Brigham Young University Geology Studies

Volume 27, Part 2

CONTENTS

The Kinnikinic Quartzite (Middle Ordovician) in the Type Area, Central Idaho, and a New Reference Section near Arco, Idaho ...... Robert Q. Oaks, Jr., and W. Calvin James

Geology of the Sage Valley 7 W' Quadrangle, Caribou County, Idaho, and Lincoln County, Wyoming ...... J ohn L. Conner

Geology of the Elk Valley Quadrangle, Bear Lake and Caribou Counties, Idaho, and Lincoln County, Wyoming .... J. Floyd Hatch

Geology of the Woodruff Narrows Quadrangle, Utah-Wyoming ...... Valen D. Ott

Geology and Ore Deposits of Mineral Mountain, Washington County, Utah ...... Stuart K. Morris

Conodonts and Biostratigraphy of the Lower Mississippian in Western Utah and Eastern Nevada ...... Gary J. Newman

Relative Age Determination of Quaternary Fault Scarps along the Southern Wasatch, Fish Springs, and House Ranges ...... Lee Piekarski

Geology and Mineral Deposits of the Lodi Hills, Nye County, Nevada ...... R. Blaine Rowley

The Flagstaff Formation: Depositional Environment and Paleoecology of Clastic Deposits near Salina, Utah ...... Steven W. Sperry

Geology of the Sewing Machine Pass Quadrangle, Central Wah Wah Range, Beaver County, Utah ...... Richard F. Wheeler

Publications and Maps of the Geology Department

Cover: Air photo of House Range fault scarp Courtesy of Lpe P~ekarski. A publicatioll of the Department of Geology Brigham Young Unrversiry

Provo, litah 84602

Editors

W. Ket~nethHamblin Cynthia hf. Gardner

Bllghdm Yomg linzwrfzrjv C;eolo~Stud~ei 17 published by rhe department. Geology Stud- 28 LonsIstS of graduate-student and staff rebearch In the department and occastonal paper\ from othe~contr~bucors Stadzesfor St~dmtssupplements the regular i~~esand IS lntetrded as a serles ut qhort papers of general Inrerest whlch ma? serve AS gu~desto the geolog of Utah for beginning students and laymen

ISSN 0068-1016 Distributed November 1980

l t -80600 46504 Conodonts and Biostratigraphy of the Lower Mississippian in Western Utah and Eastern Nevada*

GARYJ. NEWMAN bar Petroleum Corp. 1200 011 Center Buzldzng 2601 N.W. Expreway Oklahoma C~Q,Oklahoma 731 12

ABSTRACT-Lower Mlsslss~pplan rocks In western Utah and eastern Nevada are STRATIGRAPHY represented by the Joana Lmestone, the Madison Lmestone, and the comblned Carbonate rock from four formations of Lower Mis- F~tchv~lleFormation and Gardlson Llmestone Great vanabll~tyIn formation th~cknessesand the presence of unconform~t~esmake precise dat~ngand correla- sissippian age was collected and processed for this study. Of the tion difficult four formations, the Joana Limestone, of eastern Nevada and Nine sectlons between the Wasatch Mountalns on the east and Eureka, Ne- western Utah, was selected to be the basic time stratigraphic vada, on the west were sampled Sectlons lnclude Logan, Rock Canyon, Rattle- unit of study. The other three formations, F~tchvilleForma- snake Spur, North Stansbuly Mountalns, Needle Range, and Confus~onRange, Utah; and Wendover, Ely, and Eureka, Nevada Five Utah-Nevada zones were tion, Gard~sonLlmestone, and the Lodgepole Limestone (basal des~gnated,an Upper Devonian zone, three upper K~nderhookian zones, and Madison Group), are time stratigraphic equivalents to the one Valmeyenn zone No lower or m~ddleKlnderhook~an zones were recov- Joana Llmestone. ered The studled sectlons represent essentially equivalent tlme stratigraphic unlts spannlng the upper thlrd of the Klnderhookian. Exceptions to th~sare the Eureka and Wmdover, Nevada, sectlons wh~chare erosional remnants equlva- WESTERN UTAH AND EASTERN NEVADA lent to the lowest Carbon~ferous rocks In the other sectlons In central Utah, Joana Lmestone Devonlan conodont faunas are dlrectly overlam by late Klnderhooklan faunas, lndlcatlng the presence of a substantlal paraconformlty w~th~nthe Fitchvllle Hague (1883) proposed the name White Pine Shale for Format~on outcrops of shales and carbonate rocks in the White Pine INTRODUCTION mining district of Nevada. Hague's White Pine Shale included Lower Mississlpplan formations of the Great Basin have a lower calcareous shale, a siliceous limestone unit, and an up- been described for more than 100 years. They contain a rather per black argillaceous shale. The entire sequence was asslgned distinct coral-brachiopod fauna that led to reasonably sure rec- to the Devonian System. Spencer (1917) divided the Whlte ognition of an Early Mississrppian age. Originally the Lower Pine Shale into three separate units. The lower shale was re- Mississippian formations were zoned and correlated on the basis ferred to as the Pilot Shale, the Ilmestone as the Joana Lime- of these corals and brachiopods. The fauna is easily recognized stone, and the upper shale as the Chainman Shale. He assigned and commonly well preserved, but it does have some limita- the upper two unlts to the Mississippian System and tentatr- tions with respect to detailed correlation. One major limitation vely, because of lack of fossil evidence, considered the Pilot is that most of the corals and brachlopods are not particularly Shale to be Mississippian also. time restrictive but rather tend to be more facies restricted. In 1953 the Eastern Nevada Geological Association Stra- Slnce many of the Lower Mississippian rocks in the Great Basin tigraphic Committee (Easton and others 1953) recognized the have suffered minor to extreme secondary dolomicization, utility of Spencer's subdivision of the White Pine Shale into much of the macrofauna has been destroyed or rendered unrec- the three separate formations. They, however, preferred to as- ognizable. These problems, coupled with the bounding, above sign the three unlts the rank of members within the White and below, of many of the Lower Mississippian sections by un- Plne Shale. Nolan, Merrlam, and Williams (1956) rejected the conformities, have made correlation within the Lower MIS- concept of the White Pine Shale in favor of glvlng formational slssipplan of the Great Basin difficult and somewhat arbitrary. rank to the Chainman Shale, Joana Limestone, and Pilot Shale Conodonts within Lower Mississippian strata have been ex- because of difficulties in mapping the Wh~tePrne-Diamond tensively studied, and detailed zones have been determined. Peak boundary and the extensive stratigraphic range of the Thls fact, plus the widespread nature, ease of preservation, abili- shales referred to as White Pine Shale. In this paper the termi- ty to resist destruction during dolomitlzation, and ease of re- nology of Nolan, Merriam, and Williams (1956) is used, and covery from carbonate rocks, makes conodonts potentially un- the Joana Limestone is assigned formational rank (For a com- surpassed as time indicators for Lower Mississippian rocks of plete h~storyof stratigraphic terminology for the Lower Mis- the study area. sissippian of eastern Nevada, see Langenheim 1960). The study area Includes most of central Utah and east cen- The Joana Limestone is a shallow to deep miogeosynclinal tral Nevada: from the Wasatch Front on the east to Eureka, deposlt of uniform lithologic character (Sandberg and Poole Nevada, on the west, where the Lower Mississippian carbonates 1977). It consists largely of various limestones from micritic to essentially pinch out against the Antler uplift. Nine sectlons coarsely crystalline textures and typically contalns beds of were designated for collection and study (figs. 1-10). These sec- coarse crlnoidal debris and zones of chert, with small amounts tions were located to give best coverage of the study area, com- of interbedded shales and siltstones. pleteness of the vertical section, and, where possible, maximum Within the study area the Joana Limestone ranges in thick- new information. Previously mapped, measured, and described ness from 1000 feet south and east of the Ely Arch to a zero sections were used in this study to insure completeness of sec- edge in the area west of Eureka, Nevada, where it pinches out tions and accessibility and to eliminate any potential stratigra- .on . the flanks of the Devonian-Mississippian Antler orogenic phic or structural complications. belt. 'Thlr ppcr war rubmlrtcd m 1972 tn prrlal fulfillmmr of the rqummenrs for the dcgrec Mvrcr of Sclcncc th,lrrr charrmm, Morns S Pctcrvn Bccaux of a xrlcs of unfor- cvenrs, rhc ppcr war dclaycd xn publtcatton 104 G. J. NEWMAN

