U.S. DEPARTMENT OF THE INTERIOR TO ACCOMPANY MAP IÐ2673 U.S. GEOLOGICAL SURVEY

GEOLOGIC MAP OF THE ARCTIC QUADRANGLE, ALASKA

By W.P. Brosgé, H.N. Reiser, J.T. Dutro, Jr., R.L. Detterman, and I.L. Tailleur

INTRODUCTION parts of the quadrangle in 1926 and 1927 and published his results in 1930 (Mertie, 1930). This rapid reconnaissance, GEOLOGIC SETTING AND LAND USE made mostly on foot under extremely difficult conditions, sketched out the rudimentary distribution of rock types, but The Arctic quadrangle is well located to shed light on little of the modern stratigraphy was discerned. The distri- the basic geologic relations of northern Alaska. The rocks bution of the Lisburne Limestone in the eastern part of the represent all of the stratigraphic systems from Cambrian to quadrangle was roughly shown; and the approximate distri- Cretaceous and all but one of the tectono-stratigraphic bution of the Devonian clastic rocks between the East Fork subterranes of the Brooks Range, from the autochthonous of the Chandalar and the Sheenjek valley was also shown subterrane in the north to the allochthonous subterranes far- although details of the history of these strata were not known. ther south. Most of the pre-Mississippian carbonate rocks were mapped Among the distinctive geologic features displayed in the by Mertie as Skajit Limestone, supposedly of Silurian ages. Arctic quadrangle are voluminous volcanic rocks of prob- He mapped the chert and slate unit between Old Woman able Devonian age, a wide array of Carboniferous carbonate Creek and the East Fork of the Chandalar, and tentatively facies in the Lisburne Group (which here extends up into the assigned it a Mississippian or Late Devonian age. This early Middle Pennsylvanian), the southward transition of Upper reconnaissance provided the first geologic and topographic Devonian (Famennian) clastic facies from fluvial conglom- information about the area that is now known as the Arctic erate to marine sandstone, a full display of Upper Devonian quadrangle. (Frasnian) reef-related strata, and fossiliferous Ordovician The first modern work in the quadrangle was done by rocks in both carbonate and chert terranes. W.P. Brosgé, H.N. Reiser, M.D. Mangus, and J.T. Dutro, Jr. Most of the quadrangle is in the Arctic National Wild- in 1952 as a part of a regional reconnaissance of the eastern life Refuge (ANWR) and Arctic Wildlife Refuge Wilderness. Brooks Range made under the aegis of the program for ex- The quadrangle also includes Arctic Village, the only village ploration of Naval Petroleum Reserve No. 4 (see Reed, 1958, in the region and a potential destination or transfer point for p. 156, 157). Work in this quadrangle was concentrated in visitors to the wildlife refuge. the Porcupine Lake area, but a small amount of mapping was done by Mangus and Dutro in the Old Woman Creek HISTORY OF GEOLOGIC MAPPING area. During the 1960’s, Brosgé, Reiser, and Tailleur made This quadrangle geological map is the product of seren- trips of a few days to a month into the Arctic quadrangle dipitous mapping activities of the U.S. Geological Survey. while doing other regional work in northern Alaska. This Although never scheduled as an official project, data from resulted in a 1965 reconnaissance geologic map based, in the Arctic quadrangle have accumulated for more than 40 large part, on photo interpretation. In 1969 and the early years. Geologists involved with the regional geology of the 1970’s, a few outcrops were examined incidental to map- eastern and southern Brooks Range made occasional forays ping in adjacent quadrangles. More detailed studies were into the Arctic quadrangle, usually as adjuncts to projects undertaken in 1972 by Warren Yeend and most of the co- with other emphases. Chief among these geologists were the authors during the production of a geologic strip map of the authors, who were supported at various times by the people corridor for a proposed gas pipeline from Prudhoe Bay to listed in the acknowledgments and on the map itself. The northwest Canada. In 1978 and 1979, work was done on the authors especially thank M.D. Mangus, T.H. Nilsen, T.E. clastic rocks of the Mississippian-Devonian Endicott Group Moore, W. Yeend, C.G. Mull, D.L. Jones, and M. Churkin, as a part of an overall regional restudy by T.H. Nilsen, T.E. Jr. for help in the field and for ideas provided during the Moore, Brosgé, Reiser, and Dutro. In 1979, R.L. Detterman assembly of this map. joined the group for additional fieldwork on the upper Pa- The paragraph at the lower right corner of the map gives leozoic sequence. The month’s field work during August, a brief history of the geologic mapping in the quadrangle; a 1979, was the most concentrated effort to collect geologic bit of elaboration is presented here. The first geologic recon- data in the Arctic quadrangle. Special purpose collecting, naissance of this region was by J.B. Mertie, Jr. who traversed mostly for fossils, was done by several small groups of ge-

