Pennsylvanian Carbonates, Paleoecology, and Rugose Colonial Corals, North Flank, Eastern Brooks Range, Arctic Alaska
GEOLOGICAL SURVEY PROFESSIONAL PAPER 747
PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE COLONIAL CORALS, EASTERN BROOKS RANGE, ARCTIC ALASKA Panoramic view of the western Sadlerochit Mountains viewed to the east from Lisburne Group. The angular unconformity between the Mississippian and the the traverse of section 69A-1. The crest of the Sadlerochit Mountains and lighter Devonian carbonates is readily apparent in the center of the photo upper slope is formed by the dark-colored Permian and Triassic Sadlerochit graph. The Shublik Mountain::; are in the background. Photograph taken on Formation which overlies the medium-gray Mississippian and Pennsylvanian .June 19, 1969. Pennsylvanian Carbonates, Paleoecology, and Rugose Colonial Corals, North Flank, Eastern Brooks Range, Arctic Alaska By AUGUSTUS K. ARMSTRONG
GEOLOGICAL SURVEY PROFESSIONAL PAPER 747
Carbonate and paleoecological studies, and description of two new species of colonial rugose corals from four described sections of the Wahoo Limestone, Lisburne Group, Arctic Alaska
UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1972 UNITED STATES DEPARTMENT OF THE INTERIOR
ROGERS C. B. MORTON, Secretary
GEOLOGICAL SURVEY
V. E. McKelvey, Director
Librar;r of Congress catalog-card No. 72-600261
For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1.00 (paper cover) Stock Number 2401-2150 CONTENTS
Page page Abstract ______1 Systematic paleontology-Continued Introduction ______1 Family Aulophyllidae Dybowski, 1873-Con. Previous work and acknowledgments ______3 Corweniajagoensis n. sp ______10 Biostratigraphy______3 Family Lonsdaleiidae Chapman, 1893 ______14 Carbonate stratigraphy ______3 Genus Lithostrotionella Yabe and Hayasaka, Environments of deposition ______6 1915 ______14 Wahoo Limestone coral paleoecology ______9 Lithostrotionella wahooensis n. sp ______14 Systematic paleontology ______10 Graphic registry of stratigraphic sections and fossil Family Aulophyllidae Dybowski, 1873 ______10 localities ______16 Genus Corwenia Smith and Ryder, 1926, emend_ 10 Selected references ______18 Index ______21
ILLUSTRATIONS
[Plates follow index]
FRONTISPIECE. Panoramic view of the Lisburne Group outcrop, western Sadlerochit Mountains.
PLATES 1-4. Corwenia jagoensis n. sp. 5. Lithostrotionella wahooensis n. sp. and Corwenia jagoensis n. sp. 6. L1'thostrotionella wahooensis n. sp. 7. Lz:thostrotionella wahooensis n. sp. and photomicrographs of carbonate rock types in sections 69A-1, 68A-4A-4B. 8. Photomicrographs of carbonate rock types in sections 68A-5, 68A-1.
FIGURE 1. Index maps and biostratigraphic sections of the Wahoo Limestone______2 2-5. Photograph of- 2. West Sadlerochit l\Iountains section 69A-L______4 3. Lisburne Group outcrop to the east of East Sadlerochit ::vlountains sections 68A-4A-4B ______5 4. Egaksrak River section 68A-5 ______5 5. The unconformity between the Wahoo Limestone and Sadlerochit Formation______6 6. Composite and idealized section of the Lisburne Group, Sadlerochit Mountains, showing carbonate depositional cycles______7 7. Block diagram showing Pennsylvanian environments of deposition of the Wahoo Limestone______9 8. Graph showing corallite diameter and nmnber of major septa in Corwenia jagoensis n. sp ______11 9. Photograph of large corallum of Corwenia jagoensis n. sp. in outcrop, showing shape of colony and corallite growth______12 10. Graph showing corallite diameter and number of major septa in Lithostrotionella wahooensis n. sp______15 11-16. Location maps: 11. Ikiakpuk River section 68A-L ______17 12. West Sadlerochit Mountains section 69A-L______17 13. East Sadlerochit Mountains sections 68A-4A-4B______17 14. Egaksrak River section 68A-5 ______17 15. Central Sadlerochit Mountains section 68A-3______18 16. West Shublik Mountains section 69A-2______18
v
PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE COLONIAL CORALS, NORTH FLANK, EASTERN BROOKS RANGE, ARCTIC ALASKA
By AucusTus K. ARM•STRONG
ABSTRACT Also, a few other localities at certain stratigraphic levels The Pennsylvanian carbonates of four measured sections of the contain large numbers of colonial corals. The location Late :\Iississippian and Pennsylyanian \Vahoo Limestone consist of the study area is shown in figure 1. of 310-1,250 feet of deposits of the Lislmrne Group. Shallow The four stratigraphic sections discussed in this re water open-marine carbonates of }lorrow age overlie, without port were 1neasured with a Jacob's sta.ff and tape. hiatus, restricted marine to intertidal dolomitic carbonates of the Lithologic and fora1niriiferal samples were collected Alapah Limestone of latest }Iississippian age. The Morrow-age carbonates are predominately echinoderm-bryozoan wackestones every 5-10 feet. ~Iost of the corals were collected from and packstont>s, with minor amounts of ooid grainstones and within measured sections. Thin sections, cut from lith lime mudstones. 1.'he Atoka age carbonates are in part cross ologic samples, were petrographically described ~and bedded bryozoan-echinoderm and oolitic grainstones, 'vith asso studied for microfossiles. ciated minor amounts of thin-bedded dolomites. Outcrops of the Calcite and dolomite were identified in thin sections Wahoo Limestone in the Sadlerochit }Iountains indicate that Pennsylyanian sedimentation from }forrow to Atoka time gener by the Alizarin-red staining techniques of Friedman ally vrogressed from shallow-water 011en-marine sedimentation ( 1959). The carbonate classification is that of Dunham to higher-energy shoaling water oolitic sedimentation. ( 1962). 'J'he Atoka age rugose colonial corals, OorweniCl jagoensis The sedimentary features and structures used in this n. sp. and Lithostrotionella wahooensis n. sp., are described. study to delineate enviromnents of deposition and Paleoecological and biostratigraphic analysis of the carbonate beds associated with the colonial corals indicates that they lived paleoecology are described in detail by Logan, Rezak, in clear agitated water between oolitic tidal bars. and Ginsburg (196±), Shinn, Ginsburg, and Lloyd (1965), Roehl (1967), '¥"ilson (1967a, b, 1969), Shinn INTRODUCTION (1968a, b), Ball, Shinn, and Stock1nan (1967), Ball (1967) ~ and ~Iurray and Lucia (1967). The concepts Pennsyh·anian carbonates are well exposed in north for cyclic carbonate deposition cyclic which are used in eastern Brooks Range (see frontispiece) of eastern this report are those developed by Fischer (1964), Wil Arctic Alaska. The outcrops are suitable for detailed son (1967a, b), Coogan (1969), Armstrong (1967), and stratigraphic, facies, and paleoenvironmental studies. Armstrong, Macl{evett, and Silberling ( 1969).
1 2 PE1NNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA
"'"' " " ..."' 2l>~ ~ ~~ E~ ~~ ~~ "'"'~-~ c ~"S ~-g ~ 1 0 ~" - ~" n 1 u n u l~ ~00 c t500 ~_j c ~_j c '3 gJ~ "> ~ ea ~a:i ~~ ~~ ~a:i ~~ z m'7 uQ)";; !rl.O ;.~ 0 s·E ~0 ~u ~~l~*T,~~i .------~-1+0~~~--~------+-+ II ~~~~~--+------+-4~~~~~~--~------~~-~~~~"~~ :: i ...-:-r,;.,an•• 2 gnst 21 ~ pkst 21 .J"" ~ pkst ~" ,= I 1 >-- ~..,._ 1- Corwema Jagoensts • ~2 f--- __ I- Lithostrotionella ih"""~ mdst el"* • .ij "' ';;;;wkst ~ n. sp. 2 0 * , wahooensis n. sp. --m.~ "r 1--- "0 "0 z~l-- " ::!: ;; ,. ~ ::;: ,. ~~ ···-.:_::::_""',,, ,. =·~::;, ,. ~i;·~ z ~ <( E > "' :J Corwenia jagoensis ~ ~ f:1.:;;; ~ ~ :.·'oW ;·-~W ~ ;-· "" n. sp. ~ 0 "' ~ gnst '*',. +* pkst \\., D- G gnst corwenia ja.goensis 'T''f' * * ~ ~ ~ ~ mpkst ~ wk 300 'T' - 'T' i';;;'T' '', ' o X -20 mdst * j c. o;to<:f> z e pkst eo;t . --.------. +--'----'---'--.l..---1 FIGURE 1.-Inclex map of ..Arctic AlaHka and a generalized location map of the measured sections of the Wahoo Limestone in north eastern Alaska, with a graphic exr1lanation of the lithologic and fossil symbols used in this report. The stratigraphic position of the cornls described in this study is also shown. Detailed location maps of the stratigravhic sections are given in figures 11-16. CARBONATE STRATIGRAPHY 3 PREVIOUS WORK AND ACKNOWLEDGMENTS graphic zones within the Lisburne Group of Arctic Alaska; these biostratigraphic zones are based on the In 1962, Brosge, Dutro, Mangus, and Reiser extended microfossil zones developed by B. L. Mamet. the name Lisbume Group to car·bonatc rocks at \Vahoo \Vithin the area of this study, the Lisburne Group Lake and inclllCh~d in it the Em·ly Mississippian \Vach consists of the Alapah Limestone and ·wahoo Lime smuth Limesto11P, the Late Mississippian Alapah Lime stone. The basal Alapah Limestone at the Ikiakpuk sec stone, and the newly named Pennsylvania( and Per n tion (68A-1) in the Fourth Hange is of Mer~mec (Late mian \Vahoo Limestone. The \V•ahoo Limestone, as Mississippian) age (zone 13); to the north. m the Sa~ mapped in the a rPa of this rt>p01·t, contains some beds ~f lerochit Mountains at the \iV est Sadlerochit Mountam very latest Chester (latest Mississippian) ag~ but pri section ( 69A-1) , the base is lower Chesteran ~zone 1~i). marily contains beds of MorTo\\· (Early Pennsyl ,·anian) The microfossils indicate that carbonate sedunentatwn and Atoka (Middle Pennsy l n1nian) age and does not continued without a significant or recognizable hiatus contain strata of Permian agP. Armstrong, Mamet, and into Pennsylvanian time. In the Mamet zonal scheme, Dutro ( 1070), using microfossil zones, divided the the base of the Pennsylvanian system is at the base of Lisburne Group of central and eastem Brooks Hange zone 20 and is defined on the first occurrence of the Mor into a series of biostratigraphic units and defined the row fossils, Endothyra of the group E. nwsquensis Re~t base of the Pennsylvanian System in the Brooks Hange. linger·, Lipinella, sp., JJfillerella sp., and Neoarchaedis Detailed accounts of the history of the study of the Car cus gnmdis ( Reitlinger). Atokan age (zone 21) carbon boniferous rocks of the Lisburne Group can be found ates contain the microfossils Olimacam1nina cf. 0. moel in Bowsher aml Dutro (HJi>7) and Armstrong, Mamet, leTi Reitlinger, Eoschubertella sp., Pseudostaff'ella sp., and Dutro (1970). Reiser, Dutro, I3rosge, Armstrong, and Globi1.,•alvulina sensu stricto. The absence of Fusu and Detterman (1970) haYc made geologic maps 1: 63, Zinella spp. and Profusulinella spp. is a serious detri :160 scalP) of the Sadlemchit Mountains that delineate ment to exact correlation with other established Penn the outcrops of the L isbume Group, including the sylvanian sections. The presence of these genera would \Yahoo Limestone. substantiate the conclusion that the uppermost beds are I wish to express my appreciation to In,in Taillenr, not Des Moines in age. party chief during the summer of 1968, and Hillard N. Hugose corals are known only from beds of Atoka Heiser, party chief during the summers of 196!) and age of the \Vahoo Limestone; as yet none has been 1070, for their generosity in supporting my coral collect found in beds of Morrow age. The corals are repre ino· and stratigraphic studic·s. I \Yish to thank the N·aval sented by two new species, Oorwenia jagoensis n. sp. Hesea rch La bora tory ( Ba ITO\V), office of val ;\..