Six of the ten sections measured and collected for this Fitchville Formation study were from the Joana Limestone. Three sections were col- The Fitchville Formation is at most localities composed of lected in Nevada: 160 feet at Ely, 80 feet at Eureka, and 24 feet interbedded limestone and dolomite. However, dolomitization at Wendover. Three sections were also collected in western is pervasive in the Salt Lake City-Provo area of central Utah Utah; 230 feet in the Confusion Range, and sections of 930 and becomes less complete to the west, north, and south. Do- feet and 610 feet in the Needle Range. All sections produced lomitization has largely recrystallized the shelly macrofauna conodont material except the Ely section. of the Fitchville Formation, in most areas making identification of corals and brachiopods and precise correlation and dating CENTRAL UTAH difficult. Two formations in central Utah combine to closely approx- imate the time stratigraphic interval represented by the Joana The Fitchville Formation ranges in thickness from about Limestone of Nevada and western Utah. These two formations, 100 feet in the central Wasatch Mountains to about 400 feet in the Fitchville Formation and Gardison Limestone, were mea- the northern and southern Wasatch Mountains and west of the sured and collected as a single unit in all central Utah sections. Wasatch Front.

------_

Miles

FIGURE1.-Map showing location of sections collected during present study: 1.-Logan, Utah (see fig. 2); 2.-Rock Canyon, Utah (see fig. 3); 3.-Rattlesnake Spur. Utah (see fig. 4); 4.-North Stansbury Mms., Utah (see fig. 5); >.-Needle Range. Utah (see fig. 6); 6.-Confusion Range, Utah (see fig. 7); '/.-Wendover, Nevada (see fig. 8); 8.-Ely, Nevada (see fig. 9); 9.-Eureka, Nevada (see fig. 10). CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 105

FIGURE2.-Locality of Lodgepole Limestone section near Logan, Utah, NW%, FIGURE4.-Locality of Fitchville Formation-Gardison Limestone sectlon at Rat- section 17 (unsurveyed), T. 9 N, R. 2 E, Cache County. Utah; 5600-foot tlesnake Spur. NE'A, section 1, T. 9 S, R 3 W, Utah County, Utah; contour indicated. Base from Ogden, Urah, U.S. Geological Survey West- 3,800-foot contour indicated; Base from Allen's Ranch and Boulter ern U.S. 1 :250,000 series map. Mountains, Utah, U.S. Geological Survey 7%-minute quadrangle map.

FIGURE3.-Locality of Fitchville Formation-Gardison Limestone secdon in Rock Canyon. Utah, SWM, section 28. T. 6 S, R. 3 E, Utah County. North ~tansbutyMountains, section 31, T. 1 S, R. 6 W, and section 36. Utah; 5,800-foot contour indicated. Base from Bridal Veil Falls, Urah, T. 1 s, R. 7 W, Towle County, Utah; 4,400. and 4.600-foot conrours in- U.S. Geological Survey 7%-minute quadrangle map. dicated. Base from Timpie, Utah, U.S. Geological Survey 15.rninute quad- rangle map. 106 G. J. NEWMAN

Sections were measured and sampled at three locations in central Utah: 360 feet at Rattlesnake Spur in the Tintic district, 260 feet at the North Stansbury Mountains, and 420 feet in Rock Canyon east of Provo. All sections yielded conodonts. The conodonts appear to have withstood dolomitization rea- sonably well although preservation becomes poorer as dolomite crystallinity becomes coarser.

Gardison Limestone The Gardison Formation consists of a 20- to 50-feet-thick lower dolomite bed, a 200- to 250-feet-thick bed of limestone with thin dolomite partings, and an upper massive limestone unit containing abundant thin chert beds. The Gardison Lime- stone is approximately 450 to 500 feet thick throughout its en- tire exposure area. The Gardison Limestone is typically very fossiliferous, con- taining abundant corals, brachiopods, and gastropods. Three sections of Gardison Limestone were measured and sampled: 420 feet at Rattlesnake Spur, 350 feet in the North Stansbury Mountains, and 320 feet in Rock Canyon. All sections yielded at least some conodonts, but, in spite of the abundance of

FIGURE7.-Locality of Joana Limestone section in the Confusion Range, NWM, section 29 (unsurveyed), T. 18 S, R. 16 W, Mlllard County, Utah; 6,600-foot contour ind~cated.Base from Conger Mountain. Utah, U.S. Geological Survey 15-minute quadrangle map.

FIGURE6.-Locality of Joana Limestone sections in the Needle Range, Millard and Beaver Counties, Utah; 7,000-, 8,000-, and 9,000-foot contours in- dicated. Section A, section 26 (unsurveyed), T. 25 S, R. 19 W, produced useful conodont material and is the section described as the Needle Range sccrion in the text; section B, section 27 (unsurveyed), T. 26 S, R. 19 w, FIGURE8.-Locality of Joana Limestone section near Wendover, T. 34 N, R. 70 did not produce good material and is not discussed in the text. Base from E, Elko County, Nevada; 5.000- and 6,000-foor contours indicated. Base Richfield, Utah, U.S. Geological Survey Western U.S. 1:250,000 series from Elko, Nevada, U.S. Geological Survey Western US. 1:250,000 series map. map. CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 107 macrofossils, far fewer conodonts were recovered from the Gar- dison sections than from the immediately underlying Fitchville sections. Sandberg and Gutschick (1978) have explained the low conodont abundances in the Gardison by the rapid rate of sedimentation.

NORTHERN UTAH Lodgepole Limestone The Lodgepole Formation is primarily a carbonate unit, 700 to 800 feet thick, which can be traced over most of Montana and Wyoming, and parts of Idaho, South Dakota, and Utah. Mnor cherty, argillaceous, arenaceous and dolomitic carbonate interbeds occur in most sections. The Lodgepole Limestone is in part fossiliferous, containing an abundant coral-brachiopod- gastropod fauna. The only section of Lodgepole Limestone measured and collected for this study was located at Porcupine Dam, 20 miles south of Logan, Utah, in the Bear River Range. The measured section is 590 feet thick. The section is extremely fossiliferous and yielded by far the most abundant and best preserved con- odonts of any of the sections used in this study.

SYSTEMATIC PALEONTOLOGY From the material collected and processed for the present study, specimens of 27 species and subspecies of conodonts, rep- resenting 11 genera, were recovered. Twenty-three species and subspecies of 7 stratigraphically important genera are described alphabetically and illustrated. The remaining four genera of long-ranging bars and blades: Hibbardella FIGURE9.-Locality of Joana Limestone section near Ely, WM, section 34, T. 17 Hindeodella N, R. 62 E, White Pine County, Nevada; 6,800-foot contour indicated. Ozarkodina Base from Ruth, Nevada, U.S. Geological Survey 7R-minute quadrangle Ne~prioniodus map. These are considered to be stratigraphically unimportant and are not studied. Under occurrence, the following frequen- cies are used, except where noted, in reference to the total number of specimens recovered from the combined sections: Rare-less than 5 Frequent-6 to 25 Common-26 to 50 Abundant-more than 50 All sample numbers listed under occurrence indicate inter- val of the sample above the base of the collected section; for example, L-30 indicates the sample was taken 30 feet above the base of the Logan, Utah, section. Base of section does not nec- essarily correspond to formational boundaries. For formation boundaries refer to figure 11. All figured specimens are reposited with the Department of Geology collections, Brigham Young University (BYU).