1 ologists during the 1980’s, and their data have been incorpo- Sadlerochit groups. The tract is outlined by anomalous con- rated in this compilation wherever relevant. In the late 1970’s, centrations of tin and silver in sediments from streams that the geologic map in almost its present form was compiled drain a large area of the Lisburne Group immediately north by Reiser. After a few weeks of additional fieldwork and the of the fluorite veins. identification of conodont and radiolarian collections in 1982 to 1987, some new interpretations were possible and the fi- ACKNOWLEDGMENTS nal compilation was completed by Brosgé. The authors acknowledge the aid and encouragement of MINERAL RESOURCE AND GEOPHYSICAL SURVEYS a great many colleagues and friends who have contributed to the making of this map. First, are the Native people of Arctic In 1965, a reconnaissance aeromagnetic survey of north- Village who provided hospitality to Mertie in 1926 and 1927 eastern Alaska was flown at altitudes of 2,500 and 5,000 ft, and then to us when we lived there in parts of the summers and line spacings of 4 to 8 mi, with many gaps. It indicated of 1960, 1966, 1972, 1978, and 1979. We especially thank parts of two linear east-west trending positive anomalies in Johnny Frank, who was Mertie’s field assistant in 1927 and the northern part of the Arctic quadrangle, but most of the who befriended us decades later. northwestern part of the quadrangle was not surveyed (Brosgé Most important to the map are all those who provided and others, 1970). basic mapping information and assistance; these people are In 1976, 1977, and 1978, geologists of the U.S. Bureau listed in the paragraph below the lower right corner of the of Mines made a reconnaissance mineral assessment of most map and in the list of contributors of paleontologic data in of the Arctic quadrangle. A geochemical sample survey of table 1. Special thanks go to Marv Mangus, Warren Yeend, stream sediments in about three-fourths of the quadrangle Tor Nilsen, Tom Moore, Gil Mull, Norm Silberling, Mike was augmented by field investigations of mineral occurrences Churkin, Dave Jones, Bonnie Murchey, Bill Oliver, Gus and geochemically anomalous areas. In addition, the geol- Armstrong, Mac Gordon, Bernard Mamet, Serge Mamay, ogy and fluorite showings near Porcupine Lake were mapped Bruce Wardlaw and Ellis Yochelson, and to Karen Adams in detail (Peace, 1979; Barker, 1981). for help in drawing the map. Little or no private mineral exploration has been done Over the years, several supervisors have given us the in the Arctic quadrangle, and little is now likely to be done leeway to complete a wide range of studies in this quad- within the Arctic National Wildlife Refuge. There are no rangle. Foremost among these is George Gryc who, during known mineral deposits, however, the U.S. Bureau of Mines the 1970’s and early 1980’s, provided a research atmosphere reported that several areas are favorable. The two areas cited that fostered optimum scientific results not only for evaluat- for particular attention are a tract in the Devonian shale and ing petroleum reserves in northern Alaska but also for fur- sandstone and underlying lower Paleozoic carbonate rocks thering the general knowledge of Arctic geology. in the southwestern part of the quadrangle, and a tract in the Mississippian to Pennsylvanian carbonate rocks and Permian shale and sandstone near Porcupine Lake in the northwest- TERRANES, SUBTERRANES, AND ern part of the quadrangle. STRATIGRAPHIC SEQUENCES The tract in the Devonian and older rocks is the eastern extension of a more favorable tract in the adjacent Philip Cambrian to Cretaceous rocks crop out in six separate Smith Mountains quadrangle that contained five groups of tectono-stratigraphic sequences in the Arctic quadrangle. claims. Two of these were for zinc and lead in quartz veins Rocks of the same age differ in lithology and environment in the layer of replacement chert that locally caps the lower of deposition from sequence to sequence and may be miss- Paleozoic Skajit Limestone (Detra, 1977). Three were for ing in some sequences. copper in quartz and calcite veins in the top of the Skajit Similar stratigraphic sequences have been recognized and in the clastic sediments of the overlying Devonian throughout most of the Brooks Range. Almost every one of Beaucoup Formation. These suggest the possibility of both those sequences has been given a distinctive stratigraphic Mississippi Valley-type and shale-hosted deposits (Menzie name (see list in Mayfield and others, 1988). In addition, the and others, 1985). structural units in which they occur have been given several Mineralization in the second tract is in veins of fluorite kinds of structural names. Recognized originally as where some tetrahedrite and enargite were found for a strike allochthons, thrust panels, or belts by those who mapped them length of about a mile just below the contact between (Snelson and Tailleur, 1968; Martin, 1970; Mayfield and oth- Lisburne Group carbonate rocks and overlying Sadlerochit ers, 1988; Patton and Box, 1989), they were also described Group shale and sandstone about 2 mi north of Porcupine as terranes or subterranes by Jones and others (1987). Ter- Lake. Fluorite partially replaces some of the limestone and ranes and subterranes are defined as “fault bounded pack- occurs as large lumps of float 1.5 mi farther north where an ages of rock that display internal stratigraphic affinities, and unusual 50Ðft layer of tuff lies between the Lisburne and geologic histories that differ”, and thus form a system that