~ctic. ~a and Lithosh'otionella walwoensis n. sp. The most closely Hesearch, for their logistical support of my fieldwork related corals are Dithost?'otionella orboensis Groot durino· the summers of 1968-70. Two specimens of (1963) from the upper Moscovian of Spain and Peta corals used in this study, collected by Shell Oil coloni~l lamis mohikana Fomichev (1953) from the upper .Mos Co. geologists in 1960 and 1963, \Yerc given to the U.S. covian of the Donetz Basin, U.S.S.R Oorwenia jagoen Geological Suncy, and 'appreciation is expressed toR. sis n. sp. shows close similarity to the upper .Moscovian E. McAdams and G. E. Bmton, .-ice-presidents of Shell corals Oonoenia symmetrica (Dobroljubova) from Oil Co. The photographs and thin sections were made Spain and Moscow and Donetz Basins of U.S.~.R Taxa by Kenj i Sakarnoto and Robert ShPly, respecti ,·ely, both similar to L. 1oahooensis have not been descnbed from of the V.S. Geological Suney. Pennsylvanian age sediments of the I am grateful to my colleagues, J. Thomas Dutro, ,Jr., Cordille~an r~gion. of North America. The apparent closer relatwnslup of \Villiam J. Sando. and \Villiam A. Oliver, Jr., who the two Atokan-\Vahoo corals to forms described from helped in preparation of the manuscript and provided Eurasia is probably due to the lack of detailed system critical review. James Lee \Vilson helped in the devel atic studies on Pennsylvanian colonial corals from the opment of concepts relating to the environments of dep Cordilleran of North America. osition and paleoecology and also reviewed the strati oTaphic parts of the manuscript. I wish to thank Mah CARBONATE STRATIGRAPHY lon .M. Ball and Robert Ginsberg for their review of the manuscript. Brosge, Dutro, Mangus, and Heiser (1.962, p. 2191) described the type section of the vVahoo Limestone near BIOSTRATIGRAPHY \Vahoo Lake as containing carbonates of Pennsylvan Armstrong, Mamet, and Dutro ( 1970, 1971) and ian (?) and Permian age. In the are~ of this report, tl~e Armstrono· and Mamet (1970) have described the se \Vahoo Limestone as mapped by Heiser, Dutro, Brosge, quences of Mississippian and Pennsylvanian biostrati- Armstrong, and Detterman (1970) c.ontains carbonates 4 PB.:- FIGL"RE 2.- West Sadlerochit :\fonntltins section (69.-\-1) sho\Y· of the Permian and Triassic Sadlerochit Formation is sho~n1 in~ line of tnlH'l'Se and stratigraphic footage marks. 'l'he eon ill the right center of the photogravh. 'l"he df'w is to the south ; tact lJeh,·een the thin-lleudecl dolomitic ear bonn tes of the Ala ill the lm ckgrounrl nrP the Shublik ::\[ountnins. The \Y ell pah Limestone anrl the massiYe limestone of the "'ahoo Lime exposPrl l'Pnnsyl\'anian-l'el·mian unconformity shown in fig stone is sho\Yn at 310 feet. Locality of 'the type specimf'n of ure i:i is located a few hundred yards to the right of the con LithostroUonella wahooens-is n. sp. is indicated. The contact tact shown in this photograph. CARBONATE STRATIGRAPHY 5 "" I Base of continuous section f FIGURE 3.-The Lisburne Group outcrop on the hillside to t he FIGURE 4.-The Egaksrak River section (68A- 5), showing the eas't and opposite the line of traverse of East Sadlerochit contact of the Sadlerochit Formation with the underlying :\fountains section ( 68A-4A-4B) . Thin-bedded dolomites near Wahoo Limestone and the rubble-covered slope at the base of the 'top of the Alapah Limestone form the rublJle-covered slope 'the section. The sec'tion was measured over the crest of the lJeneath the massiYe cliffs of the Wahoo Limestone which ridge. The Gorwenia jagoen8i8 n. sp. zone, named for the pro begins at the 860-foot mark. The basal lJeds of the Wahoo lific species, occurs on 'the apex of the hill. View is to the Limestone are of late Chester age. The varied topographic ex east. pression of the Li~-'l.Jurne Group clearly reflects the several carlJonate rock types formed in differing ancient depositional em·i ronmen ts. (See fig. 6.) ates which form these "marker" beds show their com position to be 50-70 percent dolomite rhombs ranging grainstones, and pelletoidal-bioclastic packstones and from 25 to 50 microns and the remainder fragmental grainstones (pl. 7, figs. 6, 7). The Morrow age carbon subangular grains of detrital quartz ranging from 50 to ates to the east in the Egaksrak River section 68A-5 100 microns. Limonite and hematite fill the interstices (fig. 4), are again low-energy bryozoan-crinoid' wacke between many of the dolomite rhombs. The iron oxides stones and packstones (pl. 8, figs. 4-6) with only minor probably are the weathering products of pyrite. Asso amounts of superficial ooids and oolitic grainstones. ciated with the grainstones are thicker nonlimonitic lime The Atoka age cat'bonates are predominantly grain mudstones and wackestones which contain 5-30 percent supported packstones and grainstones with minor detrital quartz whose grains range from 50- to 100- amounts of wackestone and lime mudstones. Character microns. Glauconitic shale pmtings, 1- 4 inches thick, are istically these beds are 5- to 15-foot thick, weakly cross not uncommon between the massive carbonates. bedded, well-stratified oolitic grainstone which contains Atoka age carbonates are a!bout 700 feet thick at the well-developed ooid grains (pl. 8, figs. 2, 7) that are Egaksrak River section. Bryozoan-echinoderm wacke from 0.5 to 1.0 mm in diameter. Some of the ooids have stones and packstones are the dominant rock types from numerous layers and many show much evidence of alo-al 0 to 400 feet below the top of the section. Within this boring. The nuclei of many of the ooids are rounded f~s interval true oolites are rare, but oolites are sporadically sil fragments. Associated with the ooids are superficial present from 410-570 feet below the top. Oolitic grain ooids and rounded and coated lithoclasts from 1 to 4 mm stones are well developed from 590 to 600 feet below the in length. Commonly occurring with these grainstones top of the section (pl. 8, fig. 2). Within the Egaksrak are abundant Foraminifera and calcareous algae. The section the spherical algal-foraminiferal colonies of bryozoan-crinoid grainstones and packstones are formed Osagia sp. are locally common at 160, 560, and 615 feet by Formaminifera and broken 'bryozoan fragments below the top of tl1e section. Osagia sp. has also been whose interiors are generally filled with micrite (pl. 8, found in the East Sadlerochit Mountain section 68A- figs. 3, 4). A small percentage ( 1-2 percent) of these 4.-\.-4B at 40-50 and 120-130 feet below the top. fossils have glauconite filling t he internal spaces. The Tlte Ikiakpuk section, 68A- 1, in the Third Range, is carbonates bebYeen some of the oolite beds are 6-ine'h to so nth of the above sections (fig. 1). The section was 4-foot thick, argillaceous, arenaceous, dolomitic, and measured on a series of exposures in stream-cut banks. hematitic. These "marker~' beds persist oYer long dis Here the Pennsylvanian '\Yahoo Limestone is some 375 tances in the Sadlerochit and Shublik Mountains and feet thick. The Atoka beds are about 135 feet thick and gi\·e the '\Yahoo Limestone its characteristic yellowish are formed 'by tectonically stressed ooid foraminiferal orange weathering color. Thin sections of the carbon- grainstones (pl. 8, figs. 7, 8). The underlying Morrow 6 PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA beds also show grain growth due to tectonic stress and Echooka Member are conglomerates or conglomeratic are bryozoan-echinoderm packstones and grainstones. sandstone formed in part of rounded chert and lime In the area of this study, the P ermian and Triassic stone pebbles and cobbles derived from the underlying Sadlerochit Formation conformably overlies limestones \Yahoo Limestone. of Atoka age. Detterman ( 1970) reports that the basal Echooka Member of the Sadlerochit Formation con ENVIRONMENTS OF DEPOSITION tains a brachiopod fauna of early Kazanian (earliest \Vithin the area of this study, the vVahoo Limestone Late P ermian) age. The unconformity (fig. 5) repre is part of a two-phase carbonate depositional megacycle sents a hiatus of Des Moines through Leonard, and pos which began in Late Mississippian time and continued sibly early Guadalupe, time. The westward thinning of into Pennsy: van ian time (fig. 6). This carbonate sedi the Atoka age carbonates in the Sadlerochit Mountains mentation is part of a regionally transgressive Lisburne (fig. 1) suggests uneven erosion, probably caused by Group sequence that began at the Ikiakpuk section differential uplift previous to sedimentation of the Sad ( 68A- 1), Third Range, in Meramecian time (zone 13) lerochit Formation. At many localities the highest few and at the \Vest Sadlerochit Mountain section (69A- 1) feet of Atoka age carbonates beneath the Sadlerochit in Chesteran (zone 16i) time (Armstrong and others, Formation show evidence of vadose weathering in the 1970). Above the Kayak ( ?) Shale the basal Late Mis form of enlarged vertical joints and vugs filled with a sissippian Alapah limestones are typically well-sorted terra rossa-like clay (fig. 5). The basal beds of the pelletoidal-bioclastic-grainstones and packstones and lesser amounts of ooid grainstones. Overlying these are beds of poorly sorted noncurrent-deposited bryozoan echinoderm packstones and \Yackestones. The environ ment of deposition for these carbonates is interpreted as open platform, normal marine (figs. 6, 7). The lithology and sedimentary structures of the higher beds of the Alapah Limestone clearly indicate a progressively more restricted marine environment of deposition and the de velopment of a regressive sequence of carbonates. These younger beds show a progressive decrease in biotic di ,.e,·sity, an increase in the amounts of pelletoida.l packstones and lime mudstones, and an increase in the percentage of dolomite. This regressi\·e sequence is ,·ery well developed in the East Sadlerochit :Mountain sec tion, 68A-4A.