Genus ELICTOGNATHUS Cooper, 1939

ELICTOGNATHUS LACERATUS (Branson and Mehl) PI. 3, fig. 18 Description.-Narrow ridge on outer side, narrow ridge to prominent shelf on inner side slightly above aboral edge. Basal cavity elliptical, longitudinally and centrally located, with a sharp keel extending posteriorly and anteriorly. Posterior edge or blade commonly flexed inward. Remarks.-Specimens involved in the present study have a narrow ridge (or only moderate shelf development) on the in- ner side. None possesses the large nodes or buttresses found be- FIGURE10.-Locality of Joana Limestone section near Eureka, NE%,section 19, low the apical dentical of many specimens within the range of T. 19 N, R. 55 E, White Pine County, Nevada; 6,800-foot contour in- dicated. Base from Eureka and Pinto Summit, Nevada. U.S. Geological variability of E. laceratus as defined by Klapper (1966) and Survey I>-minutequadrangle maps. Thompson and Fellows (1970). 108 G.J. NEWMAN

Occurrence. -E. laceratus occurs commonly and is confined to Genus ICRIODUS Branson and Mehl, 1938a the Siphonodella coqieri and lowermost S. obsoleta zones. Speci- mens were recovered from following samples: L-30, L-40, L-50, ICRIODUS cf 1 COSTATUS (Thomas) L-80, and L-100 (Logan); R-200 and R-210 (Rattlesnake Spur); PI. 3, figs. 15, 16 F-70 (North Stansbuty Mountains); A-Base (Needle Range); Description.-Arched platform with prominent inclined pos- and W-24 (Wendover). terior cusp. Nodes of lateral rows aligned with and connected by transverse ridges to nodes in the median row. The large flar- Genus GNATHODUS Pander, 1856 ing basal cavity is widest posteriorly. Remarh. -All recovered specimens of Icriodus cf. I. costatus GNATHODUS DELICATUS Branson and Mehl are very poorly preserved. Invariably, the main cusp, though PI. 3, figs. 13, 14 present, is broken near its base, and the anterior ends of each Description.-Low, broad, asymmetrical cap, ornamented unit are missing. with nodes or rows of nodes. A single prominent row of nodes Occurrence.-Icriodus cf. I. costatus occurs in the costatm Zone. is developed on the narrow inner side, and scattered nodes of Only two specimens were recovered: one from sample R-150 two or more rows of nodes are developed on the wide outer (Rattlesnake Spur) and one from sample F-20 (North Stans- side of the platform. bury Mountains). Remarks-G. delicatus is the only Gnatbodus species recov- ered in present study material, although the Lower Mis- sissippian commonly contains several species of Gnathodus in Genus POLYGNATHUS Hinde. 1879 the Mississippi Valley, Missouri, Texas, and elsewhere in the western United States. POLYGNATHUS COMMUNIS COMMUNIS Branson and Mehl Occurrence. - GnatboduJ delicatus was found at only two local- PI 2. figs. 12. 13. 16, 17 ities. One specimen was recovered from sample T-80 (Sipbono- Description.-The lanceolate or ovate platform is quite vari- de1.l~ obsoleta Zone) in the Eureka section; the other from able in size with the free blade at least as long as the platform. sample R-780 (Polygnathus communis-Spathognatbodus Zone) in Carina is nodose; platform is smooth or may have weakly devel- the Rattlesnake Spur section. oped transverse ridges anteriorly. Shallow troughs are present.

S. OBSOLETA

Q z

FIGURE11.-Age of the Utah-Nevada zones and occurrence within, and correlation between, the eight study sections from which conodonts were recovered. Sec- tions include Logan (A), Rock Canyon (B), Rattlesnake Spur (C), North Stansbury Mountains (D). Needle Range (E), and Confusion Range (F), In Utah; Wendover (G) and Eureka (H) in Nevada. Dashed correlation lines indicate that the zone was not recognized In a particular sectlon. CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 109

The lower surface of the platform has an elliptical to sub- POLYGNATHUS INORNATUS Smsu Branson and Mehl circular pit located at the anterior end of the platform. PI. 2, fig. 3, 4 Remarks. -Polygnathus communis communis is the longest rang- Polygnathus symmetrira Branson , STRAKA, 1968, p. 35, pl. 1, ing platform recovered in this study. It is found almost contin- figs. 11, 13 only. ually in each section, and in many samples, it was the only con- Polygnathus inomatus inomatus Branson and Mehl (sic), odont recovered. Its presence in the youngest samples in each RHODES et al., 1969, p. 186, pl. 10, figs. 4-6; DRUCE, section suggests that none of the measured sections are young- 1969, p. 98, pl. 20, figs. 1-3. er than Osagean. Polygnathus inomata sensu Branson and Mehl, KLAPPER, 1971, Occurme.-Polygnathus communis communis occurs from base p7,pl. 1,figs. 11, 12. to top of each studied section. It is found abundantly in the Description. -Lanceolate platform with short, high free Siphmodella cooperi and Pseudopolygnathus zones but occurs fre- blade. Anterolateral edges of platform strongly upturned. Ca- quently in all other zones. rina and blade virtually straight dividing an almost bilaterally symmetrical platform. Both sides of platform ornamented with POLYGNATHUS PERPLEXUS nodes and transverse ridges. Basal cavity large, circular to ovate, PI. 2, figs. 1, 2 usually with prominent lips, and set in the raised keel. Description.-Compound unit with a free blade about half as Remarks.-See discussion under Polygnatbus inomatus Bran- long as the platform. Platform is broadest medially and tapers son. Few specimens of Polygnatbus inornatus sensu Branson and toward the anterior and posterior ends. Poorly developed carina Mehl were recovered in the present study, but P. inomata Bran- is strongly incurved posteriorly and does not extend to the pos- son was commonly encountered. terior end of the platform. One moderately to strongly devel- Occurreme. -Polygnathus inomatus smu Branson and Mehl oped rostral ridge on either side of the carina. Rostra1 ridges occur rarely in the Siphonoddla cooperi Zone. Samples yielding angle toward but do not intersect carina. Oval surface orna- specimens were R-200 and R-210 (Rattlesnake Spur); A-Base mented with randomly arranged nodes. Aboral surface smooth (Needle Range). except for prominent raised keel which is highest at anterior and posterior ends. Basal cavity is an indistinct slit located within the keel in the central part of the platform. POLYGNATHUS LONGIPOSTICUS Branson and Mehl PI. 2, figs. 9, 10, 14, 15 Remarks. -Specimens included in Polygnathus perplexus show moderate variability of rostral ridge development and size and Description. -Platform may not reach posterior end of ele- ment. Anterolateral margins of platform upturned to about the abundance of nodose ornamentation. level of the carina. Platform margins transversely ridged and Occurrence. -Specimens assigned to Polygnathus petplexus oc- cur frequently in the Bipathodus costatm zone. Samples yielding usually nearly straight. The basal cavity is large, circular to ovate, and set within the platform. specimens include: F-Base, F-10, and F-20 (North Stansbury), and R-60, R-70, and R-80 (Rattlesnake Spur). Remarks. -Because of the transition between Polygnathus longiposticus and P. ~ymmetricus,assignment of some specimens POLYGNATHUS INORNATUS Branson to one species or the other is arbitrary. High degree of up- turning of the anterolateral margins and extension of the blade PI. 2, figs. 7, 8 beyond the posterior end of the platform were considered diag- Description.-Lanceolate platform with a short, high free nostic of P. longiposticus. blade. Anterolateral edges of platform strongly upturned. Ca- rina sinuous posteriorly and may be strongly incurved. Plat- Occurrence. -Polygnathus longiposticus occurs commonly in the form asvmmetrical with a distinct sinus or constriction near its Siphmodella cooperi Zone. Samples yielding specimens were L-30 posterior lateral terminations. Both sides of platform orna- and L-40 (Logan); R-200 and R-210 (Rattlesnake Spur); F-70 mented with nodes and transverse ridges. Basal cavity relatively (North Stansbury); and W-24 (Wendover). large, circular to ovate, usually with prominent lips, and set in the prominent raised keel. POLYGNATHUS EXTRALOBATUS Schafer Remarks. -Klapper (1971) discussed the problem concerning PI. 2, figs. 11, 18 the simultaneously published Polygnathus inomatus types of [email protected] platform with greatly expanded Branson, 1934, and Branson and Mehl, 1934b. He recognized outer side, strongly incurved platform with the carina not two form species and designated the specimen illustrated by E. reaching the posterior end. Posteriorly to the carina the plat- R. Branson (1934, pl. 25, fig. 8) as lectotype of P. inomatus. form is crossed by oblique, transverse ridges. Ridges are oblique Polygnathus inomatus E. R. Branson is distinguished from P, in- to carina on the inner side of the central portion of the plat- omatza of Branson and Mehl as follows: the former has an form. Pit elliptical with lips. asymmetrical platform, with a sinus in the posterior outer mar- Remarks.-In the present study Polygnathus extralobatus fre- gn and a sinuous or incurved posterior carina, whereas P. in- quently occurs with P. semicostatus, which is similar. Because of omatus Branson and Mehl has a virtually straight blade and ca- effects of dolomitization of the enclosing rocks, carinal and rina that divide an almost bilaterally. symmetrical . platform. transverse ridge detail is often obscured. In such cases, the (For a complete discussion of the Polygnathus inomatus broader, more posteriorly rounded specimens are placed with P. problem see Klapper 1971, p. 6-7). extralobatus; the more elongate specimens with pointed posteri- Occurrence. -Polygnathus inornatus Branson occurs commonly or ends, with P. semicostatus. in samples from the Siphonodella cooperi Zone. Specimens were Occurrence. -Polygnatbus extralobatus occurs frequently with- recovered from samples L-30 and L-40 (Logan); F-70 (North in the Bipathodus costatm Zone. Samples yielding specimens Stansbury) ; A-Base (Needle Range) ; T-Base (Eureka) ; and W- were: N-20 (Rock Canyon); F-50 (North Stansbury); R-70, R- 24 (Wendover). 110, and R-150 (Rattlesnake Spur). 110 G J NEWMAN

