trippe Limestone western Utah (Hintze, 1974a). Highland Peak (Fig. 3, col. 1) into the Wah Lower Member of Trippe Limestone. Wah Mountains and other ranges in Utah This formation was defined by Nolan The alternating mottled lime mudstone and for use as map units. No other area in Utah (1935) in the Deep Creek Range, Utah (Fig. laminated dolomitic boundstone that has stratigraphic nomenclature that can be satisfactorily used for this interval in the Wah Wah Mountains. The Pierson Cove Formation is composed chiefly of three lithologies repeated throughout the upper Middle Cambrian section in varying proportions in the different formations and members. Predominant lithology in the Pierson Cove is dark-gray lime mudstone mottled with light-olive to brownish-gray dolomitic mudstone. Next most common is massive fine-crystalline medium-gray limestone, sometimes containing small rods or tubes filled with white calcite. Least common, but nonetheless conspicuous, is yellowish-gray laminated dolomitic boundstone that forms white bands at the base, in the middle, and near the top of the formation. Kepper (1972) described these lithologies in some detail and suggested that they represent a shoal facies, as compared to a slightly deeper water open-shelf facies represented by the shaly Figure S. West face of Wah Wah Mountains near Pierson Cove. Dark cliffs in lower one-third of Marjum Formation. hill are Pierson Cove Formation (pc); light-banded slope in middle is lower member of Trippe The contact of the Pierson Cove Forma- Limestone (tl); Fish Springs Member of Trippe Limestone (tf) forms slope thinly covered with juniper tion and Trippe Limestone in the Wah Wah trees; top of hill is cliffs of ledgy member of Wah Wah Summit Formation (ws).

characterize the lower part of the Trippe Nolan's unit 4. Palmer (1971, p. 36) also Peak Formation as defined by Wheeler and Limestone are widely distributed in western reported Eldoradia from the upper Trippe Lemmon (1939). Kepper (1972) has traced Utah. Their origin and distribution is dis- there. Bick (1966, p. 33) added to Nolan's this unit in many ranges in western Utah cussed in some detail by Kepper (1972), description by noting that "the upper 183 and eastern Nevada and believes (p. 507) who correlated them with unit J of the feet of Trippe . . . contains many beds of that much of the rock formed in tidal flat Highland Peak Formation of southeastern flat-pebble conglomerate. Mud cracking is environments. Nevada. Unit J, along with units K and L of common. . . ." Hintze examined the type Fauna of the Fish Springs Member sup- Wheeler and Lemmon (1939), have been section of the Fandangle Limestone de- ports the interpretation of tidal-flat envi- grouped by Merriam (1964, p. 48) into his scribed in the Dugway Range by Staatz and ronments. Usually only a single species, unit 9 (Fig. 3, col. 1). Carr (1964, p. 23) and correlated their Eldoradia prospectensis, is encountered. It In the Wah Wah Mountains, the Trippe units 1 to 4 with the Fish Springs Member. occurs sporadically, but large numbers of Limestone forms a conspicuous band along Unit 4, shown as "covered" in their meas- disarticulated skeletal parts tend to be con- the west face of the range north of Utah ured section, was found exposed, just centrated in lenses and small channel-fill State Highway 21. A well-exposed, virtu- downslope from their section traverse. deposits. The scattered occurrence of large ally unbroken reference section in the There it consists of about 80 percent fissile numbers of individuals but low taxonomic northeast quarter of sec. 12, T. 26 S., R. 16 green shale and about 20 percent thin- diversity suggests unstable environments. W. (Hintze, 1974f) is made up of alternat- bedded nodular limestone and intraforma- The Lejopyge- bearing parts of the upper ing laminated boundstone and mottled lime tional conglomerate that bears Eldoradia Marjum Formation and lower Weeks mudstone in approximately a 2:3 propor- fragments. Crittenden and others (1961, p. Limestone (Fig. 3) probably are approxi- tion and totaling 164.2 m for the lower 502, PI. 20) designated the interval of the mate temporal equivalents of the member. Contacts with adjacent units are Fish Springs Member as their "Limestone Eldoradia-bearing Fish Springs Member, conformable and somewhat gradational. J," which they showed as a separate map but they appear to represent deposition in The top of the lower member is placed at unit. We examined this unit in the Drum open, deeper, and more normal marine en- the topographic break between low ledges Mountains and found beds of intraforma- vironments. of the lower member and the covered slope tional conglomerate in the upper part to Eldoradia is known from several that characterizes the Fish Springs Member contain E. prospectensis and Blainia? sp. localities