-4B, (fig.l). At a level950 feet below the top of the section, the Alapah Limestone is a fine grained light-brown-gray cherty dolomite with well de\·eloped algal mat and birdseye structure; these features indicate deposition in very shallow marine to intertidal e1wironments. A similar sequence of rock types can be seen in the Alapah Limestone at Ikiakpuk Creek and in the \Vest Sadlerochit Mountains sections. The latter exposure has, at the same general strati graphic level, restricted marine sediments of somewhat dolomitized thin-bedded pelletoidal packstones but is de,·oid of algal mats. The restricted marine shallow FIGURE 5.-Contact between Atoka carbonates of the 'Vahoo \Yater to intertidal carbonates in the upper beds of the Limestone and Permian sandstones of the Sadlerochit Forma Alapah Limestone are generally thin bedded and platy, tion (upper arrow). Large eobbles and smaller pebbles of 'Vahoo Limestone are present at the base of the Sadlerochit and they form talus slopes beneath the massiye lime Formation. Cracks and solution joints (lower arrow) in the stones of the \Yahoo Limestones (figs. 2, 3). upper part of the 'Vahoo Limestone are tilled b:r a terra rossa This regressiye suite of carbonates (fig. 6) which like day. The hiatu~ bet\\"een the 'Vahoo Limestone and Sad lero('hit Formation rf'presents a ll of Des :\Ioines, l\Iissouri, culminates in an intertidal-restricted marine facies is Virgil, and Early Permian time. The ruler is 6 inches long. overlain, as indicated by microfossil assemblages (Arm- ENVIRONMENTS OF DEPOS1ITION 7 strong and others, 1970), by a marine transgressive car Environments of deposition bonate facies of bryozoan-eehinoderm wackestones and (J) packstones eontaining mierofossils of latest Chester age UJ (/) a: (/) Q) (zone 19). In the area of this report, this second earbon UJ Q) -~ (J) c 2 0 0 c 0 ate transgressive cyele of the Lisburne Group began in _J N z 1:J Q) ~ - .!!2 c c. latest Chester time and eontinued aeross the Mississip Q (/) eli ctl ctl 0 () (/) E 1- (/) 0 (/) (fi Q) 1:J ::e (J) z Cl. 0 u pian-Pennsylvanian boundary without a hiatus (fig. 6). UJ u 0 (/) (J) 0 0 a: c. The earliest ~forrow age carbonates are lithologica.lly a: a: u Q) Q) > UJ a: 0 .c. u 1:J ~ ~ (J) (J) Cl. (.9 LL ~ 1- c ctl E ro similar to those of very latest Chester age and are bryo co B 0. ~ ~ .Eu 0. .... E ;;,::.'...... :: .. ·:··: :::J c -co c zoan-echinoderm wackestones and paekstones that were z au.. u (/) Q) 0 Q) .:¥ ~ b vanian to the unconformity at the base of the Permim1, \J- 0 1 * - ·-::2(/)> OT o lo c 4:: oo the general trend in sedi1nentation is towards higher c lo Q) 200 olo 1-o energy water, that is a shoaling water oolitic. environ a.. Q ~ I 0 -t<· v Inent of deposition. This is inferred from the strati z 20 -o _J ctl c > ..2: B 400 1 -o lr and many beds with well-developed ooids. For the (J) > (/) z (/) ~ Q) I * I * ( c E Sadlerochit Mountains, the interpretation of this shift z c e rl * lr UJ Q) 0 :::i 1-o I* in environments of deposition from the early Chester to Cl. a.. ::2 01 0 10 ) ToT-o Atoka time is graphically illustrated in figure 6. .... 0 Q) 0 I r 1o s: ..r::. T The Wahoo Li1nestone echinoderm-bryozoan pack 0 c. ctl 600 T * _J :::l 0 3: I * IT stones and grainstones have 0.5-2 pereent bright green 0 I* 1' 20 glauconite grains, most of it oeeurring as internal 1--- II *I ------19 1 * r fillings in Foraminifera and bryozoan fragments and *1 * 11' i Q) c I 'T I occasionally as free grains. Cloud (1955) and Loehman :; 800 'T'I * .l:l Balk (1957) give detailed aeeounts on the environ (/) l'J: 1' T '* Q :::i I k I* 18 ~I) ments of deposition and physical limits of gl~auconite I * I 'T i,-- 18 -/:7,: formation. In general these are : normal salinity, slight 1-Y~- 1""""'~7- ly redueing eonditions at sites of origin~ bottom sedi c 1000 -/""""/ ments rich in organic material, a water depth greater ctl - V- I, 1\ ·a. 17 - i/- c. v ,/ than 25 feet~ and low terrigenous sediment influx. The z (/) 1/ (/) ~ Q) I presence of glaueonite in the bryozoan-eehinoderm Cl. (/) c "' let> Cl. (/) 1<1> I 1' 2(/) B grain-supported carbonates suggests that the glaueonite (/) ~ Q) (/) '*' T 'T T* (J) .c. Q) 1200 I 4> (/) E formed in a redueing environment in elose juxtaposition u ;~.c I 0 (J) :::i I ~ - to oxygenated '\Vaters in whieh bryozoans and erinoids 2 ~ I I ffi T T *T c. .c. 16 i thrived. The materials from these two environments c. ctl let> ::J c. ctl I *I were brought together by the activities of ehurning and ~ I k I q, 1400 _, burrowing organisms and by the ehanneling, rework j.*~'T' \ ing, and sorting activities of tidal ehannels (diagram -1 o"''* IT 1 r l--o matieally shown in fig. 7). -1 -o T .<:: liZ\ ...J~ ~U) -- <( -- the Sadlerochit Mountains showing the interpreted shifts of z f:7 Solitary coral carbonate environments of deposition at various strati 0 ~ graphic levels. Explanation of symbols for fossil particles UJ> Q Colonial coral 0 given in figure 1. 8 PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA ._,.-----Salinity increases----- Intertidal-supratidal; Restricted platform; bioclastic I Open ~latform; normal marine, I imited fa~na, bi?- lime. mudstones-do-~ wackestones i.n lagoon~ and clast1c. w~ckestones and packstones; b1oclast1c lom1tes-algal mats bays; bioclastic sands 1n t1d- sands 1n t1dal channels al channels Mean sea level J atnes Lee Wilson (written commun., March, 1971) ish orange-weathering arenaceous dolomites and the states thick-bedded oolitic grainstones are interpreted as repre The presence of glauconite in grainstones is common in car senting the interstratified record of very shallow lime bonate rocks all over the world despite the fact that i't is a mud tidal flats developed directly over oolitic tidal bars. mineral of reducing environment. Stratigraphic observation and This close physical relationship of oolitic grainstones studies indicate that glauconites are associated with zones of and thin -1bedded lime mudstones and dolomites is not slow deposition, often forming in strata which are overlain later by an unconformity. It seems reasonable that under a situation of unique to the Wahoo Limestone. Wilson, Madrid-Solis, Yery slow deposi'tion, conditions exist for the organic rework and Malpica-Cruz (1967, p. 81) report a simila.r se ing of sediment as well as mechanical reworking. Grains are car quence of oolitic grainstone and unfossiliferous mud ried down into the substrate in a reducing environment in which stones from Pennsylvanian carbonates of southwestern iron is concentrated (probably also by slow intermi'ttent deposi New Mexico. J. L. Wilson (written commun., 1971) tion during 'vhich time no clastic material is introduced 'to mask it). Later such grains are brought up and exposed to current states that similar and wave action by marine channeling an'd further burrowing; dolomitic marker beds are also common in Devonian and Mis during the in'terim of burial glauconite has formed from the mud sissippian sections of Montana where they are almost certainly and organic slime caught wi'thin the grains while they have re tidal flat and sebkha deposits 'vi'th the former sulfate minerals mained buried. The 'Vahoo Limestone glauconitic grainstones leached out. In places such beds are de-dolomitized. In Mon tell us that not only slow deposi'tion prevailed but that sufficient tana in the Mission Canyon Limestone such beds are a:lso asso mud occurred in between oolite bars to create impermeability ciated with oolitic grainstones but are commonly separated fron1 and a reducing iron-rich environment. Most pore-filling glau these by a transitional zone of birdseye pelletoidal mudstone and conite is basically a product of organic feces in the mud. These grainstone. ideas derive in part from discussions with H. B. Stenzel. The EO'aksrakb River section has 400 feet of ooid The oolitic grainstones which are found in associa to echinoderm-bryozoan paekstones-wackestones and tion with the glauconitic grainstones are well-stratified, grainstones above the highest well-developed oolite generally 5-10 feet thick, and poorly crossbedded. In grainstones (fig. 1). These carbonate beds are believed many places, the beds are capped by dolomites whieh are to be a younger Atoka age than those carbonates pre frmn 6 inches to 2 feet thick, argillaceous, arenaceous, served beneath the Permian unconformity in the Sad and limonitic.; the dolon1ites weather to pale yellowish lerochit Mountains. orange. This roek is eomposecl of dolomite rhmnbs some Osagia sp. eolonies occur at 160, 560, and 600 feet 30 microns in size and with more than 30 percent silt below the top of the Egaksrak River seetion and possi size detrital quartz. BalFs (1967) description of modern bly indicate a very shallow water environ1nent of depo earbonate. sand bodies indieat~. that the Wahoo oolite sition. These beds also eontain increasing amounts of grainstones were probably formed in a tidal bar belt en micrite and significant amounts ( 5-20 percent) of silt vironment transgressive over the underlying sediments to fine-sand-size detrital quartz. These factors possibly that are eharaeteristic of an open platform normal ma indicate that the beds above the last oolitic grainstone rine environment "\vhich is probably slightly reducing represent the development of a slowly regressive car and glauconite-forming. The thin-bedded pale yellow- bonate depositional phase. WAHOO LIMESTONE COR,AL PALEOECOLOGY 9 Shoal; lime sands and oolites bryozoan-echinoderm wackestones-~ Open platform; normal marine, fauna of brachiopods, packstones and crossbedded grainstones; superficial ooid and bryozoans, crinoids; bryozoan-echinoderm wacke I ooid packstones-grainstones; Osagia grainstones stones and packstones EXPLANATION Current deposited Noncurrent deposited ~l ~ EZ3 ~ Environments of abundant Oo I i tic-superficial Bryozoan-crinoid pack rugose corals ooid grainstones stones-wackestones ~ Algal mats ~ ~ ~ Bryozoan-crinoid Lime mudstone and pel grainstones letoid packstones Dolomitic I ime mudstones and dolomites FIGURE 7.