POLYGNATHUS SEMICOSTATUS Branson and Mehl mens. Large basal cavity subcircular, thick lipped, with short PI 2, figs 5, 6 points posteriorly and anteriorly within narrow keel Description.-Conodont with short blade and long, narrow Remarks.-Forms included as Pseudopolygnathus cf. P. multz- to fairly wide and highly arched platform. Platform constricted striatus in this study appear to be largely immature. They occur medially and extends to a sharp point posteriorly. High, promi- with P, primus and may be juvenlle forms of P, primus. How- nent carina or~ginatesnear the constricted central portion of ever, the overall platform shape, and espec~allythe shape of the platform and passes anteriorly Into the blade. Posterior to the basal cavity, is very simllar to forms of P. multistnatus 11lus- carina, strong transverse ridges cross the width of the platform. crated by Thompson (1967, pl. 4, figs. 15, 16, 19, 20). Aboral surface comes to a sharp ridge w~ththe keel indistinct Occurrence. -Forms ass~gnableto Pseudopolygnathus cf. P. mul- as apex of ridge. Elliptical pit, wlth poorly developed lips, set in tl~tPiatusoccur frequently with P. pmus in the Pseud?po~g- keel at anterior end of platform. nathus Zone. Samples yielding specimens include L-610 (Lo- Occurrence. -Polygnathus sernzcostatus occurs abundantly al- gan); F-600 and F-610 (North Stansbury); A-445 and A-450 most cont~nuouslythrough the Spathognathodus costatus Zone. (Needle Range); and C-270, C-280, and C-290 (Confusion Samples yielding specimens include F-Base to F-50 (North Range). Stansbury) and R-Base to R-100 (Rattlesnake Spur). PSEUDOPOLYGNATHUS TRIANGULUS TRIANGULUS Voges Genus PSEUDOPOLYGNATHUS Branson and Mehl, 1934 PI. 3, figs 11, 12 Description. -Nearly symmetr~caland subtriangular platform PSEUDOPOLYGNATHUS MARGINATUS Branson and Mehl anterior marglns nearly perpendicular to carina Carina and keel PI 3, figs 7, 8, 9, 10 slightly incurved, platform ornamented by numerous small Descnptim.-Lanceolate platform tapering to a sharp point closely spaced transverse ridges. Basal cavity small, ovate, and near or at the posterior end of strongly nodose canna. Platform set in keel. equally developed on both sides of carina and bears weak to Remarks.-The small basal cavity and fine ornamentation of strong transverse ridges. Prominent raised keel present Pseudopolygnathus tnangulus tnangulus are more simllar to throughout length of platform except where interrupted by polygnathid forms than to most pseudopolygnathids. How- basal cavity. Wide basal cavity nearly symmetrical with thlck, ever, Voges (1959, p 295-296, text-fig. 5) presents phylogenetic flaring lips. evidence relatlng P. trzangulus triangulus to P. trzangulas Remarks. -Several growth stages of Pseudopolygnathus margz- znaequalzs, establishing P. triangulus trzangulus as a true natm are present in the study material Immature forms have pseudopolygnathid. basal cavities of much the same size and shape as mature specl- . - mens but have very small platforms with only very weak trans- Occurrence.-Pseudopolygnathus triangulus triangulus was re- verse r~dgesor nodose ornamentation. covered from only two samples, both from the Sphmo&lla coop- 0ccu&ce. -~seud?po~~nathusmarginatu occurs in the Sqb- eri Zone. P. tnangulus tnangulus occurs frequently in sample L- mo&lla coopen Zone. Only sample L-30 (Logan) yielded mate- 30 (Logan) and rarely In sample F-70 (North Stansbury) rial assignable to P. margznatus. Genus SIPHONODELLA Branson and Mehl, 1944 PSEUDOPOLYGNATHUS PRIMUS Branson and Mehl PI 3, figs 1,2, 3,4 SIPHONODELLA COOPER1 Hass PI 1. figs 3, 4 Describtion.1 -Asvmmetr~cal ~latformwith lateral lobe devel- oped on one side (right or left) only R~ghtside of platform Description.-Nodes on inner s~deof platform and strong developed farther anteriorly. Ornamented w~thcoarse and ir- transverse ridges on outer s~de.Two or three rostral ridges pres- regular transverse r~dgesor, in immature specimens, with single ent; longest one on outer platform terminating poster~orlyat nodes on each ade of platform. Basal cavity is large and asym- outer margln of platform or forming that margin metrical and does not extend to platform margins In mature Remarks. -Siphmodella coopen is simllar to and trans~tional specles. with S. quadruplicata. Specimens recovered durlng the present Remarks. -In the present study forms assignable to Pseudopo- study show all stages of development between the two species. lygnathus primus occur in rocks as young as latest Kind- Those forms where the longest lateral ridge on the outer plat- erhookian or Valmeyeran. Many of these forms occupy the stra- form either terminates poster~orly at the outer margin or be- tigraphic interval usually occupied by P. multistriatus in the comes that margin are considered to be S. coopen. In S. quad- m~dcontinentarea. Many forms assigned to P, primus in th~s ruplicata the longest rostral ridge on the outer platform study may be transitional with P. multistriatus. terminates posteriorly In the region above the basal cavity and Occurwnce. -In the studied faunas P~eudopolygnathu~primas does not reach the lateral margln. occurs commonly only in the Pseudopolygnathus Zone. Samples In agreement with Klapper (1971, p. 10) the division of S. yieldlng specimens include L-610 (Logan), F-600 and F-610 cooperi into subspecies (Thompson and Fellows, 1970, p (North Stansbury); A-445 and A-450 (Needle Range); and C- 104-105) IS not considered valid as illustrated forms can be re- 270, C-280, and C-230 (Confusion Range). ferred to either S. obsoleta or S. rsostzcha (see synonomies) A zone of probable equivalence to the Siphmo&lla coopen hassz sub- PSEUDOPOLYGNATHUS cf P MULTISTRIATUS Mehl and Thomas zone of Thompson and Fellows (1970) was recognized In the PI 3, figs 5, 6 present study sections, but all siphonodellids were referable to Description. -Elongate, gently convex, doubly tapering plat- S. obsoleta. form extends farther anteriorly on the right side. Blade, short, Occurrence. -Siphono&lla coopen is the most abundant specles carina low and nodose. Both sides of platform ornamented recovered durlng the present study It is found abundantly over with coarse transverse ridges or single nodes in immature speci- a 10-to-20-foot interval near the base of SIX of the studied CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 111 sections. Its presence defines the Siphonodella cooperi Zone. Sam- SIPHONODELLA OBSOLETA Hass ples from which specimens were recovered include L-30 and L- PI. 1, figs. 5, 6 40 (Logan); R-200 and R-210 (Rattlesnake Spur); F-70 (North Description.