in central and eastern Utah. Rigo in the Wah Wah Mountains. The Fish Springs Member in the Cricket (1968, p. 39) reported it from the Calls Fort Although the lower Trippe Limestone is Range is 26 m thick and contains E. pros- Shale Member of the Bloomington Forma- believed to be equivalent to part of the pectensis in the upper part. The member tion in Ogden Canyon. Morris and Lover- upper Marjum Formation of the House was mapped separately in the Wah Wah ing (1961, p. 43) reported Eldoradia from Range (Fig. 3), fossils have not been ob- Mountains (Hintze, 1974f), where it con- the upper part of the Cole Canyon Dolo- tained from the lower Trippe to verify this tains E. prospectensis, and in the southern mite in the East Tintic Mountains. correlation. Nor does the Marjum contain (Black Hills) part of the House Range Lautenschlager (1952) reported it from the any laminated boundstone to enable lithic (Hintze, 1974c). Cole Canyon Dolomite in the central Pav- correlation, although there are a few very The name for the member is taken from ant Range. Robison has identified thinly bedded, nearly laminated limestones the Fish Springs Range, which contains the Eldoradia in Mountain Fuel Supply Com- in the lower part of the Weeks Limestone. best exposed and most fossiliferous and pany well cores from depths of 3,481 m in As suggested by Robison (1960, 1964c), some of the most accessible exposures of the Clay Basin on the north flank of the Palmer (1971) and Kepper (1972), the the unit. A reference section was measured Uinta Mountains, Daggett County, Utah, House Range strata in this part of the sec- at 6,000-ft elevation on the east face of the and 2,362 m in the South Last Chance tion represent an "outer detrital belt" or range in NEV4, SW'A, sec. 33, T. 12 S., R. anticline, Emery County, Utah. The El- "open shelf' environment, in contrast to 14 W. Uppermost ledges of the lower doradia fauna is widespread in Utah, and the "middle carbonate belt" or "near-sea- Trippe Limestone here are composed of in many areas it is the only persistent fauna level shoals" represented by the Trippe light orangish-yellow laminated bound- in what is otherwise a mostly barren inter- Limestone. stone capped with a 2-m bed of pisolitic val between the Ehmaniella fauna of the The lower member of the Trippe Lime- mottled lime mudstone. The lowest 30 m of middle Middle Cambrian and a widespread stone includes units 6 to 19 of Nolan's the Fish Springs Member is olive-green Crepicephalus fauna of the lower Upper (1935, p. 12) type section. In addition, this shale interbedded with equal amounts of Cambrian. member is recognized in the Fish Springs thin-bedded medium-gray limestone, of and Cricket Ranges and the Wah Wah which one-third is flat-pebble intraforma- Wah Wah Summit Formation (New) Mountains (Fig. 3), and it correlates with tional limestone conglomerate. This unit units 5 to 12 of the Fandangle Limestone of forms talus slopes and is exposed only in In the Wah Wah Summit quadrangle, this Staatz and Carr (1964, p. 23). steep gullies. The middle 7 m is medium- to resistant formation is clearly delimited at its Fish Springs Member of Trippe Lime- dark-gray, thin-bedded mottled limestone base by the slope formed on the Fish stone (New). The uppermost part of the that forms low ledges. The uppermost 6 m Springs Member of Trippe Limestone. The Trippe Limestone shows such a distinctive is medium- to dark-gray silty, thin-bedded top of the formation is placed at the top of a lithologic change from beds above and . limestone that forms slopes beneath the white marker member, which is a dolomite below that it is emphasized with a formal massive cliffs of the Lamb Dolomite. Total boundstone and limestone unit nearly 50 m name. This member usually forms a soil- or thickness of the Fish Springs Member here thick and is the most conspicuous white talus-covered slope beneath massive ledges is 43 m. Fossils from this reference section band of strata seen in any part of the Cam- and cliffs of the Lamb Dolomite or equiva- have been identified by Robison as brian section in the Wah Wah and southern lent overlying formations. Units 1 to 5 of Eldoradia prospectensis (Walcott) at 1.5, House Ranges. Nolan's (1935, p. 12) type section consti- 3.0, 6.0, 7.5, 12.0, 15.0, and 18.0 m above The name is taken from Wah Wah Sum- tute this member and are designated as the base, and coquinas of an undetermined sol- mit, the highway pass in the middle of the type section for the new member. We ob- enopleurid trilobite at 21.0 and 24.0 m. Wah Wah Mountains. The Wah Wah tained Eldoradia prospectensis (Walcott), The Fish Springs Member is approxi- Summit Formation is extensively marble- Blainia n. sp., and Bolaspidella sp. from mately equivalent to unit K of the Highland ized around intrusions in the pass area.