-The Pennsylvanian environments of carbonate deposition of the W11hoo Limestone on the north flank, eastern Brooks Range. Yertical distance is less than 100 feet. horizontal distance 50-100 miles. lime mud indicate a somewhat lower energy environ WAHOO LIMESTONE CORAL PALEOECOLOGY Inent than simple ooicl tidal banks. In the Bahamas The colonial corals, Corwenia )agocn8i8 n. sp., and 1ithoelasts are n1ost common in the, tidal channels and Litlw8trotionel7a wahooewsi8 n. sp., occur in large nmn interbar S\Yales. The environments of coral growth are bers in certain horizons of the "'Vahoo Limestone. Their probably below and to the side or between the oolite growth habit and spatial relationship within these beds banks but above the reducing environments in which indicates that individual colonies lived separated from the glauconite was fm'lned. :Many of the cor·alla appear each other and did not forn1 biostromal or biohermal to have been buried in a growth position, but others ap masses. pear to have been turned over and broken before burial. The colonial corals in the Wahoo Limestone are These latter factors plus the lithoclasts found associated found in close association with oolitic grainstones and with .the eorals suggest periodic high-energy \Vave mo packstones. The specimens are not found generally in tion, whieh was probably associated with storn1 activity carbonates n1ade entirely of ooids but in ooid admix (Ball and others, 1967). The origins of these micritic tures that have varying amounts of micrite, pellets, pelletoidal bioelastic-oolitic packstones are somewhat small lithoelasts, and abundant fragments of brachio pods, bryozoans, echinoderms, calcareous algae, fusuli analogous to similar calcareous sand bodies of the Ba nids, and smaller foraminifers. This rich and diverse hama Banks described by Ball (1967, fig. 9, particularly biota indicates a shallo,v-water environment. The abund fig. 19). A hypothetical reconstruction of the Wahoo ant fragments of calcareous algae and well-developed Limestone environments of deposition is shown in fig ooid grains, 0.4-0.8 mm in size, indicate deposition in ure 7, and the preferred environments for coral growth or adjacent to shoaling water. The presence of micritie are shown as between and below the ooid sand tidal lithoclasts, as n1uch as 4 mm in size, and pore filling by bank. 10 PENNSYLVANIAN CARBONATES, PALE·OECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA The association of colonial rugose corals with grain Stratigraphic section USNM catalog No. Corallum fragment stones having oolites indicates that they needed a rela. (em) tively high-energy clear shoaling-water environment. 68A-4A ______161034 Holotype ____ _ 8X lOX 10 The general absence of corals from the packstones and 68A-5 ______160533 Paratype ____ _ 12X 15X20 grainstones which are interstratified with the ooid-bear 68A-5 ______160534 _____ do ______8X lOX 11 68A-5 ______160535 _____ do ______15X24X26 ing beds but which lack oolites provides evidence that 68A-5 ______160536 _____ do ______lOX 12X20 these corals tolerated a narrow range of environments. 63B-808 ______160537 _____ do ______5X 6X 9 68A-L ______160538 _____ do ______6X 12X 13 The Pennsylvanian rugose colonial corals of the Lis 68A-4A ______161035 _____ do ______5X 9X 14 burne Group appear to be ·more environmentally sensi 68A-4A ______161036 _____ do ______6X 7X 15 68A-5 ______161037 _____ do ______15X 19X20 tive than the ~fississippian (Meramec) lithostrotionoid 68A-5 ______161038 _____ do ______6X 7X 12 corals of the older parts of the Alapah Limestone of 68A-5 ______161039 _____ do ______lOX 14X 14 600-201 ______161040 _____ do ______9X 12X 15 the Brooks Range. These older rugose corals, as indi cated by the rock record, could tolerate slower 1noving water with apparently higher amounts of suspended Transverse thin Longitudinal thin sections (2"X3") sections (2"X3") lime mud particles. Annstrong (1970) reported that in Stratigraphic section Number of Number of Number of Number of the Kogruk Formation, DeLong ~fountains, the litho thin sections corallites thin sections corallites strotionoid corals are abundant in ooid grainstone and are common in bryozoan-crinoid packstones and 68A-4A ______2 20 3 5 68A-5 ______1 4 2 6 wackestones. 68A-5 ______1 23 2 8 68A-5 ______2 4 1 2 68A-5 ______1 4 1 1 SYSTEMATIC PALEONTOLOGY 63B-808 ______1 3 2 4 68A-L ______2 5 1 3 Family Aulophyllidae Dybowski, 1873 68A-4A ______1 1 1 1 68A-4a ______1 11 1 4 Genus CORWENIA Smith and Ryder, 1926 emend. 68A-5 ______3 23 1 2 68A-5 ______2 21 2 5 Oorwenia Smith and Ryder. 1926, Ann. Mag. Nat. History, v. 17, 68A-5 ______2 34 ] 2 p. 149. 600-201 ______3 16 1 4 Oorwenia Smith and Ryder. Hill, 1940, Paleontographical Soc. Mon., p. 100--101. Oorwenia Smith and Ryder. Hill, 1956, in Moore, R. C., ed., Description.--The holotype, USNM 161034, is a fas Treatise on invertebrate paleontology, Part F, Geol. Soc. ciculate corallum (fig. 8). Corallites arise by offsets. A America, p. F288. corallum is approximately 40-45 em in dia1neter. In Oorwenia Smith and Ryder. Dobroljubova. 1958, Akad. Nauk. SSSR Paleont. Inst. Trudy, v. 70, p.ll4-117. transverse section eorallites range from 5 to 18 mm in Oorwenia Smith and Ryder. Groot, 1963, Leidse Geol. Meded., diameter, and long, slightly sinuous major septa range pt. 29, p. 66. from 20 to 32. The Inajor septa are continuous through the dissepimentarium and are 100-125 microns thick at Type species.-Lonsda.leia rugosa McCoy, 1849, their junction with the corallite wall. Within the tab Lower Carboniferous, upper Visean; Corwin, Wales. ulariunl the major septa a.re dilated and are 250-350 Dia.gnosis.-Phaceloid aulophylline corals with a microns thick at the tabularium wall, tapering grad radially or bilate~ally sym1netrical axial columella; ually to their distal ends. The axial side of the tahu septa thin or dilated in all quadrants; dissepitheca may larimn wall and the dissepiments are thickened by a be present; some forms have. lonsdaleoid dissepiments; 150- to 300-micron-thick stereozone (pl. 1, figs. 2, 4). In tabularium with periaxial ~and axial series of tabellae, transverse section the minor septa are short, penetr31te strongly arched distally and peripherally convex. only a short distance past the dissepimentarium into the (Modified in pa,rt from Groot, 1963, p. 66.) tabularium,.and are commonly discontinuous within the Corwenia jagoensis n. sp. dissepimentarium. The counter septa, and in some spec imens, the cardinal septa are continuous with the Plate 1, figs. 1-6; plate 2, figs. 1-5; plate 3, figs. 1-4; plate 4, figs. 1-4 ; pia te 5, figs. 2-4 columella; the other major septa are genera.Iy with drawn from the axial region. The ~olumeHa is cle~arly 11/ ate rial.-The Inaterial and specimens avaiJ,able for formed by the dilation of the axial end of the eounter study are shown in the following tabulation. septum and ranges from 1-4 mm long and 100-200 SYSTEMATIC PALEONTOLOGY 11 20 19 EXPLANATION Stratigraphic USNM 18 Symbol section Catalog No. Type 8 68A-4A 161034 Holotype 17 $ 68A-4A 161035 Paratype ii!J 60C-201 161040 Do. 16 68A-5 161039 Do. 15 14 13 12 11 10 9 0::"' .....UJ UJ ~ 8 ...J :::;;=' z 7 o::' UJ..... 6 UJ :::;; 14 EXPLANATION Stratigraphic USNM 13 Symbol section Catalog No. 0 68A-5 161039 12 + 68A-5 161038 11 68A-5 161037 * 68A-5 160533 10 X X 68A·4·A 161036 9 8 7 6 5 4 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 NUMBER OF MAJOR SEPTA FIGURE 8.-Corallite diameter and number of major septa in Corwenia jagoensis n. sp. 12 PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA microns thick. In transverse thin section the columella in size followed by deposition of interlocking rhombs is commonly surrounded by a spiderweb pattern that is 0.1- 3 mm in size. formed in the plane of the thin section which cuts the Specimens USNM 161035, 161037, 161040, 160535, and upturned axial surface of the tabulae and their septa.! 160536 typify the large corallites of this species and are ridges (pl. 1, fig. 3). very similar to the holotype in morphological details. \Vi thin coralla the smaller corallites (diameter 8.0 Specimens USNM 160533 and 160539 typify the mm or less, 21- 24 major septa) resemble the larger smaller corallites of the species with fewer major septa. corallites except for their narrower dissepimentarium Thin sections of USNM 160539 show tha;t the corallites that is composed of two rows of dissepiments and their range in diameter from slightly more than 4 mm to 10 minor septa that are discontinuous within the dissepi mm and have 19-23 major septa. Morphological features mentarium. in general are similar to those of the holotype and are A coralli{e 18 mm in diameter in transverse thin sec very similar to those of the smaller corallites in the tion (pl. 1, fig. 6) has a dissepimentarium 2.5- 3.5 mm corallum of the holotype, however, the major septa are wire formed by 4-6 rows of globose dissepiments. The slightly longer and the axial structures are better peripheral stereozone is present on the axial side of the developed than in the holotype. last ring of dissepiments facing the tabularium. The Occurrence.