2 accommodates all the different structural units and the dif- Paleozoic carbonate rocks of the Hammond Subterrane might ferent stratigraphic sequences (Moore and others, 1994a). also be closely related to the carbonate rocks of the Lower Moore and others (1994a) adopted the terrane/subterrane Paleozoic Porcupine Terrane to the southeast of the Arctic nomenclature for all of northern Alaska with some modifi- quadrangle (Dover, 1994). cation of the names used by Jones and others (1987). We Three areas in the Arctic quadrangle are underlain by struc- also use the subterrane nomenclature as a convenient way of tural assemblages of several subterranes. These are: the com- ordering the rocks in the Arctic quadrangle. We use our own bined Endicott Mountains and De Long Mountains Subterranes stratigraphic and geologic definitions for some of the near Porcupine Lake; the Endicott Mountains and Venetie subterrane boundaries, and use some of the local names origi- Subterranes near Nichenthraw Mountain; and the Venetie and nally used by Jones and others (1987). Karl and Mull (1993) Sheenjek Subterranes south and east of the Junjik River. In suggested that the subterrane nomenclature does not con- addition, at the top of the assemblage of subterranes around tribute to geologic understanding, because the boundaries Mount Annette, near Porcupine Lake, are small klippen of Tri- cannot be clearly drawn, and the term subterrane includes assic and Permian volcanic rocks and chert like the rocks of such a variety of structural units. However, this ambiguity is the Tozitna Terrane (Jones and others, 1987) that occur exten- helpful in the Arctic quadrangle, where the different strati- sively just south of the Arctic quadrangle. graphic sequences occur in a variety of structural units, and some of the boundaries are poorly defined. North Slope Subterrane

NAMES AND BOUNDARIES OF THE SUBTERRANES Jones and others (1987) defined the North Slope Subterrane IN THE ARCTIC QUADRANGLE as “Precambrian to lower Paleozoic basement rocks overlain by Kekiktuk Conglomerate (Mississippian)....Lisburne All of the subterranes identified on the map are subdi- Group...Sadlerochit Group and younger Mesozoic strata”. In visions of the Arctic Alaska Terrane as revised by Moore the southern part of the subterrane east of the Arctic quad- and others (1994). The Arctic Alaska Terrane extends from rangle, Anderson (1991b) mapped an additional unit of the south edge of the Brooks Range to the Arctic Ocean, Middle Devonian to Mississippian(?) conglomerate, sand- and includes two subterranes that were originally described stone, and shale that locally rests unconformably on the base- as separate terranes by Jones and others (1987) — the Venetie ment rocks and lies unconformably beneath the Kekiktuk and Sheenjek Subterranes. Three of the subterranes (Endicott Conglomerate. The rocks of this southern unit may have been Mountains, De Long Mountains, and Sheenjek) also have deposited in a rift basin on a south-facing passive continen- been defined as allochthons, and the rocks of the Venetie tal margin (Anderson and Wallace, 1991). This southern unit Subterrane have been described as an obducted thrust panel. crops out in a narrow belt along the Continental Divide, and The North Slope Subterrane is the northern parautochthonous probably extends westward into the northeast Arctic quad- subterrane onto which the allochthonous and obducted rangle (Anderson and others, 1993), where it is probably rep- subterranes have been thrust. Arranged in order from north resented by the unnamed units of Devonian and to south, the stratigraphic sequences of the subterranes dem- Mississippian(?) shale, sandstone, and conglomerate. onstrate that, in Devonian through Early Triassic times, dry land or generally shallow seas prevailed in the north, whereas Endicott Mountains Subterrane there appears to have been progressively deeper water to the south. The Endicott Mountains Subterrane of Jones and others The Hammond Subterrane, which extends along the (1987), later described in more detail by Silberling and oth- Brooks Range south of the Endicott Mountains and De Long ers (1992), consists of Devonian terrigenous clastic rocks, Mountains Subterranes, does not fit this pattern. It resembles Carboniferous shale