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Therefore, the type section is located 14 km SUMMARY Bull. 77, 120 p. to the north along the west foothills of the Crittenden, M. D., Jr., Straczek, J. A., and range in NE1/» sec. 23, T. 25 S., R. 16 W. The House Range contains the most con- Roberts, R. J., 1961, Manganese deposits in Two subunits, here informally designated tinuously fossiliferous Middle Cambrian the Drum Mountains, Juab and Millard ledgy (lower) and white marker (upper) sequence in western Utah. On the basis of Counties, Utah: U.S. Geol. Survey Bull. 1082-H, p. 493-544. members, are recognized in the Wah Wah lithologic and paleontologic correlation, Crittenden, M. D., Jr., Schaeffer, F. E., Trimble, Mountains and the southern House and formational units from the lower part of D. E., and Woodward, L. A., 1971, Cricket Ranges. The ledgy member, as the this sequence can be recognized in several Nomenclature and correlation of some name implies, forms ledges and cliffs that adjacent ranges within at least 80 km. The Upper Precambrian and basal Cambrian rise steeply above the Fish Springs Member upper part of the House Range sequence is sequences in western Utah and southeastern slope. In the Wah Wah Mountains the unique. The formational names Marjum Idaho: Geol. Soc. America Bull., v. 82, p. ledgy member is 251 m thick at its type and Weeks, which are valid map units in 581-602. section. The lower 105 m of the ledgy the central House Range, where they were Deiss, Charles, 1938, Cambrian formations and member consists mostly of light-gray, established by Walcott (1908a), should not sections in part of Cordilleran trough: Geol. fine-grained massive limestone containing be extended into other areas. Soc. America Bull., v. 49, p. 1067-1168. small rods of white calcite; this is interbed- Hague, Arnold, 1883, Abstract of report on the Hintze (1974b, 1974c, 1974d, 1974e, geology of the Eureka district, Nevada: U.S. ded with dark-gray mottled limestone and 1974f) has delimited new rock units in the Geol. Survey 3rd Ann. Rept., p. 237-290. dolomite. The upper 146 m of the ledgy Wah Wah Mountains and other areas for Hanks, K. L., 1962, Geology of the central member here consists mostly of mottled the upper Middle Cambrian and lower House Range, Millard County, Utah: dolomitic limestone, with pisolites common Upper Cambrian: Eye of Needle Limestone, Brigham Young Univ. Geol. Studies, v. 9, in the lower half. The white marker Pierson Cove Formation, Trippe Limestone pt. 2, p. 115-136. member is 48 m thick in the Wah Wah (extended, with new Fish Springs Member Hintze, L. F., 1963, Geologic map of Utah, Summit quadrangle type section, where it defined), and Wah Wah Summit Forma- southwest quarter: Utah Geol. and consists of light-gray laminated dolomite tion. Most of these units consist of varying Mineralog. Survey separate map, scale 1:250,000. and limestone that make up nearly one- proportions of mottled dolomitic lime- 1974a, Eldoradia, a helpful arthropod third of the member, interbedded with mot- stone, massive limestone with white calcite tled limestone beds 1 to 2 m thick. The unit amongst barren boundstones in western rods, and laminated dolomitic boundstone. Utah: Geol. Soc. America Abs. with Pro- forms a slope less resistant than the ledgy According to Kepper (1972), these rocks grams, v. 6, no. 3, p. 192—193. member below or the Orr Formation originated as lime mud and algal mats in a 1974b, Preliminary geologic map of the above. broad shoal area near sea level. They ac- Notch Peak quadrangle, House Range, Mil- It is thought that the Wah Wah Summit cumulated in the Wah Wah Mountains area lard County, Utah: U.S. Geol. Survey Misc. Formation is equivalent to the Lamb to a thickness of almost 1,000 m. The car- Field Studies Map MF-636, scale Dolomite of the Deep Creek Range (Fig. 3). bonate units named are remarkably devoid 1:48,000. 