-Relatively long narrow platform with two to Stansbury); A-Base (Needle Range); W-24 (Wendover); and four rostral ridges. Long rostral ridge extends to near posterior T-Base (Eureka). end of outer platform. Inner platform nodose, outer platform weakly ornamented or smooth between the long rostral ridge SIPHONODELLA CRENULATA (Cooper) and carina. PI. 1, figs. 9, 10 Remarks. -Above the occurrence of all other siphonodellids Description. -Markedly asymmetrical platform; outer, strong- in the studied sections, one form of S$bonodella persists. This ly convex, margin may have sharp angular bend at midlength. form is the same Siphonodella that was designated S. cooperi bassi Two, or rarely three, short rostral ridges present. Mature speci- by Thompson and Fellows (1970, p. 104-105, pl. 6, figs. 2, 4). mens typically ornamented with transverse ridges on the outer In agreement with Klapper (1971, p. 12) these forms are con- platform and nodes on inner platform. sidered to be S. obsoleta. In the present study area, the per- sistence of S. obsoleta beyond the range of all other siphonodel- Remarks. -Two mature specimens of Siphonodella crenulata lids defines the SiphonodeIla obsoleta Zone. were recovered during the study. The remaining specimens Occurrence. -Siphmodella obsoleta occurs occasionally in the were small, immature forms with the typical S, crenulata plat- Siphonodela cooperi Zone in samples L-30 (Logan), R-210 (Rat- form outline but either devoid of oral ornamentation or only tlesnake Spur), F-70 (North Stansbury), A-Base (Needle faintly nodose. Range), W-24 (Wendover), and T-Base (Eureka). S. obsoleta oc- Occurrence.-Eight specimens that are definitely Siphonodella curs abundantly in the Siphonodella obsoleta Zone. Samples yield- crenulata were recovered from sample L-30 (Logan). Fragments ing specimens include: L-40 to L-240 (Logan); R-220 to R-240 of what may be S. crenulata were noted in samples F-70 (North (Rattlesnake Spur); C-Base and C-5 (Confusion Range); and T- Stansbury) and T-Base (Eureka). All specimens are from the 25 to T-80 (Eureka). S@onodella cooperi Zone. SIPHONODELLA QUADRUPLICATA (Branson and Mehl) SIPHONODELLA cf. S. ISOSTICHA (Cooper) PI. 1, figs. 11, 12 PI. 1, figs. 1, 2 Description. -Posterior termination of the innermost rostral Description. -Representative specimens have posterior termi- ridge on the outer platform is adjacent to the position where nation of the longest rostral ridge on the outer platform adja- the carina begins to incurve and between the margin and the cent to the position where the carina begins to incurve and carina. Number of rostral ridges varies from three to five. Out- midway between the carina and margin. Long rostral ridge on er platform ornamented with transverse ridges, inner platform inner side terminates at a comparable position. Posterior plat- is nodose. form weakly nodose with somewhat stronger nodes on the in- Remarks.-The distinction between Siphonodella quad- ner side. ruplicata and S. cooperi is based on the position of termination Remarks.-Klapper (1971, p. 10, 12), in a restudy of the of the innermost rostral ridge on the outer platform, as empha- holotype of Siphonoddla isosticha, recognized a difference in the sized in the diagnoses of the respective species. This division is position of posterior termination of the longest outer rostral highly artificial and within the present study material, forms ridge of specimens assigned to S. isosticha. The longest outer representing a complete transition between the two species rostral ridge of the holotype terminates at the outer margin. were recovered. Specimens where the longest outer ridge terminates on the Occurrence. -Siphonodela quadmplicata occurs frequently platform rather than at the outer margin are referred to as S, cf. within the Siphonodella cooperi Zone. Samples yielding specimens S. isosticha. include: L-30 (Logan); R-200 and R-210 (Rattlesnake Spur); F- Occurrence.-Siphonodella cf. S. isosticha occurs frequently in 70 (North Stansbury); A-Base (Needle Range); W-24 (Wen- samples L-30 (Logan) and rarely in sample A-Base (Needle dover) ; and T-Base (Eureka). Range) and is confined to the Siphonodella cooperi Zone. BISPATHODUS (Mullet, 1962) SIPHONODELLA LOBATA (Branson and Mehl) BISPATHODUS ACULEATUS (Branson and Mehl) PI. 1, figs. 7, 8 PI. 3, fig. 19 Description. -Outer lateral lobe present. Transverse ridges or- Description.-Lateral denticles developed on inner side of nament both sides of platform. Rostrum well developed. Keel blade in the atypical for SiphonodelIa, raised and continuous throughout en- region of basal cavity. Development of lateral den- ticles does not reach posterior tip. Unit nearly straight to tire length of platform, interrupted only by small, lipped, basal slightly curved. Basal cavity located at mid-length, nearly circu- cavity. Secondary keel beneath outer lateral lobe joins main keel lar in shape, and wide. at basal cavity. Remarks. -Lateral denticles of Bispathodus aculeatus are usual- Remarks.-The prominent outer lobe and continuous raised ly joined to the denticles of the main row by transverse ridges. keel distinguish Siphonodella lobata from other siphonodellids. Number of lateral denticles variable but specimens from the The keel of S, lobata is similar to that of the polygnathids; present study usually have 4 lateral denticles. B. aculeatus is a however, the well-developed rostrum and very small basal cavity slightly more robust form than most spathognathodids. are typically siphonodellid. Occurrence. -Bispathodus aculeatus occurs frequently in the Occurrence.-Only two specimens of Siphonodella lobata were B. costatus Zone. Samples yielding specimens include: N-20 recovered. Both specimens occurred in sample L-30 (Logan) (Rock Canyon); R-90 (Rattlesnake Spur); and F-50 (North within the Siphonadella cooperi Zone. Stansbury).

CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA Langenham, R L . 1960, Early and M~ddleMlsslss~pp~an strat~graphy of the Ely Sandberg, C A, Mapel, W J, and Huddle, J W, 1967, Age and reg~onalslg- area. In Gu~debookro the geology of east-central Nevada Intermounraln nlficance of basal part of Mlll~ganFormat~on, Lost Rlver Range, Idaho Assoc~at~onof Petroleum Geologists Gu~debook,p 63-71 In Geolog~calSurvey Research, chapter C , US Geolog~calSurvey Profes- hndgren, W , and Loughlin, G F, 1919, Geology and ore depos~rsof the Tlnt- slonal Paper 575-C, p C127-C131 IC mlnlng d~srncr,Utah US Geologlcal Survey Profess~onalPaper 107. Sandberg, C. A, and Poole, F G, 1970. Conodonr b~osrrar~graphyand age of 282p West Range Llmestone and Pllot Shale ar Bactnan Mountam, Pahranagat Lndstrom, M , 1964, Conodonts Elsev~er,Amsterdam, 196p Range, Nevada Geolog~calSoc~ery of Amer~caAbstracts w~thPrograms, Manzon~,M, 1966, Conodont~ Neodevonlc~ed Eocarbonifen al Monte Zer- v 2, no 2, p 139 mula (Alp1 Carn~che) G~ornalede Geolog~a,v 33, p 461-88 , 1977, Conodont b~ostrat~graphyand depos~r~onalcomplexes of Marrhews, S C , 1969. Two conodonr faunas from the Lower Carbon~ferousof Upper Devon~an craton~c-plarform and conrlnental-shelf rocks In rhe Chudle~gh,south Devon Palaeontology, v 12, 276-380 western Un~redStares Wesrern North Amer~ca Devon~an,Unlvers~ty of Merr~am,C W, 1963, Paleozoic rocks of the Antelope Valley, Eureka and Nye Cal~forn~a,Rlvers~de, Campus Museum Contrlbut~onno 4, p 144-82 Count~es.Nevada U S Geologlcal Survey Profess~onalPaper 432, p 12, Sando, W J , Dutro, J T , Jr , and Gere, W C , 1959, Brazer Dolom~te(MIS- 42, 56, 58 slsslpp~an)Randolph Quadrangle, northeast Urah Amencan Assoc~ar~on Morns, H T , and Lovenng, T S , 1961, Strat~graphyof the Easr Tlntlc Moun- of Petroleum Geologlcal Bulletin, v 43, p 2741-69 rams, Urah US Geolog~calSurvey Profess~onalPaper 361, 145p Schonlaub, H P , 1969, Conodonten aus dem Oberdevon und Unterkarbon des Kronhofgrabens (Karnlsche Alpcn, Osterre~ch) Austna, Geolog~sche Mound, M C , 1968, Upper Devon~anconodonrs from southern Alberta Jour- Bundesansralt, Jahrbuch, v 112, p 321-54 nal of Paleontology, v 42, p 444-524 Seddon, G, 1970, Pre-Chappel conodonts of rhe Llano Reg~on.Texas Texas Mullet, K J, 1962, Zur sysremar~schen Elntellung der Conodontophor~da Un~vers~ty,Austin, Bureau of Econom~c Geology, Report of In- Palaontolog~scheZatschnfr, v 36, p 109-17 vestlgatlons 68, 130p Nolan, T B , Mernam, C W , and Wlll~ams,J S , 1956, The strat~graph~csec- Sloss, L L, and Hamblln, R H , 1942, Strat~graphyand ~nsolubleres~dues of tion In the vlcln~tyof Eureka, Nevada US Geolog~cal Survey Profes- Mad~sonGroup (Mlsslss~ppian)of Monrana Amer~canAssoc~at~on of Pe- sional Paper 276, 77p troleum Geolog~srs,Bullerln 26, p 2135-69 Pander, C H , 1856, Monograph~eder fossllen Flsche des sllunschen systems der Spassov, H , Srojanov~c-Kuzenko,S, and Pallc, V, 1968, Les nouveaux resultars Russ~sch-balr~schenGouvernemenrs Buchdrucker der K Akadem~eder obtenus par l'trude des Conodontes PalPozo~quesde la Serb~edu nord- Wlssenschafren, St Petersburg, 91p, 8 pls ouest Inst~rutdes Recherches Gkolog~queser Gkophys~ques,v 26. Peale, A C, 1893, The Paleozo~csccrlon In the vlclnity of Three Forks, Mon- 153-66 tana U S Geologlcal Survey Bulletln 110, 56p Spencer, A C, 1917, The geology and ore depos~tsof Ely, Nevada US Geo- P~erce,R W, 1969, Ultrastructure and b~ostrat~graphyof the conodonts of the log~calSurvey Professional Paper 96, 189p Monte Cnsto Group, Arrow Canyon Range, Clark County, Nevada Srraka, J J, 1968, Conodont zonatlon of the Klnderhooklan Series, Washing. PhD dlssertatlon, Un~vers~tyof Illlno~s,Champa~gn, 118 p (Dlsserr ton County, Iowa Unlvers~ryof Iowa Stud~esIn Natural History, v 21, Abs Inrernat. v 31, Ser B, SCI and Eng , p 761B-762B, 1970) 71P Plerce, R W, and Langenhe~m,R L, Jr, 1974, Platform conodonrs of rhe Thomas, L A, 1949, Devon~an-M~ss~ss~pp~anformat~ons of southeast Iowa Monte Cnsto Group, Mlsslsslpplan, Arrow Canyon Range, Clark County, Geologlcal Soctety of Amer~caBullerln 60, p 403-38 Nevada Journal of Paleontology, v 48, p 149-69 Thompson, T L, 1967, Conodont zonatlon of lower Osagean rocks (Lower Plnney, R I. 1965, A prel~mlnarysurvey of Mlsslsslpp~an b~ostrar~graphy(con- Mlsslss~pp~an)of sourhwestern Mlssoun Mlssoun Dlvls~onof Geologlcal odonts) In the Oqulrrh Basln of central Utah Ph D dlsserrat~on,Unlver- Survey and Warer Resources Report of Invesc~gat~ons39, 88p sity of W~xonsln,Madison Thompson, T L , and Fellows, L D , 1970, Srrat~graphyand conodont b~ostrat~- Rexroad, C B, 1969, Conodonrs from the Jacobs Chapel bed (Mlsslss~pp~an)of graphy of KinderhookIan and Osagean (Lower Mlsslss~pp~an)rocks of the New Albany Shale in southern Ind~ana Ind~anaGeologlcal Survey southwestern Mlssoun and adjacent areas Mlssour~D~v~s~on of Geologl- Bullerln 41, 55p, 9 pls cal Survey and Warer Resources Report of Invesrlgatlons 45. 263p Rexroad, C B, and Scott, A J, 1964, Conodont zones In the Rockford Lime- Ulr~ch,E 0,and Bassler, R S , 1926, A class~ficationof the roorhl~kefossils, stone and the lower part of the New Prov~denceShale (Mlsslss~pp~an)In conodonts, w~thdescr~pt~ons of Amer~can Devon~an and M~sslss~pp~an lnd~anaInd~ana Geologlcal Survey Bulletln 30 specles US Nat~onalMuseum Proceedings, v 68. 63p, 11 PIS Rhodes, F H T , Ausrln, R L , and Druce, E C , 1969, Brit~shAvonian (Car- Voges, A, 1959, Conodonren aus dem Unterkarbon I und I1 ((Gartendorfio und bon~ferous)conodont faunas and the~rvalue In local and lntercontlnental Penqlus-Srufe) des Sauerlandes Palaonrolog~sche Ze~rschnfte, v 33, p correlar~on Bnr~shMuseum (Natural H~srory)Bullet~n, Geolog~cal Sup- 226-314, pls 33-35 plemenr 5, 313p, 30 pls Youngqutst, W, and Patrerson, S H , 1949, Conodonts from the Lower MIS- R~chardson, G B, 1913, The Paleozo~csectlon In northern Utah Amer~can slsslpplan Prospect Hill Sandstone of Iowa Journal of Paleontology, v Joumal of Sc~ence,4th senes, v 36. p 406-16 23, p 57-73, pls 15-17 Sandberg, C. A, and Gursch~ck,R C , 1969, Strat~graphyand conodont zona- Zle~ler,W , 1960, In Kronberg. P, P~l~er,A, and Scherp, A, Spuren alrvar- rlon of type Leatham Formarlon (Devon~anand Mlsslss~pptan),Bear RIV- - iscischer Bewegungen ~m-nordostllchenTell des ~helnlschenSch~eferge- er Range, Urah Geolog~calSoc~ety of Amer~ca(Rocky Mountam Sec- b~rgesFortschnrre In der Geolog~evon Rhelnland und Westfalen, v 3, p t~on),Abstracts w~rhPrograms, v 1, pr 5, p 70-71 1-46, pls 1-7 , 1978, B~ostrat~gnphicgu~de ro Upper Devon~an and MIS- , 1962a, Taxlonomie und Phylogen~e Oberdevonlscher Con- slsslpplan rocks along rhe Wasatch Front and Cordilleran Hlngellne, odonten und ~hresrrat~graph~sche Bedeutung Hesslsches Landesamr fur Utah US Geologlcal Survey, Open-File Report 78-351, 52 p Bodenforschung, Abhandlungen, Heft 38, 166p Sandberg, C A, and Klapper, G , 1967, Srrat~gtaphy,age, and paleotecron~cslg- , 1962b, Die Conodonren aus den Gerollen des Zechste~nkong. nificance of the Cottonwood Canyon Member of the Mad~sonLlmestone lomerates von Rossenray (sudwesrl~ch Rhe~nberg/N~ederrhein)mlt der In Wyomlng and Montana US Geolog~calSurvey Bulletin 1251-B, p Beschrelbung elnlger neuer Conodontenformen Fortschntte In der Geolo- B1-B70 gle von Rhelnland und Westfalen, v 6, p 391-405 (preprlnt 1960) 114 G. J. NEWMAN