and shelf carbonate deposits, and the North Slope Subterrane because it includes an extensive younger, mainly deep marine rocks. This stratigraphic as- basement of Lower Paleozoic and Proterozoic rocks that lo- semblage is referred to as the Endicott Mountains allochthon cally are overlain unconformably by Mississippian rocks. At by Mull (1985). This sequence of rocks is most readily iden- depth, the Hammond Subterrane may be continuous with tified by the presence of coarse-grained fluvial clastic rocks the parautochthonous rocks beneath the North Slope accord- of the Upper Devonian and Lower Mississippian(?) Kanayut ing to Mayfield and others (1988). However, it may be Conglomerate, which are unique to the subterrane, and which, allochthonous rather than parautochthonous according to together with the underlying Noatak Sandstone, Hunt Fork Oldow and others (1987) and Moore and others (1994a). The Shale, and Beaucoup Formation, form the lower part of the Hammond also differs from the North Slope Subterrane in subterrane. At the top of the column, a stratigraphic assem- that a large part of the Hammond Subterrane consists of blage of radiolarian chert and varicolored shale distinguishes Lower Paleozoic carbonate rocks, whereas the nearest out- the Permian and Triassic rocks of this subterrane from the crops of the North Slope Subterrane consist of Lower Paleo- coarse-grained Permian and Triassic rocks in the North Slope zoic volcanic rocks and graptolitic shales. The Lower subterrane to the north. But similar chert-shale assemblages

3 occur in other subterranes to the south. Beaucoup Formation in the Hammond Subterrane, because Our definition of the subterrane differs in one respect they showed the overlying Hunt Fork Shale as the lowest from that of Moore and others (1994a). They place the base unit of the Endicott Mountains Subterrane. We have mapped of the Endicott Mountains Subterrane at the base of the the north boundary of the Hammond Subterrane at a large Beaucoup Formation, but also suggest that the Beaucoup fault, along which the Hunt Fork Shale and the wacke mem- Formation may be in both the Endicott Mountains and the ber of the Beaucoup Formation are thrust onto the Lisburne Hammond Subterranes, or that different parts of the Beaucoup Group and the Kanayut Conglomerate of the Endicott Moun- may be in each subterrane. We place the older members of tains Subterrane, and south of which the Kanayut is repre- the Beaucoup in sedimentary sequence with the carbonate sented by partly marine quartzite rather than the typical rocks of the Hammond Subterrane, and we place the younger fluvial conglomerate. Thus, the stratigraphic location of the wacke member in both subterranes. subterrane boundary is unclear. The lower members of the We have mapped the Kanayut Conglomerate as extend- Beaucoup must be part of the Hammond Subterrane because ing farther north than other workers have; and consequently, the basal beds are limestone pebble conglomerate where they we have mapped the north edge of the Endicott Mountains rest on the Skajit Limestone. However, Moore and others Subterrane farther north. Most maps (for example, Moore (1994a) warned that these lower members of the Beaucoup and others, 1994a, b; Imm and others, 1993) show the north might be stratigraphically or structurally separated from the edge of the subterrane at the north edge of the big outcrops type Beaucoup because at the type locality they are found of Kanayut Conglomerate that extend from the east quad- adjacent to, but not in, the type section. So it is possible for rangle boundary east of the head of Old Woman Creek south- different members to be present in different subterranes. On westward through Tetsyeh and Nichenthraw Mountains. the other hand we show the wacke member, as well as the However, we also identify the Kanayut Conglomerate in a Hunt Fork Shale, to be present in both subterranes. long east-trending belt north of Cane and Sheep Creeks. Imm and others (1993) show those rocks as probably equivalent Sheenjek Subterrane to the Kekiktuk Conglomerate, but we assign them to the Kanayut because the lower part of the Kanayut in that area is Jones and others (1987) described the Sheenjek Terrane red shale and green wacke strikingly like that in the lower as composed of thin Mississippian limestone which is overlain part of the unquestioned Kanayut east of Old Woman Creek. by Upper Paleozoic and Triassic chert and varicolored argillite Similarly, where Imm and others (1993) show conglomerate and intruded by mafic sills. In the type area west of the Coleen probably equivalent to the Kekiktuk in a small anticline near River in the Coleen quadrangle, the terrane they outlined also Carter Pass, we have mapped Kanayut, because of Devo- includes a unit of black shale and chert and fine-grained sand- nian(?) fossils and typical Kanayut lithologies there. (See stone (Brosgé and Reiser, 1969). The terrane Jones and others Description of