-The holotype, USNM 161034, and the tabulae, generally incomplete, show a tendency to de paratypes, USNM 161035 and 161036, were collected 250 velop an inner and outer series of tabulae (pl. 1, fig. 5). feet below the top of the East Sadlerochit Mountains The columella is persistent and slightly sinuous. The section, 68A-4A-4B. Paratype USNM 160537 was col tabulae near the dissepirnentarium slope up from the lected by Stanley F. Schindler, Shell Oil Co., in 1963, in horizontal 20°-30°, whereas those near the columella a measured section about 1.25 miles west of section 68A- may slope ;)0°- 60° from the horizontal. 4A-4B. at a stratigraphic level in the Wahoo Limestone The microstructure of the corallum is generally well 165 feet below the contact with the Sadlerochit For preser·ved (pl. 1, figs. 1-4). The corallite wall, 100- 125 mation. Other paratypes were collected at the follow microns thick, is formed by dense fibrous calcite with ing levels below the top of Egaksrak River section the fibers oriented normal to the exterior wall. The wall 68A-5 (fig. 9): USNM 161039 at 230 feet, USNM can be divided into two parts-an outer dark-gray band, 161037 and 161038 at 270 feet, USNM 160533 and 160534 30-40 microns thick, and an inner lighter colored band, at 285 feet, and USNM 160535 and 160536 at 450 feet. 70- 95 microns thick. The septa appear to be composed Paratype USNM 160538 was collected about 70 feet of a slightly different textural type of calcite. The junc below the top of the Ikiakpuk Creek section 68A- 1. tion of the septa and the corallite wall is distinctly Paratype USNM 161040 was collected by Stanley F. marked by an embayment of the septa into the corallite Schindler, Shell Oil Co., in 1960, in a measured section wall. The microstructure of the corallite wall and the near Salisbury Mountain, long 146°19' W., lat 69°14' N. septra is similar to and conforms to the type described The specimen was collected in the "T ahoo Limestone 5 by Kato ( 1963, fig. 17C) as lamellar. In transverse sec tion, the septa in the dissepimentarium have a dark cen tral band 10- 15 microns wide, and at either side fibrous calcite is at nearly right angles to the central band (pl. 1, fig. 1). The septal stereozone in the tabularium ap pears to be a simple thickening of the fibrous calcite forming the outer layer of the major septa. The stereo zone on the dissepiments is also fibrous calcite (Don pl. 1, fig. 4), but where it abuts against the septal stereozone, a sharp line of demarcation can be seen (pl. 1, figs. 1-2). Petrographic studies dearly show that the columella is an extension of the counter septum and that the tabulae are fused to it. In longitudinal thin sections, the dissepiments and tabulae are 20- 35 microns thick and are composed of dense calcite crystals which are fiber shaped to rhomb shaped and 4 microns in size or smaller FIGURE 9.-Large cora1lum of Convenia. jagoensis n. sp. showing shape of colony and corallite growth. Scale shown by pencil (pl. 1, fig. 4). The sequence of void filling within., the in lower right. Corallum occurs in a coral-rich bed of the corallum began with an ,initial deposition on all in Wahoo Limestone al.Jout 450 feet below the top of the Egaksrak ternal surfaces of rhombs of sparry calcite 10-15 microns River section 68A-5; see figure 1 for stratigraphic location. SYSTEMATIC PALE feet below the contact with the Sadlerochit Formation Speeimens of 0 orwenia jagoensis n. sp. from the in limestone beds which contain a microfossil fauna of Atolm age beds of the vV ahoo Limestone are believed to Atoka age. represent an unstable forn1 because they show consider C 01'Wenia jagoensis n. sp. is found within the Wahoo able structural variation in the eorallites of a corallnm Limestone in a biostratigraphie zone of Atoka age. Asso and of different coralla. One is strongly tempted to de eiated microfossils are Jlfillerel1a spp., Endothyra of the fine two species of Oorwenia. from the vVahoo Limestone group E. nwsquensis Reitlinger, Lipine77a sp., N eoarch material, based on eorallite size and nmnber of septa, aediscus grandis (Reitlinger), Climaca1nmina ef. C. clevelop1nent of the eolumellae, and length of 1najor moellel'i Reitlinger, D t'inella sp. 1 Eoschubel'fella sp., septa, but even within one colony wide gradations exist Globivalvu1ina sensu stricto, and Pseudostaffella sp. in corallite diameter, number of septa, and n1orphology. Remadcs.-The fasciculate rugose eorals of the The eontrast behveen corallum end members of the Wahoo Limestone present problems of classification at population is great, as can be seen by comparing speci both the. generic. and specific. leYels and appear to repre mens LTSN~f 160534 (pl. 3, fig. 1) and USNM 161040 sent a transitional fonn between the Mississippian (pl. 4, fig. 4 ; pl. 5, figs. 2---!). genus Corwenia Smith and Ryder and the Pennian Specimens USNl\I 160534 and 161039, with their genus H eritschioides Yabe. smaller corallite diameters, longer major septa, and less A conservative concept is used in this study to define steeply inclined inner tabellae, resemble more closely the genus Corwenia. Groot's (1963, p. 66) observations the generic. characteristics of 0 orwenia. on the type speeies of Oorwenia rugosa (MeCoy) are: Specimen USNl\I 161040 appea.rs to be the most highly "That the septa may be dilated at the margin of the evolved speei1nen of Oorwenia in the eollection. It has tabularium in all quadrants is shown in figure 12 of more elosely spaeed inner tabellae and also well Smith, 1916, pl. 21, a section of the ephebic. stage of a developed septal and dissepithecal stereozones. Thus, of specimen of Oonvenia rugosa from the type-locality. A all the speeimens, it shows the elosest relationship to section of an earlier stage of the same coralhun * * * the genus H erit8chioides Yabe. shows likewise a slight dilation of the septa and the The holotype, LTSNM 161034, reveals in its larger presenee of a dissepitheca. ~' These two eharaeteristies, corallites most. of the eharacteristics of specimen the development of stereozones on the septa and dis USNl\1: 161040 and in its smaller eorallites most of the sepitheca, are the pri1nary reasons why Yabe (1950) set eharaeteristics of speeimen lTSNM 160534. The material up the genus lleritschioides, whose type speeies is Oor now available for study indicates that all the ;:;pecimens wenia columbica (Smith, 1935) \vhich is from the of Oor1Denia from the Wahoo Limestone probably rep Pennsylvanian or Permian beds of British Columbia. resent one speeies. Further collecting of large numbers Minato and l(a.to (1965, p. 31), in their redescription of of Oo·J'wenia from the \Yahoo Limestone 1nay permit the genus 0 orzcenirt as contrasted to the genera of their the differentiation of one or more species. new fa1nily Durha1ninidae whieh ineludes H eritschi None of the deseribed species of corals from the oides, state "the axial structure of Oorzvenla is quite Cordilleran region of North Ameriea are closely related eharaeteristic, in \vhich septal lamellae are firmly united Ol' similal~ to Oorwen ia jagoen.rsis n. sp. vVaagenophyl with the prolong,ation of axial ends of major septa. lwn columbicwn Smith (1935 1 p. 38) frmn the· Permian Further, cardinal and counter septa are also directly or Pennsylvanian of British Columbia differs in a sig united with Inedium plate. Aecordingly, the axial strue nificant number of eharaeteristies; its eorallites have a ture in 0m'1.venia is quite regulady constructed by diameter of 10-17 mm, 25 major sept•a and long minor radially arranged septal lamellae and a few concentric septa, and upward-sloping tabellae. Tlw tabellae are ally arranged axial tabulae." The fascieulate eorals more densely paeked together than in 0. jagoensis and from the \:Yahoo Limestone have well-developed form a well-developed and wider clisiophylloid eohunellae fonned by the cardinal and counter septa strueture. ·and have dilated n1ajor septa in the tabularium and Oorwenia sym,rnetr2~ca (Dobroljubova) from the \vell-developed dissepitheea (pl. 11 figs. 1---!). The \Vahoo upper ~1oseovian of the Moscow and Donetz basins of Limestone specimens differ from the type species of the lTSSR (Fomiehev, 1953, p. 396) and Groot's (1963, HeJ·ibschioides, H. columbica (Smith), in having less p. 69) speci1nens frmn similar age beds of Palencia, well-defined inner and outer series of tabulae. Fur Spain, have diameters of 5-9 mn1 with 16-20 major thermore, the tabulae in the \Vahoo Limestone speei septa, long minor septa, and weakly dilated n1ajor septa mens are relatiYely widely spaced in contrast to the near the Inargin of the tabularium. C. synunetrica is elosely spaced inner tabellae of H eritschioides colwn dose 1norphologically to 0. jagoenfSi:s n. sp. The latter bica. species differs primarily in having shorter n1inor septa 14 PENNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA and a colonial habit which forms coralla composed of closely spaced corallites (fig. 9). The Eurasian species, Stratigraphic USNM catalog No. Corallum section fragment (em) in contrast, is, frmn the descriptions given by Dobrol jubova (1937, p. 58) and Fomichev (1953, p. 394), a 69A-1 ______160528 Holotype ____ _ 12X 12X 18 solitary or weakly cmnpound form. 69A-1 ______160525 Paratype ____ _ 69A-1 ______4X 4X 5 Oorwenia longisepta (Fomichev, 1953, p. 396) is a 160526 _____ do ______5X 7X 7 69A-1 ______160527 _____ do ______6X 7X 9 species frmn the upper Moscovian of the Donetz basin, 68A-3 ______160529 _____ do ______69A-2 ______7X 14X 15 1TSSR. Groot (1963, p. 69) describes her specimens, 160530 _____ do ______4X 6X 7 69A-2 ______160531 4X lOX 11 fron1 similar age beds in Palencia, Spain, as having 24- 69A-2 ______160532 6X 7X 8 26 major septa in a corallite diameter of 9 mm. It differs from 0. jagoernsis in having longer 1ninor septa and major septa which generally reach the axial region. Transverse thin sections Longitudinal thin sections Name.