TABLE 1 D~STR~BUTIONOF CONODONTS IN THE LOGANSECTION THE610-FOOT SECTION WAS MEASURED IN 10.FOOT INTERVALS. THESE29 INTERVALS YIELDED CONODONT MATERIAL. I5 INTERVALS WERE SAMPLED BUT BARREN, AND 18 INTERVALS WERE COVERED AND NOT SAMPLED.

I.eo,ho,,, 1 ,,,lF,.,,,,1, 1 ,,, FORMATION Fm : I',,,,,,,,, ' CONODOHT ZONES (~~h~~~d~lb~cooprn ~~~~l~f~r~~~~lcla ,21,q,,l,~~,, ~'~~~,,~,,l','l~~,'"'~"'~ 1 ,,,,,, 1,. , ",\~,,l,",,,,,, ~ :

30 46 M 60 70 80 90 I00 110 120 130 140 0'50 /60 I70 I80 190 210 220 240 259 345 jb0 440 460 590 6% 610

t.l~rlo~nalhucIn,em!u~ 29 1 I

PalygnnlhuyI nmmun~c 23 10 3 I 222 11 4Pll/l// 2 I 7

P~l~~~~th~,.dnumoluc Rmncon I1

Polygnalhuc ~nornolu.Hmnqon K \I~hl 5 I

Polwnolhu~long~po~lw,~~ 30 6 I 1

Polyennrhuc cprl frr codrl#rmcnn!e 3 2 1 I

P,~"d"~"l"~~~lh~..mnrg,,ml". I2

Ps~~~dopolygmolhv~111'. mulld*lrulur 2 2

Plludopol,"~na,hucpnmu. 2 I P~~~d~~~l,~~~~lh~~Lmnpulur lnnn+uluv N

51phonodrlh roopen 169 8

Slphonod~llarmnulolo 18 I

Stphonodsllo rl \ tmo.,,, hn 462 S,phooodello lobolo 6

Slphunodrllo ob>nlrla 60367 1 15 3 5 ///I21592 2 I I

.Slphunodrlla yuodruplllorn 6

Slphonnd.llo sprrw. lndelrrmlnole 47 I3 2 2

Spolhognalhodul cmsnd~nr~lu. 16 2 I 2 I I36 2 313 I 3

TABLE 2 DISTRIBUTIONOF CONODONTS IN THE ROCKCANYON SECTION THE740-FOOT SECTION WAS MEASURED IN 10-FOOT INTERVALS THESE9-SAMPLE INTERVALS YIELDED CONODONTS, 54 INTERVALS WERE SAMPLED BlJT BARREN, AND 8 INTERVALS WERE COVERED AND NOT SAMPLED.

FORMATION P~IOIIII!I~fnl ,.<~rdfv,o1 %

CONODONT ZONES \l~~~~~~gr~c~~~~~~cl~~~~~~vlm~r,y~,;::;;,, ~~~~~'~~~~~,,,,,, P~~~,,~l~~p~~l~~nn~hrfi~

20 42% 593 X)M) 630 650 660 65% 700

~~'uh~~~#h~,~,om,n,lolc 2 1/52 6

P"l"#no,h,,r ,nornn,,,c Hruocnr, 6 ll"ll1 I

I'"l"~"'ll,,,c obllqlllror,o,l,c 5 Ci C P,,l"~no,h,,c cpr,,r. lndel?rrnloo,e P Y \~,l",hr,gnn,hnrl,.. "9 .l~",,rr I * \plho~n"lh"duc rm.ctdm,n,uc 21021323

TABLE 3 DISTRIBUTIONOF CONODONTS IN THE RATTLESNAKESPUR SECTION THE780-FOOT SECTION WAS MEASURED IN 10-FOOT INTERVALS. THESE25-SAMPLE INTERVALS YIEI-DED CONODONTS, 26 INTERVALS WERE SAMPLED BIJT BARREN, AND 28 INTERVAlS WERE COVERED AND NOT SAMPLED.

FORMATION hlrl$l rdIr, tn, l.iinl,

CONOOONT ZONES 5polh,zgnolliod~i~I o~tol,,.

U4.F W 20 JO L) 60 70 80 92 110 I20 W /<0 I50 200 210 220 230 240 360 710 730 750 760 770 780 CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 115

TABLE 4 DISTRIBWTIONOF CONODONTS IN THE NORTHSTANSBURY MOUNTAINS SECTION THE650-FOOT SECTION WAS SAMPLED IN 10-FOOT INTERVALS. THESE12-SAMPLE INTERVALS YIELDED CONODONTS, 21 INTERVALS WERE SAMPLED BUT BARREN, AND 33 INTERVALS WERE COVERED AND NOT SAMPLED.

FORMATION F~lrhvdlePm. Carduon 1.r ; PoIybn.rhur ralnm"nu - : CONODONT ZONES Sptho~mlhodur roslolvi SyhonudeUa roopcn P,rudopd"pl.Lhul I ; : Splhq~lhoduarmmdmtntus :

8A.W I0 ZO 50 70 a0 405 560 570 &W 590 603 6/11

Ellrl"gnolh"l lorrrotv. N

Polyg"~lhu~rommunm 7 52 31 227414 H 16

PoIyporh~smornatu$ Rmnmn & lrhl 4

Poly,q""thul longpoallrua 9

P~lyp~rhuarmnub~u~ 32 9

P0lwa,hu. "blqvi, o.101". 2

Pnl*.nolhua ~#nuc'orlalur 561

POI^^"^,^". .pear# ,nd.,rmlnolr 2 I 3 P,l"d"pol"~nothua 11 P. multul,,.,". P>,"d~~~l~~~.lh"~IM~"~".Lrulqulu. 4

Saphonudrlb rnoprn 67

lphonodrUa obrulrta I8

.Szphonodee ape~wstndeterm,mlr I6

.splhognalhodur o

Spalhqmlhodu. rm~~drnlalu~ I24 11 2 825 33

TABLE 5 D~STRIBUTION OF CONODONTS IN THE NEEDLERANGE SECTION THE610-FOOT SECTION WAS MEASURED IN 10-FOOT INTERVALS. THESE8 INTERVAIS YIELDED CONODONTS, 45 INTERVALS WERE SAMPLED BUT BARREN, AND 9 INTERVALS WERE COVERED AND NOT SAMPLED.

FORMATION jmna 1%

CONODONT ZONES ~lphnnnde~aroopert i ,s~~XX~a~n~n~u8 i ~~~~d~~~lygnolhu$

a45f m 409 415 4W 445 IM

Ebrl#,~nn,hu" lorsmtua 2

P01~gn~ll1~.romm"n!$ 7 53523ZJ5

l~olrg~~lhusdeBcnLuB8 2

Polygnarh~~tnomolus Hm~vn I

Pol."gnalh". ,no,".l"" Hmnson R llrhl 2

PnIygm,hu. l"nppo>ltc.ur 2

Po(rlnotl~~~SP~ZPS ~ndolemtnole I

P"~"d<,p"l"~"~,h",,L P. ~"I,,s,,~~"s 3 2

slphonadrUa roopert 4 .S~~h~n~d~lhc.1 h. auusl~ha I

S,phunndrUa ob""lr1. 3

Slphonodrlln quadnrpllrala 2

Slpllnnod.Ua ,prc,r" lndrlrrmlna,~ 3

.Spa~ho~norhnduqrmwdenuru* I 42ZIPJI

TABLE 6 D~STRIBUTION OF CONODONTSIN THE CONFUSION ~NGESECTION THE290-FOOT SECTION WAS MEASURED IN >-FOOT INTERVALS. THESE15 SAMPLE INTERVALS YIELDED CONODONTS, 31 INTERVALS WERE SAMPLED BUT BARREN, AND 14 INTERVAIS WERE COVERED AND NOT SAMPLED.