1974c, Preliminary geologic map of the The Nolan (1935, p. 13) described pisolites and of trilobites, with the exception of the Fish Springs Member of the Trippe Limestone, Barn quadrangle, Millard County, Utah: oolites as being common in the type Lamb U.S. Geol. Survey Misc. Field Studies Map which contains a widespread Eldoradia Dolomite, and said that "the bulk of the MF-633, scale 1:48,000. formation ... is composed of a light to fauna, and therefore serves as a useful 1974d, Preliminary geologic map of the medium gray dolomite mottled by patches marker horizon. Conger Mountain quadrangle, Millard of darker dolomite containing white rods. County, Utah: U.S. Geol. Survey Misc. . . ." Thus, the sequence and proportion of ACKNOWLEDGMENTS Field Studies Map MF-634, scale 1:48,000. lithologies differ between the ledgy member 1974e, Preliminary geologic map of the of the Wah Wah Summit Formation and This paper is an outgrowth of field exer- Crystal Peak quadrangle, Millard County, the Lamb Dolomite, and the uppermost Utah: U.S. Geol. Survey Misc. Field Studies cises conducted in western Utah since 1955 Map MF-635, scale 1:48,000. beds are quite different. Nolan further de- by students and faculty of the Department 1974f, Preliminary geologic map of the Wah scribed the uppermost 30 m (150 ft) of of Geology, Brigham Young University. Wah Summit quadrangle, Millard and Lamb Dolomite as "thin bedded dolomite Ralph Holmgren of the U.S. Forest Service Beaver Counties, Utah: U.S. Geol. Survey with partings of yellow or red sandy shale, provided camp facilities at the Desert Misc. Field Studies Map MF-637, scale together with a few massive dolomite beds Range Experiment Station, and William 1:48,000. . . . the top 25 to 50 feet of this zone is Hewitt, former director of the Utah Geolog- Kepper, J. C., 1972, Paleoenvironmental pat- made up of a reddish weathering fine ical and Mineralogical Survey enthusiasti- terns in Middle to lower Upper Cambrian grained sandstone. . . ." Staatz and Carr cally supported this project. Max D. Crit- interval in eastern Great Basin: Am. Assoc. (1964) found similar rocks in the Dugway tenden was instrumental in initiating a Petroleum Geologists Bull., v. 56, p. 503-527. Range and extended Nolan's Lamb Dolo- cooperative program with the U.S. Geolog- mite into that range as a map unit. Differ- 1974, Antipathetic relation between Cam- ical Survey. Allison R. Palmer and Hal T. brian trilobites and stromatolites: Am. ences in the lithologies of the Lamb Dolo- Morris have been helpful in discussions of Assoc. Petroleum Geologists Bull., v. 58, p. mite and the Wah Wah Summit Formation Cambrian correlation problems. Robison's 141-143. are sufficiently great between the Deep faunal investigations were supported by Lautenschlager, H. K., 1952, Geology of the cen- Creek—Dugway area and the Cricket—Wah National Science Foundation grants tral part of the Pavant Range, Utah [Ph.D. Wah area (Fig. 1) that it is felt a new name GB-8745 and GA-43723. dissert.]: Columbus, Ohio State Univ., would better preserve the identity of both 188 p. formations. Merriam, C. W., 1964, Cambrian rocks of the REFERENCES CITED Pioche mining district, Nevada: U.S. Geol. The white marker member of the Wah Survey Prof. Paper 469, 59 p. Wah Summit Formation may be equivalent Bick, K. F., 1966, Geology of the Deep Creek Misch, Peter, and Hazzard, J. C., 1962, Stratig- to unit 13 of the Highland Peak Formation Mountains, Tooele and Juab Counties, raphy and metamorphism of late Precam- at Pioche, Nevada (Fig. 3). Utah: Utah Geol. and Mineralog. Survey brian rocks in central northeastern Nevada