-The specific name is derived from the Jago (2"X3") (2"X3") Stratigraphic section ------River, which heads at a glacier in the Romanzof Moun Number of Number of Number of Number of thin sections corallites thin sections corallites tains and flows northward into the Arctic Ocean. 69A-l ______1 17 1 5 Family Lons,daleiidae Chapman, 1893 69A-l ______1 7 2 10 69A-l______2 16 2 5 Genus LITHOSTROTIONELLA Yabe and Hayasaka, 1915 69A-l ______1 8 1 7 68A-3 ______1 32 1 4 Lithostrotionella Yabe and Hayasaka, 1915, Geol. Soc. Tokyo 69A-2 ______1 12 1 7 69A-2 ______Jour., v. 22, p. 94. 1 14 1 6 69A-2 ______1 15 1 5 Lithostrotionella Yabe and Hayasaka. Hayasaka, 1936, Taihoku Imp. Univ., Formosa, v.13, no. 5, p. 47-58. Petalaxis Edwards and Haime. Fomichev (part), 1953, Vses. Nauchno-Issled. Geol. Inst. Trudy, p. 449--452. Description.-The holotype, USNM 160528, is a ceri Lithostrotionella Yabe and Hayasaka. Hill, 1956, in Moore, oid corallmn, about 28 em in diameter and 16 em in R. C., ed., Treatise on invertebrate paleontology, Part F, depth, that is shaped like a flattened cone. Geol. Soc. America, p. F306-307. The corallites, 5-8 111m in diameter, have 19-23 long Type species.-LithostJ•otionella wnicu/ln Yabe and sinuous major septa (fig. 10) that are slightly dilated in Hayasaka, 1915, Perinian, Chihsia Limestone,·Yun-nan, the tabularium. Most of the major septa are continuous South China. throughout the dissepimentarium; generally no more than one or two major septa are discontinuous in any Diagnosis.-Cerioid corallum, prismatic corallites, corallite. The cardinal and counter septa are commonly columella a persistent vertical lath frequently continu continuous with the elongate, thin columella. Serial sec ous with counter and cardinal septa. Lonsdaleoid dis tions indicate that the septa are high ridges on the sepiinents. All major septa intermittently reach the upper surfaces of the tabulae. In transverse section, the wall along the tops of the dissepi1nents. Minor septa upward-arched tabulae and the major septa produce a short. Tabulae frequently complete, conical. (Summar spiderweb patteril around the columella (pl. 7, fig. 1). ized from Y abe and Hayasaka, 1915, p. 94). The minor septa are short, generally le,ss than 1 mm Lithostrotionella wahooensis n. sp. long. They are discontinuous in the dissepimentarium and comn1only occur as a series of short ridges on the Plate 5, fig. 1; plate 6, figs. 1-5; plate 7, figs. 1-3 axial sides of the dissepiment walls. The major and 1Jf ateriaZ.-Fraginents of e,ight coralla are available minor septa near their junctions with the corallite wall for study. The coralla are, by Lisburne Group coral are 80-110 microns thick. The microstructure of the standards, small, generally less than 25 em in diameter. holotype has been obscured by the growth of calcite Most colonies are preserved in a pale-gray to a grayish crystals. The individual calcite crystals which form the red-purple chalcedony; however, parts of some coralla corallite walls and septa are now 8-15' microns in size. have some corallites preserved in calcite. All the speci Petrographic studies suggest the microstructure was mens were studied in 2- by 3-inch thin sections and pol fibrous. The major septa on the axial side of the tahula ished slabs. The material available for study is shown rimn wall are 80-150 ·microns thick and taper towards in the following tabulation. their distal ends. The columella typically is 100-150 SYSTEMATIC PALEONTOLOGY 15 11 EXPLANATION Stratigraphic 10 USNM Symbol section Catalog No. Type 0 69A-1 160525 Paratype 9 X 69A-1 160527 Do. 69A-1 160528 Holotype + 68A-3 160529 Paratype 8 + 7 6 5 (J) a: w 4 1- w ~ _J :::! ~ 3 ~ ci w 1- 2 w 11 ~ <( EXPLANATION 0 Stratigraphic USNM w Symbol section Catalog No. ~ 10 _J _J 69A-2 160530 <( a: 0 + 69A-2 160531 9 u 0 69A-2 160532 8 7 6 5 4 3 2 11 12 13 14 15 16 17 18 19 20 27 NUMBER OF MAJOR SEPTA FIGURE 10.-Corallite diameter and number of major septa in Lithostrotionella wahooensis n. sp. 16 PIDNNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA microns thick, has a central band 10 1nicrons thick, and These fossils are characteristie of microfauna! assenl is eomposed of dense fibrous calcite. The wall between blage zone 21, Atoka age, Middle Pennsylvanian. two corallites, 150-200 microns thick, has a dark~ dense Rmnarks.-L£thostrot-ionella wahooemw is differen central band 10-20 1nicrons thick and appears to be tiated from the various species of Meramec and early forn1ed of fibrous calcite (pl. 7, figs. 1, 2). The internal Chester (Late Mississippian) age Li.thostrotionella voids of the corallum are filled by two phases of crys found in the underlying Meramec age Alapah Lime tal growth. The first phase lined all interior surfaees stone and Kayak ( ?) Shale by the development of a with 25- to 50-micron-size crystals of sparry calcite; the n1ore complex tabularimn with a tendency toward inner second phase filled the voids with chalcedony. and outer zones of tabulae. Longitudinal sections show the dissepimentariun1 to Groot (1963, p. 85-86, pl. 18, fig. 2) describes Litho be formed by three to four rows of globose dissepi strotionella orboen&i& Groot fron1 the upper Moscovian ments 0.5 111n1 wide to 1.5 nun long. The tabulae are com Orbo Limestone of Palencia, Spain. L. 01'boensi8 has monly incmnplete; the outer series slope upwards at some characteristics in common with L. 1lJahooen8i8 but angles of 30°-40° frmn the horizontal, the inner series differs in having two to three fewer major septa per slope upwards at angles of 45°-60° frmn the horizontal. corallite, better developed and larger lonsdaleoid dis Petrographic studies of the cohunella indicate that it is sepiinents and, in the tabularium, longer minor septa. for1ned by the axial ends of the 1najor septa. The tabu Also in transverse section the tabularium is not as well lae and dissepiments in seetion are 15-20 n1icrons thick differentiated into zones of inner and outer tabulae as in and are con1posed of dark, dense, 8- to 10-Inicron-size the Alaskan species. crystals of calcite. Petalawi8 1nohikana Fmnichev (1953, p. 459-462) Paratypes lTSNM 160525 and 160527 were collected fron1 the upper Moscovian of the Donetz. Basin, USSR, 3 feet stratigraphically above the holotype and are very is similar in transverse section to L. wa.hooen&is but dif similar in 1norphological details and preservation to the fers primarily in having somewhat smaller corallites holotype (fig. 10). with only 13 or 14 major septa and complete tabulae. The three speci1nens fron1 the Wahoo Limestone of Narn,e.-The specific name is derived frmn the Wahoo the Shublik Mountains, USNM 161030, 161031, and Li1nestone. 161032, are preserved in chert nodules. In general these coralla display a thicker somewhat n1ore massive colu GRAPHIC REGISTRY OF STRATIGRAPHIC mellae, longer septa, and three to five more 1najor septa SECTIONS AND FOSSIL LOCALITIES per corallite (fig. 10) than the holotype. This report is primarily concerned with the Pennsyl Paratype USNM 160529 (pl. 6, fig. 5) is similar to the vanian carbonates and corals of the Lisburne Group. holotype except that the columellae are less well devel The Lisburne Group also includes in this area the Late oped and the tabulae display a tendency to\vards being Mississippian Alapah Limestone, whieh is not discussed cmnplete and not as strongly arched upwards to meet in this report. Sections 68A-1, 69A-1, and 68A-4A-4B the columellae. The specimen is preserved in a chert from the Wahoo Limestone, which are described and nodule. graphically illustrated (fig. 1), are underlain by con Oconrrence.-The holotype USNM 160528 and para siderable thicknesses of Mississippian carbonates. The types lTSNM 160525, 160526, and 160527 are from the 1nicrofossil zonation and lithologies of these older ear upper part of the "'Vest Sadlerochit Mountains section bonates are deseribed by Armstrong, :Ma1net, and Dutro 69A-1, "'V ahoo Limestone (figs. 1, 2). Paratype USN~1 (1970). Section 68A-3 in the central Sadlerochit Moun 160529 is from measured section 68A-3 near the 1niddle tains is structurally complex and is not described in this of the Sadlerochit Mountains (fig. 15), and l_TSNM report. (See Armstrong and others, 1970, fig. 4.) The 161030-161032 are from within an undescribed section vVest Shublik Mountains section, 69A-2, which has (69A-2) at the west end of the Shublik Mountains yielded a nmnber of specimens of Lithostrotionella (fig. 16). 'Wa1woensis n. sp., is badly faulted and has not previ Lithostrotionella walwoensis n. sp. has been found ously been described; detailed stratigraphic description only in the upper part of the "'Vahoo Limestone, in or stratigraphic illustrations of it are not given in this grain-supported high-energy packstones and grain report. stone that are associated with bedded oolites. Micro Reiser, Dutro, Brosge, Annstrong, and Detterman's fossils found with Litlwsfl'otionella wahooensis n. sp. (1970) geologie maps of the Sadlerochit Mountains are Endothyra of the group E. 1nosquensis Reitlinger~ give. detailed ( 1 : 63,360 seale) geologic settings for see lllillo'ella spp., Neoarchaedi8CU8 grand is (Reitlinger), tions 69A-1~ 68A-4A-4B, and 68A-3. Figures 11 GlimacanMnina cf. C. moelleri Reitlingei\ Eo8chuber through 16 are detailed graphic locations of the meas tella sp., P8eudmstaffella sp., and Globit•alt•ulina sp. ured stratigraphic seetions of this report. GRAPHIC REGISTRY OF STRATIGRAPHIC SECTIONS AND FOSSIL LOCALITIES 17 TlS w I' N 0:: 4 3 2 1 35 36 31 32 T4N T3N 9 10 11 12 2 1 6 5 68A-4B )... '( 0 !:.875ft 68A~4A 16 15 14 13 11 12 7 0 8 ~prox1mate locat1on T700 tt Shell 011638-801 68A-1lo 0 21 22 23 24 14 13 18 17 28 27 26 25 23 24 19 20 w w w I' 0 N (¥) ;:; 0:: TlS 0:: 0:: FIGURE 11.-Ikiakpuk River section 68A-1. FIGURE 13.-East Sadlerochit Mountains sections, 68A-4A-4B, and approximate location of Shell Oil Co. section 63B-801 from which paratype, USNM 160537, Oorwenia jagoensis, was collected. T3N 11 12 7 8 36 31 32 33 T3N T2N 14 13 18 17 1 6 5 4 .,.600 ft 69A-~ 23 24 0 19 20 12 7 8 9 26 25 30 29 268A-5 13 18 17 16 1250 ft 35 36 31 32 w w LD lO 24 19 20 21 N N w w 0:: 0:: T3N 00 CJl (¥) (¥) 0:: 0:: FIGURE 12.