Map Units.) mapped is confined to a narrow belt that extends northwest- Because we place the boundary so far north, the Endicott ward about 60 mi from the Coleen River in the Coleen quad- Mountains Subterrane covers a very large area. If the North rangle to an outlying klippe in the Arctic quadrangle. Moore Slope Subterrane lies beneath these rocks, it is possible that and others (1994a) included these rocks in the much larger De folding and imbrication subsequent to their emplacement Long Mountains Subterrane which is present discontinuously has locally exposed North Slope Subterrane rocks among throughout the Brooks Range. This subterrane comprises four the Endicott Mountains Subterrane rocks. This might ex- of the allochthons of Mayfield and others (1988). The second plain the presence, in the northeast part of the Endicott highest, the Ipnavik River Allochthon, is a sequence of rocks Mountains Subterrane, of a distinctive unit of Middle and almost identical to that of the Sheenjek Subterrane, so applica- Upper Devonian shale, limestone, and conglomerate that is tion of the De Long Mountains Subterrane name is appropri- probably equivalent to rocks in the North Slope southern ate. However we retain the name Sheenjek, because it is a local unit of Anderson (1991b). name and in order to reserve the name De Long Mountains Subterrane for the klippen of the Picnic Creek Allochthon of Hammond Subterrane the De Long Mountains Subterrane which also occurs in the Arctic quadrangle. The Hammond Subterrane was defined as consisting of thick Lower Paleozoic carbonate rocks, Devonian granite, Venetie Subterrane and a variety of slightly metamorphosed Devonian and older sedimentary rocks (Jones and others, 1987). As mapped in Jones and others (1987) gave the name Venetie Terrane the Arctic quadrangle by Moore and others (1994a), it con- to Devonian(?) graywacke and Upper Paleozoic and Trias- sists mostly of the Skajit Limestone. They mapped the over- sic(?) chert that strike northeastward through the old Venetie lying Beaucoup Formation as part of the Endicott Mountains Indian Reservation in a wide belt along the east side of the Subterrane. On the other hand, Jones and others (1987) and East Fork Chandalar River. Similar rocks of similar age crop Nokleberg and others (1994) apparently placed the entire out in a long narrow belt along the south edge of the Brooks

4 Range that was called the Slate Creek thrust panel of the De Long Mountains Subterrane Angayucham-Tozitna Terrane by Patton and Box (1989). Moore and others (1994a) have combined the rocks of both Two small areas outlined near the heads of Smoke Creek of these belts into the Slate Creek Subterrane of the Arctic and Crow Nest Creek include a sequence of Mississippian Alaska Terrane. However, we retain the local name Venetie black shale, Mississippian black chert, and Carboniferous for the rocks in the Arctic quadrangle because they are sepa- to Permian varicolored chert typical of the upper part of the rated by 50 mi from the Slate Creek rocks, and whereas the Picnic Creek Allochthon of the De Long Mountains Slate Creek rocks rest consistently on the schists of the Subterrane (Mull and others, 1987; Mayfield and others, Coldfoot Subterrane, the Venetie rocks rest discordantly 1988). These rocks are shown as klippen, although the na- across the east ends of both the Ruby and the Hammond ture of their contacts with the surrounding Devonian rocks Subterranes. is uncertain. Where these rocks rest locally on Kanayut Con- glomerate, typical of the Endicott Mountains Subterrane, Venetie and Sheenjek Subterranes, undivided they probably are thrust on the Kanayut. At other places, A structural assemblage of parts of two subterranes they rest on the wacke member of the Beaucoup Formation, a unit that not only occurs in the Endicott Mountains A long synclinorium extends across the Arctic quad- Subterrane, but also is similar to the rocks in the base of the rangle from south of the Junjik River to Old Woman Creek. typical Picnic Creek Allochthon. The Mississippian shale The entire synclinorium is probably a large complex klippe. and chert and Carboniferous to Permian varicolored chert The rocks grouped together within it include rocks that are crop out just east of, and on strike with, small outcrops of definitely part of the Venetie Subterrane, rocks that are defi- Mississippian limestone and Permian varicolored shale and nitely part of the Sheenjek Subterrane, and rocks that may argillite that rest on the Hunt Fork Shale of the Endicott belong to either subterrane. At its center are large klippen of Mountains Subterrane in the adjacent Philip Smith Moun- Devonian(?) wacke of the Venetie Subterrane. Beneath these tains quadrangle (Brosgé and others, 1979). Those rocks klippen, on the limbs of the synclinorium, are Upper Paleo- might also be klippen. If so, the cherty rocks in the Arctic zoic and Triassic(?) chert and varicolored argillites like the quadrangle