and adjacent Utah: Am. Assoc. Petroleum 510-566. Cambrian Cordilleran formations: Smith- Geologists Bull., v. 46, p. 289-293. 1964b, Middle-Upper Cambrian boundary sonian Misc. Colin., v. 53, no. 1, p. 1-12. Morris, H. T., and Lovering, T. S., 1961, Stratig- in North America: Geol. Soc. America 1908b, Cambrian sections of the Cordille- raphy of the East Tintic Mountains, Utah: Bull., v. 75, p. 987-994. ran area: Smithsonian Misc. Colin., v. 53, U.S. Geol. Survey Prof. Paper 361, 145 p. 1964c, Upper Middle Cambrian stratig- no. 5, p. 167-230. Nolan, T. B., 1935, The Gold Hill mining dis- raphy of western Utah: Geol. Soc. America 1916, Cambrian trilobites: Smithsonian trict, Utah: U.S. Geol. Survey Prof. Paper Bull., v. 75, p. 995-1010. Misc. Colin., v. 64, no. 5, p. 409-410. 177, 172 p. 1965, Middle Cambrian eocrinoids from Wheeler, H. E., 1948, Late Precambrian- Oldroyd, J. D., 1973, Biostratigraphy of the western North America: Jour. Paleontol- Cambrian stratigraphic cross-section Cambrian Glossopleura Zone, west-central ogy, v. 39, p. 355-364. through southern Nevada: Nevada Univ. Utah [M.S. thesis]: Salt Lake City, Univ. 1971, Additional Middle Cambrian trilo- Bull., Geology and Mining Ser., no. 47, Utah, 140 p. bites from the Wheeler Shale of Utah: Jour. 58 p. Palmer, A. R., 1971, Cambrian of the Great Paleontology, v. 45, p. 796-804. Wheeler, H. E., and Lemmon, D. M., 1939, Basin and adjacent areas, western United Robison, R. A., and Hintze, L. F., 1972, An Early Cambrian formations of the Eureka and States, in Holland, C. H., ed., Cambrian of Cambrian trilobite faunule from Utah: Pioche districts, Nevada: Nevada Univ. the New World: London, Wiley- Brigham Young Univ. Geol. Studies, v. 19, Bull., Geology and Mining Ser., no. 3,57 p. Interscience, p. 1-78. pt. 1, p. 3-13. Wheeler, H. E., and Steele, Grant, 1951, Cam- Powell, D. K., 1959, Geology of the southern Sprinkle, James, 1973, Morphology and evolu- brian sequence of the House Range, Utah: House Range, Millard County, Utah: tion of Blastozoan echinoderms: Harvard Intermountain Assoc. Petroleum Geologists Brigham Young Univ. Research Studies, Univ. Mus. Comp. Zoology Spec. Pub., Guidebook 6, p. 29-37. Geol. Ser., v. 6, no. 1, 49 p. 284 p. White, W. W., Ill, 1973, Paleontology and Randolph, R. L., 1973, Paleontology of the Staatz, M. H., and Carr, W. J., 1964, Geology depositional environments of the Cambrian Swasey Limestone, Drum Mountains, and mineral deposits of the Thomas and Wheeler Formation, Drum Mountains, west-central Utah [M.S. thesis]: Salt Lake Dugway Ranges, Juab and Tooele Coun- west-central Utah [M.S. thesis]: Salt Lake City, Univ. Utah, 73 p. ties, Utah: U.S. Geol. Survey Prof. Paper City, Univ. Utah, 134 p. Rigo, R. J., 1968, Middle and Upper Cambrian 415, 188 p. Woodward, L. A., 1968, Lower Cambrian and stratigraphy in the autochthon and al- Stewart, J. H., 1970, Upper Precambrian and Upper Precambrian strata of Beaver Moun- lochthon of northern Utah : Brigham Young Lower Cambrian strata in the southern tains, Utah: Am. Assoc. Petroleum Univ. Geol. Studies, v. 15, pt. 1, p. 31-66. Great Basin, California and Nevada: U.S. Geologists Bull., v. 52, p. 1279-1290. Robison, R. A., 1960, Lower and Middle Cam- Geol. Survey Prof. Paper 620, 206 p. brian stratigraphy of the eastern Great Stokes, W. L., 1962, Geologic map of Utah, Basin: Intermountain Assoc. Petroleum northwest quarter: Utah Geol. and MANUSCRIPT RECEIVED BY THE SOCIETY JULY 1, Geologists Guidebook 11, p. 43-52. Mineralog. Survey separate map, scale 1974 1964a, Late Middle Cambrian faunas from 1:250,000. REVISED MANUSCRIPT RECEIVED NOVEMBER 18, western Utah: Jour. Paleontology, v. 38, p. Walcott, C. D., 1908a, Nomenclature of some 1974

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