FORMATION Jmm Lr

CONODONT ZONES Lphonodeh obsolelo : Polygnolhu~lammunu - Spolhognalhnlu~rmar~d?nlolus j R~udupul,gnolhu~

B~O 5 30 I= DO ZJS 240 I"AS m a5 270 275 m m m

P0Iy~lhu~communi( 12319 24N20H2 9

Pdy#~lhunI~O~~LYI Bnnaon & Mehl 6

Plrudopolygmlhua cJ P. muUrsl~lus I 2 6 3

Pl..d.p.ly~'.,h'* pnmu, 1 2

SqhonodrU. ob~okla I

Sqhonodrh species mdelermmah I /

Splh~mlhodu8emu~dmlalu# / / I/ /8633/2 116 G.J. NEWMAN

TABLE 7 TABLE 8 DISTRIBUTIONOF CONODONTS IN THE WENDOVERSECTION DISTRIBUT~ONOF CONODONTS IN THE EUREKA SECTION THE24.~00~ SECTION WAS MEASURED IN 2-FOOT INTERVALS. SAMPLEINTERVAL THEABOVE 4 SAMPLES REPRESENT THE ONLY OUTCROPS IN THE 80-FEET 24 YIELDED CONOWNTS, 9 INTERVALS WERE SAMPLED BUT BARREN, AND 3 SECTION. THEREMAINDER OF THE SECTION WAS COVERED AND NOT SAMPLED INTERVALS WERE COVERED AND NOT SAMPLED.

FORMATION Joono I r FORMATION Jmna 1.3.

51phanodeUa ruoperl S~phonodrUaobwlelo CONODONT ZONES F,phnosdrlla coupor8 CONOUOHT ZONES /

@AE 2 4 6 8 I0 1 I6 18 24 0%&,

t.L~lo#nulhu.lv<~mluv I EBC~~~~O~~USlnromrur 2

Pnlyg~lhllrrommun,r 3 I.nnlhod8,. ~PIIIOII#- I

Polypalhuq mumo,us Rmn...n 3 Iblr~nolhar,s,,,,,,un,r 5 2

P0lygmlhu3 ~nornolulHmnron ir Ilehl I%l.pnolh~n8aurnnla. Hmn~,)a 1 c Polrgnolh"> lon~,porl,r.r Ibl>~6nolhlrrtosrnnlu~ Hrnn~~m d llrlil I R /I 6 1'"lrpnalhur cpp,,r. i"de,?nr,,"o,? I Poly~nolhuarp<,#. ,nd~lrmlaole B Slphon0dello roopen 9 .51ph0!?1d~Ua,,mp#ri I6

Slphonodellauhaolrlo 3 \lpllsosdl~llu,,hwlrlu N 326

.SrphonudrNo quadnrpbroto 4 \,yrhsolzd*lln ql,ad~pl,lnla 2

.Slphonodelln >perter tndrlrrm~mle I3 \,pl,o"ud~Uocpr, err

Splhag~lhodul

EXPLANATION OF PLATE 1 All figures are unretouched photographs of coated specimens. Figures 1, 2.-Siphonodella cf S isorticha (Cooper) Lodgepole Lrnestone, Logan (L-30). Oral and aboral views, hyporype, BYU-1914, X30. 3.4.-Siphonoddla cooper; Hass. Lodgepole Limestone, Logdn (L-30). Oral and aboral views, hypotype, BYU-1912, X35 .5,6.-SiphonodeIIa obsoleta Hass. I, Fitchville Formation, Rattlesnake Spur (R-200). Oral view, hyporype, BYU-1909, X35. 6, Lodgepole Limestone, Logan (L-170) Oral view, hypotype, BYU-1910, X35. 7,8.-S~phonodellalobafa (Branson and Mehl). Lodgepole Limestone, Logan (L-30). Oral and aboral views, hypotype, BYU- 1915, X2T ~,Io.-Siphonoddlacrenulata (Cooper). Lodgepole Limestone, Logan (L-30). Oral and aboral views, hypotype, BYU-1913. X25 11.12.-SphonodeIIa pad- rujdicafa (Branson and Mehl). Lodgepole Limestone, Logan (L-30). Oral and aboral views, hyporype, BYU-19122, X35. CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 117 G J NEWMAN

EXPLANATION OF PLATE 2 All figures are unretouched photographs of coated specimens F~gures1,2.-Pobpathurgranuloru~ Branson and Mehl F~tchvllleFormat~on, North Stansbur~(F- Base) Oral and aboral views, hypotype, BYU-1926, X25 3,4.-Polygnathur rnornatus smru Branson and Mehl Joana Limestone, Needle Range (A-Base) Oral and aboral vlews, hypotype, BYU-1935, X35 1~6.-Polygnathur rmtcortatur Branson and Mehl F~tchvllleFormat~on, North Stansbuty (F-20) Oral and aboral v~ews. hypotype, BYU-1929, X40 7,8.-P0lygnathur znornatus Branson Lodgepole hmestone, Logan (L-30) Oral and aboral vlews, hypotype. BYU-1934, X25 9,lO.- Polygnathus longrportrcrrr Branson and Mehl Lodgepole hmestone, Logan (L30) Oral and aboral vlews, hypotype, BYU-1928, X25 11,ld-Po~gnath~~extralobitur Schafer 11, F~tchvilleFormat~on, Rock Canyon (N-20) Oral vlew, hypotype, BYU-1931, X67 18, Fitchv~lleFormat~on, Rattlesnake Spur (R-130), Oral vlew, hypotype, BYU-1930, X73 12,13,16,17.-Polygnathuscommunu rommunrs Branson and Mehl 12,13, Lodgepole L~mestone,Logan (L-30) Oral and aboral vlews, hypotype, BYU-1932, X35 16,17, Joana L~mestone,Confusion Range (C-280) Oral and aboral v~ews,hypotype, BYU-1933, X35 14,15.-Pobgnath~~i~n~rpo~t~cur Bianson and Mehl. Joana Limestone, Needle Range (A-Base) Oral and aboral vlews, hypotype, BYU-1927, X35 CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 119 G J NEWMAN

EXPLANATION OF PLATE 3 All figures are unretouched photographs of coated speclrnens. F~gures1,2,3,4.-Pseudopo~gnathusprtmu~ Branson and Mehl 1,2, Lodgepole Lrnestone. Logan (L- 610) Oral and aboral views, hypotype, BYU-1922, X25 3,4, Joana Lrnestone, Confus~onRange (C-280) Oral and aboral vlews, hypotype, BYU-1923, X30 J,6.- PreudopoLygnatbus cf P. multrsmatus Mehl and Thomas Joana Lrnestone. Confus~onRange (C-280) Oral and aboral views, hypotype, BYU-1921, X35 7,8,9,10.- PseudopoLygnathus margznatus (Branson and Mehl) Lodgepole Lrnestone, Logan (L-30) 7,8, oral and aboral vlews, hypotype. BYU-1920, X35 9,10, oral and aboral vlews, hypotype, BYU-1921, X2S 11,12.-Pseud~pol~gnafbustnangulus fnangulus Voges Lodgepole Limestone, Logan (L-30) Oral and aboral vlews, hypotype, BYU-1924, X35 13~4.-Gnathodusdeltcatus Branson and Mehl Joana Lrnestone, Eureka (T-380) Oral and aboral vlews, hypotype. BYU-1936, X30 15,16.- Icnodus cf I costatus (Thomas) F~tchv~lleFormat~on, Rattlesnake Spur (R-150) Oral and aboral vlews, hypotype, BYU-1919, X35 17 -Spafbopathodus crasstden- tatus (Branson and Mehl) Lodgepole Lmestone, Logan (L-30). Outer lateral vlew, hypotype, BYU-1918, X30 18 -Elzctognathus laceratus (Branson and Mehl) Lodgepole Lmestone, Logan (L-30) Outer lateral vlew, hypotype, BYU-1919. X25 19 -Spathoparhodus aculeatus (Branson and Mehl) F~tchv~lleForrnatlon, Rat- tlesnake Spur (R-90) Inner lateral vlew, hypotype, BYU-1916, X22 CONODONTS AND BIOSTRATIGRAPHY, LOWER MISSISSIPPIAN, UTAH-NEVADA 121