may grade westward into the limestone and argil- rocks that occur in both the Venetie and Sheenjek Subterranes. lite within a short distance. Thus, although the presence of Black cherty shale with interbedded sandstone like that in some rocks of the Picnic Creek Allochthon is certain, the the Sheenjek Subterrane occurs with these rocks on the south boundaries of the allochthon are not. limb near Old Woman Creek, and a small klippe of Missis- sippian limestone and gabbro sills typical of the Sheenjek Klippen of Endicott Mountains and De Long Mountains Subterrane lies above the Upper Paleozoic to Triassic(?) rocks Subterranes and Tozitna(?) Terrane near Mount Annette on the north limb. These rocks, not recognized by Jones and others (1987), Endicott Mountains and Venetie Subterranes, undivided are shown by Moore and others (1994a) as an outlier of the A structural assemblage of parts of two subterranes De Long Mountains Subterrane. The lowest allochthon of the De Long Mountains Subterrane in the western Brooks North of Nichenthraw Mountains an imbricated infold of Range is the Picnic Creek Allochthon (Mull and others, 1987; Upper Paleozoic rocks lies above the Carboniferous Lisburne and Moore and others, 1994a). Mississippian black chert and Group limestone of the Endicott Mountains Subterrane. The Pennsylvanian through Triassic gray and green chert char- rocks of the infold include Carboniferous (and younger?) vari- acteristic of the Picnic Creek Allochthon form most of Mount colored chert and slate like that of the Venetie Subterrane, and Annette near Porcupine Lake. These rocks are imbricated Mississippian limestone and Permian shale like those of the and form a little pile of klippen which rests on a broader area Endicott Mountains Subterrane. The north margin of this in- of Permian and Triassic chert and shale typical of the Endicott fold is marked by a large fault that juxtaposes two different Mountains Subterrane; these rocks in turn rest on the Per- Carboniferous facies where the Carboniferous chert and slate mian and Triassic shale, limestone, and sandstone typical of of the infold is thrust onto Permian shale and Carboniferous the surrounding North Slope Subterrane. Thus the whole area limestone of the Endicott Mountains Subterrane to the north. of cherty rocks is a klippe consisting of two allochthons The geology of the infold is poorly mapped, and probably is (Churkin and others, 1989). more complicated than shown. An isolated outcrop of Missis- Cretaceous rocks are also present. They rest on rock units sippian Kuna Formation represents a facies of the Lisburne of the subterranes and terrane within and outside the klippen, Group usually found in the Endicott Mountains Subterrane and may be unconformable on all of them. On Mount Annette, much farther west (Mull and others, 1982). Cretaceous(?) sand- they also occur below the klippen of the Picnic Creek stone in the infold is like that in the Endicott and De Long Allochthon and were therefore involved in the thrust fault- Mountains Subterranes in the north part of the quadrangle near ing. Although we placed the Cretaceous rocks in the strati- Mount Annette. The lateral extent of the infold is speculative. graphic column of the Endicott Mountains Subterrane, it is

5 likely that all of their outcrops are klippen. ammonites, and late Middle through Late Two small klippen of Triassic and Permian volcanic Triassic conodonts. Thickness more than rocks and chert rest on the Cretaceous rocks. The closest 300 ft, probably about 500 ft similar rocks are the Jurassic through Mississippian volca- ^Ps Sadlerochit Group, undivided (Lower Trias- nic rocks and chert of the Tozitna Terrane south of the Arc- sic and Permian)—Comprises Lower tic quadrangle. Triassic Ivishak Formation and Permian Echooka Formation. Ivishak Formation is black, silty shale, papery shale, and black, DESCRIPTION OF MAP UNITS shaley to splintery siltstone that weather brown to rusty. Shale and siltstone are locally UNCONSOLIDATED DEPOSITS micaceous and contain rare thin beds and lenses of dark-gray, fine-grained sandstone. Qu Surficial deposits, undivided (Holocene and Nodules and concretions of pyrite, clay Pleistocene)—Alluvial gravel, sand, and silt; ironstone, and phosphatic chert are locally glacial outwash of gravel and sand; and abundant. Calcareous concretions contain sandy bouldery gravel of glacial ground Lower Triassic (Scythian and Smithian) pele- moraine and terminal moraines in larger cypods and cephalopods. Thickness of valleys. Glacial deposits are from four glacial Ivishak not known, probably about 1,000 advances (Yeend and Brosgé, 1973a, b) that ft. The Echooka Formation is easily rec- are described by Coulter and others (1962) ognized almost everywhere at the base of as the Sagavanirktok River, Itkillik, Echooka the Sadlerochit Group by the yellow-orange- River, and Alapah Mountain glaciations. weathering color of the pyritic calcareous These are probably