-West Sadlerochit Mountains section, 69A-1. See figure 2 for a photograph of the outcrop FIGURE 14.-Egaksrak River section 68A-5. See fig and fossil locality. ure 4 for an outcrop photograph. 18 PBNNSYLVANIAN CARBONATES, PALEOECOLOGY, AND RUGOSE CORALS, ARCTIC ALASKA T3N T2N w LD 11 12 7 8 8 9 10 11 N 0:: 14 13 18 17 17 16 15 14 ot 23 19 20 20 21 22 23 /68A-3 f I. Location of L. wahooensis 69A-~ ~Location of 1200 t""' coral collect1ons L. wahooensis coral collect1ons 26 25 30 29 29 28 27 26 w LD 35 36 31 32 32 33 34 35 N w w 0:: I' co N N 0:: 0:: T3N T2N FIGURE 15.-Central Sadlerochit Mountains section FIGURE 16.-West Shublik Mountains section 69A-2. 68A-3. This section is not discussed in detail in This section is not discussed in detail in this this report. report. SELECTED REFERENCES Armstrong, A. K., 1967, Biostratigraphy and carbonate facies ---1971, Hsburne Group, Cape Lewis-Niak Creek, north of the Mississippian Arroyo Penasco Formation, north western Alaska, in Geological Survey research 1971 : U.S. central New Mexico: New Mexico Bur. ~fines and Mineral Geol. Survey Prof. Paper, 750-B, p. B23-B34. Resources Mem. 20, 80 p., 10 pls., 45 figs. Ball, M. :\1., 1967, Carbonate sand bodies of Florida and the ----1970, Carbonate facies and the lithostrotionid corals of Bahamas: Jour. Sed. Petrology, v. 37, no. 2, p. 55~91, the ~1ississippian Kogruk Formation, DeLong :\fountains, figs. 1-40. northwestern Alaska: U.S. Geol. Survey Prof. Paper 664, Ball, M. ~I., Shinn, E. A., and Stockman, K. W., 1967, The geo~ 38 p., 14 pls., 37 figs. logic effects of Hurricane Donna in south Florida : Jour. Armstrong, A. K., MacKevett, E. M., Jr., and Silberling, N. J., Geology, v. 75, no. 5, p. 583-597, 14 pls., 2 figs. 1969, The Chitistone and Nizina Limestones of part of the Bo·wsher, A. L., and Dutro, J. T., Jr., 1957, The Paleozoic sec southern 'Vrangell Mountains, Alaska-A preliminary re tion in the Shainin Lake area, central Brooks Range, port stressing carbonate petrography and depositional en Alaska: U.S. Geol. Survey Prof. Paper 303-A, 39 p., 6 pis., vironments, in Geological Survey Research 1969: U.S. Geol. 4 figs. Survey Prof. Paper 650-D, v. D49-D62, 9 figs. Brosge, ,V. P., Dutro, J. T., Jr., Mangus, M. D., and Reiser, Armstrong, A. K., and l\famet, B. L., 1970, Biostratigraphy and H. N., 1962, Paleozoic sequence in eastern Brooks Range, dolomite porosity trends of the Lisburne Group, in Adkison Alaska: Am. Assoc. Petroleum Geologists Bull., v. 46, no. 12, W. L., and Brosge, M. M., eds., Proceedings of the geologi p. 2174-2198. cal seminar on the North Slope of Alaska: Los Angeles, Cloud, P. E., Jr., 1955, Physical limits of glauconite formation: Pacific Sec., Am. Assoc. Petroleum Geologists, p. N1-N16, 12 Am. Assoc. Petroleum Geologists Bull., v. 39, no. 4, p. 482- figs. 492. Armstrong, A. K., Mamet, B. L., and Dutro, J. T., Jr., 1970, Coogan, A. H., 1969, Recent and ancient carbonate cyclic se Foraminiferal zonation and carbonate facies of Carbon quences, in Elam, J. G., and Chuber, S., eds., Symposium on iferous (Mississippian and Pennsylvanian) Lisburne Group, cyclic sedimentation in the Permian Basin (1967) : West central and eastern Brooks Range, Arctic Alaska : Am. Texas Geol. Soc. Pub. 69-56, p. 5-27, 6 figs. Assoc. Petroleum Geologists Bull., v. 54, no. 5, p. 687-698, 4 Detterman, R. L., 1970, Sedime-ntary history of the Sadlerochit figs. and Shublik Formations in northeastern Alaska, in Adkison, SIDLECTED REF1ERENCES 19 W. I.~., and Brosge, M. M., eds., Proceedings of the geologic Reiser, H. N., Dutro, J. T., Jr., Brosge, W. P., Armstrong, A. K., seminar on the north slope of Alaska : Los Angeles, Pacific and Detterman, R. L., 1970, Progress map, geology of the Sec. Am. Assoc. Petroleum Geologists, p. 01-013, 9 figs. Sadlerochit and Shublik Mountains: U.S. Geol. Survey Dobroljubova, T. A., 1937, Simple corals of the Myatshkova and open-file map, scale 1 :63,360. Podolsk horizons of the Middle Carboniferous of the Mos: Roehl, P. 0., 1967, Stony Mounta.in (Ordovician) and Interlake cow basin : Paleozool. Inst. Trudy, v. 7, no. 3, 92 p. [in (Silurian) facies analogs of Recent low-energy marine and Russian]. subaerial carbonates, Bahamas·: Am. Assoc. Petroleum Dunham, R. J., 1962, Classification of carbonate rocks accord Geologists Bull., v. 51, no. 10, p. 1979-2032. ing to deposition texture, in Classification of carbonate Shinn, E. A., 1968a, Practical significance of birdseye structures rocks-a symposium : Am. Assoc. Petroleum Geologists in carbonate rocks: Jour. Sed. Petrology, v. 38, no. 1, p. 215- Mem. 1, p. 108-121. 223, figs. 1-13. Fischer, A. G., 1964, The Lofer cyclothems of the Alpine Trias ---1968b, Burrowing in recent lime sediments of Florida and sic, in Merriam, D. F., Symposium on cyclic sedimentation: the Bahamas: Jour. Paleontology, v. 42, no. 4, p. 879-894, Kansas Geol. Survey Bull., v. 169, no. 1, p. 107-149. pls. 109-112, figs. 1-17. Fomichev, V. D., 1953, Coral Rugosa and stratigraphy of the Shinn, E. A., Ginsburg, R. N., and Lloyd, R. M., 1965, Recent Middle and Upper Carboniferous and Permian deposits of supratidal dolomite from Andros Island, Bahamas, in Dolo the Donetz basin: Vses. Nauchno-lssled. Geol. Inst. Trudy, mitization and limestone diagenesis-A symposium: Soc. 622 p., 44 pls. [in Russian]. Econ. Paleontologists and Mineralogists Spec. Pub. 13, Fri.edman, G. M., 1959, Identification of carbonate minerals by p.112-123. staining methods: Jour. Sed. Petrology, v. 29, no. 1, p. 87-97. Smith, Stanley, 1916, The genus Lonsdaleia and Dib'Ltnophyllum Groot, G. E., de, 1963, Rugose corals from the Carboniferous of rugosum (McCoy) : Geol. Soc. London Quart. Jour., v. 71, northern Palencia (Spain) : Leidse Geol. Meded., pt. 29; 123 p. 218-272, pl. 21, figs. 3-16. p., 26 pis., 39 figs. ---1935, Two anthracolithic corals from British Columbia Hill, Dorothy, 1938-1941, The Carboniferous rugose corals of and related species from the Tethys: Jour. Paleontology, Scotland : Palaeontogra.phical Soc. Mon. [London], 1938, pt. v.9,no.l,p.30-42,pls.8,9. 1, p. 1-78 (v. 91), 2 figs., 2 pis.; 1939, pt. 2, p. 79-114 (v. 92), Smith, Stanley, and Ryder, T. A., 1926, The genus Corwenia 3 pis. ; 1940, pt. 3, p. 115-204 ( v. 94) ; 1941, pt. 4, p. 205-213 gen. nov.: Annals and Mag. Nat. History, v. 17, no. 9, p. (v. 95). 149-159, pls. 7, 8. ---1956, Rugosa, in Moore, R. C., ed., Trerttise on invertebrate Wilson, J. L., 1967a, Cyclic and reciprocal sedimentation in Vir paleontology, Part F., Coelenterata: Geol. Soc. America and gilian strata of southern New Mexico: Geol. Soc. America Kansas Univ. Press, p. F233-F324. Bull., v. 78, no. 7, p. 805-817, 4 pls., 4 figs. Kato, Makoto, 1963, Fine skeletal structures in rugosa: Hok ---1967b, Carbonate-evaporite cycles in lower Duperow kaido Univ. Fac. Sci. Jour., ser. 4, v. 11, no. 4, p. 571-630, Formation of Williston basin: Canaman Petroleum Geology, 3 pis., 19 text figs .. v. 15, no. 3, p. 230-312, 22 pls., 14 figs. Lochman-Balk, Christina, 1957, Paleoecology of the Cambrian ---1969, Microfacies and sedimentary structures in "deeper in Montana and Wyoming, chap. 8 of Ladd, H. S., ed., Pale water" lime mudstones, in Friedman, G. M., ed., Depositional oecology: Geol. Soc. America Mem. 67, p. 117-162, 1 pl., 7 environments in carbonate rocks-A symposium: Soc. Econ. figs. Paleontologists and Mineralogists Spec. Pub. 14, p. 4-19. Logan, B. W., Rezak, R., and Ginsburg, R. N., 1964, Classifica. 'Vilson, J. I.~., Madrid-Solis, A., and Malpica-Cruz, R., 1967, tion and environmental significance of algal stromatolites: Microfacies of Pennsylvanian and Wolfcampian strata in Jour. Geology, v. 72, no. 1, p. 68-83, 5 figs. southwestern U.S.A. and Chihuahua, Mexico, in New Mexico Minato, Masao, and Kato, Makoto, 1965, Durhaminidae (Tetra Geol. Soc. Guidebook 20th Field Conf. : p. 80-90, 4 pls., 3 figs. coral) : Hokkaido Univ. Fac. Sci. Jour., ser. 4, v. 8, no. 1, 86 Yabe, H., 1950, Permian corals resembling Waagenophyllum and p., 5 pls., 24 figs. Corwenia: Japan Acad. Proc., v. 26, no. 2-5, p. 74-79. Murray, R. C., and Lucia, F. J., 1967, Cause and control of dolo Yabe, H., and Hayasaka, Ichiro, 1915, Palaeozoic corals from mite distribution by rock selectivity: Geol. Soc. America Japan, Korea, and China: Geol. Soc. Tokyo Jour., v. 22, no. Bull., v. 78, p. 21-35. 264, p. 93-109. INDEX [Italic page numbers indicate major references] Page Page Page Alapah Limestone ______3, 4, 10,16 Foraminifera ______5, 9 Ooids______5, 7 Algae, calcareous______5, 9 Fossil localities, registry ______16 Orbo Lime,stone ______• __ 16 Arctic Ocean______14 orboensis, Lithostrotionella______3,16 Fasulinella sp______3 Aulophyllidae______10 Fusulinids ______Osagia sp ______. ______------___ 5, 8 Bahama Banks______g Glauconite______5, 7 Palencia, Spain.------13, 14,16 Biostratigraphy ___ -----______3 Glauconite formation______7 Pelletoidal-bioclastic-grainstones and pack- Brachiopods______6, 9 Globivalvulina sp ______3, 13,16 stones, Alapah Limestone ______British Columbia______13 grandis, Neoarchaediscus ______3, 13,16 Petalaxis______14 Bryozoans ______------______Graphic registry of stratigraphic sections and mohikana______3,16 Bryozoan-crinoid wackestones and packstones, fossil localities.______16 Previous work and acknowledgments. ______3 Wahoo Limestone______4, 5 Groot, G. E., cited ______10, 13, 14,16 Profusulinella sp ______------3 Bryozoan-e,chinoderm packstones, Wahoo Pseudostajfella sp ______3, 13,16 Limestone.______4 Heritschioides______13 Bryozoan-echinoderm packstones and wacke- columbica ______• ______13 Romanzof Mountains ______. ______. 14 stones, Alapah Limestone ______rugosa, Corwenia ______. __ _ 13 Bryozoan-echinoderm wackestones and pack- lkiakpuk Creek ______Lonsdale Ia. ______. _. ____ -___ -_--- __ 10 stones, Wahoo Lime,stone______5, 7 Ikiakpuk Creek section ______5, 6,12 Rugose corals, adaptation_------10 Alapah Lime,stone______3 environments ______.------.----.