equivalent to the siltstone in the lower part of the formation. Sagavanirktok (Middle? Pleistocene) through The Echooka consists of gray to black late Itkillik (Late Pleistocene) advances siltstone with calcareous and ironstone recognized in the adjacent Philip Smith concretions and rare layers of hematite Mountains quadrangle (Hamilton, 1978; oolite; yellow-weathering, pyritic, calcar- Hamilton and Porter, 1975) eous siltstone and sandstone; beds of fine- grained, yellow, silty limestone; and lenses BEDROCK of reddish-weathering, gray, fine-grained limestone. Unusual basal beds exposed 3 North Slope Subterrane mi north of Porcupine Lake consist of 86 ft of fine-grained quartzite and pebble- Ki Ipewik unit (Lower Cretaceous, Valanginian)— granule conglomerate that contain chert and Black clay and silt shale, manganiferous; argillite clasts, overlain by gray, silvery- contains botryoidal nodules and concre- weathering silt shale (Peace, 1979; Barker, tions of phosphatic chert. Float and poorly 1981). No fossils have been collected from exposed thin layers or lenses of brown- the Echooka in this subterrane but the dis- weathering Valanginian pelecypod shell tinctive yellow calcareous rocks in the lower coquina (Buchia spp.) are found in the lower part of the formation are like those that con- part of this 100-ft thick unit. Mapped near tain Lower Permian brachiopods in the Mount Annette in northern part of quad- subterrane to the south (Detterman, 1988). rangle. Named informally by Crane and Measured thickness southwest of Porcupine Wiggins (1976) in western Brooks Range, Lake is 260 ft (Detterman, 1988) and recognized north of the central Brooks P&t Unnamed tuff (Permian or Pennsylvanian)— Range (Moore and others, 1994a) Light-green lapilli tuff in massive to lami- ^s Shublik Formation (Upper and Middle Tri- nated beds. Consists of angular clasts of assic)—Black, silty, partly calcareous, sooty pumice and cinders as large as 1.5 in. in shale, with local calcareous concretions and diameter, altered to chlorite and palagonite; interbedded black silty and shaley limestone. in carbonate and pyritic feldspathic matrix. Some gray to black, dense, fine-grained Tuff and underlying limestone contain pyrite limestone that weathers brown to cream and chalcopyrite. Fluorite boulders in float colored. Limestone beds contain phosphate (Peace, 1979; Barker, 1981). About 50 to nodules, late Middle and Late Triassic 75 ft thick. Mapped at only one locality in (Ladinian through Norian) pelecypods and northwest part of quadrangle. Overlain

6 directly by Sadlerochit Group slate. Rests weathering, white massive chert with veins on 10 ft of silicified Lisburne Group lime- of quartz and fluorite; at one locality the stone underlain by cherty limestone with top is green tuffaceous limestone with conodonts of latest Late Mississippian age. disseminated pyrite and fluorite replacing Probably either Pennsylvanian or earliest crinoids and bryozoans; a mineralized zone Permian as much as 8 ft thick lies about 80 ft below &Ml Lisburne Group (Pennsylvanian and Missis- the top (Peace, 1979; Barker, 1981). Base sippian)—Cliff-forming, gray limestone with of unit is poorly defined; it has been ex- light-gray to black nodular chert; minor amined only in the measured sections outside dolomite and silicified limestone. Top beds the quadrangle. Judging from these sections locally replaced by layer of rusty-weathering and from an incomplete section near Por- massive chert. Lisburne in this subterrane cupine Lake, the unit is about 2,000 ft thick contains early Late Mississippian to in this subterrane. Age of the base is prob- Middle(?) Pennsylvanian corals and brachio- ably late early Late to early late Late Mis- pods. Thickness is about 2,300 to 3,200 ft sissippian (late Meramecian to early based on incomplete measured sections. In Chesterian). Top ranges in age from lat- the adjacent Mount Michelson and est Late Mississippian to Middle(?) Penn- Sagavanirktok quadrangles, the Lisburne sylvanian (Late Chesterian to Atokan?) Group is divided formally into Wachsmuth(?) Mll Lisburne Group, lower unit (Upper Mississip- Limestone (early Late Mississippian), Alapah pian)—Mostly dark-gray, fine- to medium- Limestone (Late Mississippian) (Mamet and grained limestone and minor amount of Armstrong, 1972; and Armstrong and interbedded shaley limestone. Unit weathers Mamet, 1977), and Wahoo Limestone (Latest dark to medium gray and red and yellow. Mississippian to Early and Middle(?) Penn- Unit is about 50 percent dolomitized and sylvanian) (Watts, 1989). Judging from these contains black nodular chert. Base of unit measured sections and from incomplete contains corals of early Late Mississip- sections near Porcupine Lake, and near pian age (Meramecian). Top is probably Wahoo Lake 3 mi northwest of this quad- early or late Late Mississippian in age rangle (Brosgé and others 1952, 1962), (Meramecian or Chesterian). About 1,000 thicknesses of the formations