------9 Carbonate depositional megacycle______6, 7 Introduction ______Carbonate stratigraphy______3 Sadlerochit Formation______4,6 Cherty dolomite, Alapah Limestone ______Ja~o River______14 Echooka Member ____ ------6 Chihsia Limestone,______14 jagoensis, Corwenia ______3, 9, 10 Sadlerochit Mountains. ______3, 5, 6, 7,16 Climacammina moellerL ______3, 13,16 Schindler, Stanley F., cited______12 columbica, Corwenia______13 Selected refe,rences ______------18 Heritschioides______13 Kato, Makoto, quoted______13 Kayak(?) Shale______6, 16 Shublik Mountains. ______5,16 columbicum, Waagcnophyllum______13 Corwenia______10 Kogruk Formation______10 Stratigraphic sections, registry------____ ---- 16 symmetrica, Coru·enia ______3,13 columbica______13 Systematic paleontology _____ ------10 jagoensis ______3, 9, 10 Lipinella sp ___ ------3,13 longisepta______14 Lisburne Group ______3, 7, 10,16 unicum, Lithostrotionella______14 rugosa______13 biostratigraphic zones______3 symmetrica______3,13 Lithology, Alapah Limestone. ______JVaagenophyllum columbicum______13 Wahoo Limestone._------4, 5, 6 Lithostrotionella______14 Wachsmuth Limestone .. ______------3 DeLong Mountains______10 orbocnsis______3,16 Wahoo Lake______3 Donetz Basin, U.S.S.R ______3,13,14,16 ·unicum______14 wahoo Limestone ______3, 4, 7, 9, 12, 13,16 Durhaminidae______13 wahoocnsis ______3, 9,14 colonial coral assemblage ______- ___ - 9 Dvinella sp ______------13 coral paleoecology ______------9 Longisepta, Corwenia ___ _------14 Lonsdaleiidae. ______----- _------dolomites ______------8 14 oolite marker beds ______East Sadlerochit Mountain section ______5, 6,12 Lonsdaleia rugosa ______----_--- 10 \Vahoo Limestone ____ ------4 oolitic grainstone ______---_------5, 8 Echinoderm-bryozoan packstone s-w aek e- type section______3 stones______8 Mamet, B. L., rited______3 wahooensis, Lithostrotionella ______3, 9,14 Millerella sp ______3, 13,16 Echinoderms______9 We,st Sadlerochit Mountain section ______6,16 Minato, Masao, quote,d______13 Egaksrak River section ______8,12 Alapah Limestone ______------3 moelleri, Climacammina ______3, 13,16 Wahoo Limeston~------5 Wahoo Limestone_------4 Endothyra ______3, 13,16 mohikana, Petalaxis______3,16 West Shublik Mountains section ______16 mosquensis ______3, 13,16 mosquensis, Endothyra_ ------3, 13,16 Wilson, James L., quoted______8 Environments of de,position______6 Eoschubertella sp ______3, 13,16 Neoarchaediscns grand is ______3, 13,16 Yun-nan, South China______14 21 0 U.S. GOVERNMENT PRINTING OFFICE: 1973 0- 467-564 PLATES 1-8 [Contact photographs of the plates in this report are available, at cost, from the U.S. Geological Survey Library, Federal Center, Denver, Colo. 8022·5] PLATE 1 FIGURES 1-6. Corwenia jagoensis n. sp. USNM 161034, holotype. 250 feet below the top of East Sadlerochit Mountains section 68A-4A-4B, Wahoo Limestone, Atoka age. 1-3. Transverse thin sections, X 25. 1, Arrows point to the well-developed dissepitheca and dilated septa. 2, Illustrates the differing micro structure of the septa and corallite wall, the dilated septa, and dissepitheca. 3, View of the axial region showing lath shape and microstructure of the columella (C) which is continuous with cardi nal and counter septa, septal ridges (S) on upper surfaces of tabulae, and aulophylloid axial structure. 4. Longitudinal thin section, X 25. View of corallite wall microstructure, dissepimentarium, and (D) junction of dissepitheca and tabellae . .5-6. 5, Longitudinal thin section, X 3; replacement by chalcedony obscured lower part of corallite and some of the dissei)imentarium. 6, Transverse thin section, X 3. GEOLOGICAL SURVEY PROFESSIONAL PAPER 74 7 PLATE I 2 4 3 PLATE 2 FIGURES 1- 5. Corwenia jagoensis n. sp. 1- 3, 5. 1-3, Longitudinal thin sections, X 3. 5, Transverse thin section, X a, holotype, USNM 161034; 250 feet below the top of the East Sadlerochit Mountain section 68A-4A-4B, Wahoo Limestone. 4. Longitudinal thin section, X 3, paratype, USNM 161038; 270 feet below the top of the Egaksrak River ~ection 58A-5, Wahoo Limestone. GEOLOGICAL SURVEY PROFESSIONAL PAPER 747 PLATE 2 CORWENIA JAGOENSIS n. sp. PLATE 3 FIGunr:s 1-4. Corweniajagoensis n. sp. 1. Tran~v e r se thin section, X 3, holotype, USNM 161034; 250 feet below the top of the East Sadlerochit Mountain section 68A-4A, Wahoo Limestone. 2- 4. 2, Longitudinal thin section, X 3. 3, 4, Transverse thin sections, X 3, paratype, USNM 161038; 270 feet below the top of the Egaksrak River section GSA-5, Wahoo Limestone. 2 CORWENIA JAGOENSIS n . sp . PLATE 4 FIGURES 1-4. Corwenia jagoensis n. sp. 1. Transverse t hi n section, X 3, paratype, USNM 160537; 150 feet below the contact of the Wahoo Limestone and Sadlerochit Form ation. One and one-fourth m ile west of section 68A - 4A. 2, 3. Transverse thin sections, X 3, paratype, USNM 161039; 230 feet below the top of the Egahrak River section 68A-5. Wahoo Lime stone. 4. Transverse thin section, X 3, paratype, USNM 161040, near Salis bury Mountain, Wahoo Limestone. GEOLOGICAL SURVEY PROFESSIONAL PAPER 747 PLATE 4 CORWENIA JAGOENSIS n. sp. PLATE 5 FI:>URE 1. Litho;trotionella wahooensis n. sp. 1. Transverse thin section, X 3, paratype, USNM 160527; 50 feet from the top of the Wc;;t Sadlerochit Mountains section 69A-1, Wahoo Limestone. 2-4. Corwenia jagoensis n . ;;p. 2. Longitudinal thin section, X 3; 3, 4, Transverse thin sections, X 3, paratype, USNM 161040; near Sali sbury Mountain, Wahoo Limestone. GEOLOGICAL SURVEY PROFESSIONAL PAPER 747 PLATE 5 1 2 ·--"'"""""';.:=,IJ•,.,..,-~...:-rc"/~~IJf"""' 3 4 LITHOSTROTIONELLA WAHOOENSTS n. sp . and CORWENTA JAGOENSTS n. sp. PLATE 6 ·FIGURES 1-5. Lithostrotionella wahooensis n . sp. 1-3. 1, Transverse thin section, X 3; 2,3, Longitudinal thin sections, X 3, holotype, USNM 160528; 48 feet below the top of the West Sadler ochit Mountains section 69A-1, Wahoo Limestone. 4. Transverse thin section, X 3, paratype, USNM 160530; Wahoo Lime stone, West Shublik Mountain section 69A- 2. D . Transverse thin section, X 3, para type, USNM 160529; upper 75 feet of the Wahoo Limestone, Sadlerochit Mountains section 68A-3. GEOLOGICAL SURVEY PROFESSIONAL PAPER 74 7 PLATE 6 2 3 LITHOSTROTIONELLA WAHOOENSIS n. sp .. PLATE 7 FIGURES 1-3. Lithostrotionella wahooensis n. sp. 1-2. Transverse thin sections, X 25. 1, Axial region illustrating microstructure of columella which is continuous with the sinuous cardinal and counter septa. 2, Microstructure of the corallitc wall, with its dark central band, and of the sinuous major septa and discontinuous minor septa. The structures of the corallum are preserved as calcite, the internal voids of the corallum are filled by clear, colorless, transparent chalcedony. Holotype, USNM 160528; 48 feet below the top of the West Sadlerochit Mountain section 69A-l. 3. Transverse thin section, X 25; corallum is preserved within a chert nodule. The microstructure of the corallites is preserved by a red jasper chalcedony, whereas the internal voids are filled with a clear chalcedony. Para type, USNM 160529; upper 75 feet of the Wahoo Limestone, Sadlerochit Mountain section 68A-3. 4-5. Section 69A-1, West Sadlerochit Mountains, Wahoo Limestone. 4. Pelletoid to rounded micritic lithoclasts, bryozoan grainstone. Note the fine abraded bioclastic inclusion within the micritic lithoclasts. X 25; 65 feet from top of section. 5. Crinoidal-bryozoan-algal wackestone and packstone. Bioclastic fragments arc finely abraded and broken; texture of rock suggests extensive burrowing. X 25; 150 feet from top of section. 6-8. Section 68A-4A-4B, East Sadlerochit Mountains, Wahoo Limestone. 6. Ooid foraminiferal grainstone. The centers of the ooids arc Foraminifera, broken and rounded fragments of echinoderms, bryozoans, and small micritic lithoclasts. X 25; 290 feet from top of section. 7. Ooid-micropelletoid grainstone. Rounded and winnowed fragments of bryozoans, echinoderms, ostracodes, and micritic pellets with, typically, a single oolitic coating; X 25; 490 feet from top of section. 8. Bryozoan-echinoderm-algal packstone. Poorly sorted fossil fragments with micrite filling the voids between the bioclasts. X 25; 570 feet from top of section. GEOLOGICAL SURVEY PROFESSIONAL PAPER 747 PLATE 7 PLATE 8 FIGURES 1-6. Section 68A-5, Egaksrak River, Wahoo Limestone. 1. Pelletoid-bryozoan-echinoderm grainstone. Fossil fragments and pellets are rounded and winnowed; one layer of oolitic coating on pellets and on some rounded bioclasts. X 25, 150 feet from top of section. 2. Oolitic grainstone. Large ooids, 0.6-0.7 mm in diameter, have numerous and thick oolitic layers. Ooids generally have fo ssil fragments for their centers and show evidence of algal borings. Associated with the ooids are abund ant Osagia sp. X 25, 600 feet from top of section. 3. Pellctoid-bryozoan-echinoderm grainstone. Rounded and winnowed bioclasts, with small Foraminifera, Globi valvulina sp. X 25, 430 feet from top of section. 4. Bryozoan-echinoderm-foraminiferal lithoclast packstone and grainstone. Large rounded fossil fragment, micrite lithoclasts, and varying amounts of micrite pore and void filling. X 25, 750 feet from top of section. 5. Bryozoan packstone. Large bryozoan fragments in micrite. Large fossil fragments parallel to bedding suggest deposition in a noncurrent environment. X 25, 830 feet from top of section. 6. Echinoderm-gastropod-foraminiferal-bryozoan packstone and grainstone. Rich, diversified fauna; broken and rounded, but poorly sorted, bioclasts and lime mud, suggesting extensive burrow and weak currents. X 25, 1,130 feet from top. 7- 8. Section 68A-1, Ikiakpuk section, Wahoo Limestone. 7. Tectonically stressed oolitic grainstone. Fossil fragments and oolites have been elongated by tectonic stress and solution; Ooids are ellipsoids. X 25, 20 feet from top of section. 8. Tectonically stressed bryozoan-echinoderm packstone. Note the elongation and grain growth of the crinoid ossicles. Echinoderm ossicles are particularly prone to alteration and elongation due to tectonic stress. X 25, 95 feet from top of section. GEOLOGICAL SURVEY PROFESSIONAL PAPER 747 PLATE 8 5 6 7 8 Photomicrographs of carbonate rock types in sections 68A-5, 68A-1.