in the northern to 1,200 ft thick judging from measured part of the Arctic quadrangle are: Wachsmuth sections north of Arctic quadrangle (Brosgé Limestone, from zero to 700 ft; Alapah and others, 1962; and Armstrong and Mamet, Limestone, from 1,000 to 1,500 ft; and 1977) Wahoo Limestone, from 800 to 1,000 ft. Mk Kayak Shale (Upper? Mississippian)—Black In reconnaissance mapping of the Arctic phyllitic shale with ironstone concretions; quadrangle we did not map the three for- contains interbedded thin beds of orange- to mal subdivisions of the Lisburne Group, brown-weathering crinoidal limestone. Lower instead we divided the Lisburne informally part contains about 100 ft of interbedded into a light-colored upper map unit (&Mlu) shale and dark-gray, very fine grained and a darker lower unit (Mll) that are rec- sandstone. Thickness about 500 ft. Contains ognized by their dominant weathering colors foraminifera of Late(?) Mississippian in the field and on aerial photographs and (Meremecian?) age. Identification is ques- are similar to the units mapped in the tioned in northeast corner of quadrangle adjacent Philip Smith Mountains quad- where the unit consists of black rusty shale rangle to the west (Brosgé and others, and brown to rusty, fine-grained, schistose, 1979). Where these units cannot be dis- partly calcareous sandstone and quartzite tinguished, we have mapped undivided with crinoid debris, gastropods, and pele- Lisburne Group (&Ml) cypods; some brachiopods, fish plates, and &Mlu Lisburne Group, upper unit (Middle? Penn- worm trails, all of indeterminate age sylvanian to Upper Mississippian)— Mkk Kayak Shale and Kekiktuk Conglomerate, Medium gray, fine- to medium-grained undivided (Mississippian)—Black shale, limestone and calcilutite and white nodu- black fine- to coarse-grained quartzite and lar chert. At some places near Porcupine coal. Mapped at one locality in northeast Lake, the top beds are 25 to 50 ft of rusty- corner of quadrangle

7 Mkt Kekiktuk Conglomerate (Lower Mississip- ten commun., 5/5/81). Mapped only at head pian)—Quartzite, conglomerate, sandstone, of East Fork Chandalar River and micaceous rusty shale; interbedded in MDsc Unnamed sheared conglomerate (Mississippian fluvial cycles. Contains minor coal and iron- or Devonian)—Sheared conglomerate com- stone. Conglomerate pebbles, 2 to 8 cm long, posed of chert and argillite pebbles as long consist mostly of quartz (50 to 80 percent) as 1 cm. Unit weathers brown and yellow and chert, with some pebbles of phyllite and and contains minor black shale and siltstone. limonitic sandstone. Quartzite is gray, fine Makes brown rubble slopes. Shale bed in to coarse grained, thin to massive bedded. similar conglomerate at head of Sheenjek Detrital grains are more than 80 percent River, 4 mi east of Arctic quadrangle quartz with minor chert; some secondary contains plant fossils of probable Devonian sericite, chlorite, and pyrophyllite. Ferrugi- age (Mamay, written commun., 5/5/81). May nous, fine-grained, carbonaceous sandstone be equivalent to upper, plant-bearing part is mostly chert grains. Thickness 125 to 300 of the Ulungarat Formation (informal name) ft on Canning River and East Fork Chandalar of Anderson (1991a, b) mapped 15 mi east River; may be as much as 1,000 ft thick of the Arctic quadrangle. If so, the thick- on upper Hulahula River. Contains plants ness may be about 600 ft. Mapped in of Early Mississippian age (Floral Zone 1, northeast corner of quadrangle Read and Mamay, 1964). Identification Dr Unnamed rhyolite (Devonian?)—Metamorphosed questioned at one locality where conglom- crystal and lithic tuff, volcanic breccia, and erate is quartz rich, but is sheared and brown minor porphyry of rhyolitic compositions, weathering and interbedded with brown now mostly recrystallized to fine crystal- schistose sandstone like sheared conglom- line quartz-sericite schist; gray, green, and erate unit MDsc purple; weathers yellow, rusty, and orange MDbs Unnamed brown sandstone (Mississippian or and white. Composed of quartz, sericite, Devonian)—Ferruginous, brown, partly albite, calcite, chlorite, and iron oxides; schistose sandstone and quartzite interbedded epidosite at one locality. Mostly a fine with gray, fine- to coarse-grained quartz- crystalline mosaic of quartz and mica with ite; pebbly quartzite and conglomerate; black some relic phenocrysts and clasts. Porphyry shale and ironstone. Conglomerate contains contains plagioclase phenocrysts in felsic pebbles of quartz, chert, and slate chips as ground mass. Thickness of unit ranges from long as 9 cm; partly sheared, partly brown 25 ft to hundreds or perhaps thousands of weathering. Makes brown rubble slopes. ft. Underlies Mississippian Kekiktuk Con- Thickness not known. Unfossiliferous, but glomerate. Apparently interbedded with apparently underlies Kayak Shale and Devonian(?) unnamed shale and sandstone Kekiktuk Conglomerate, so age is Missis- (Ds) and with Mississippian or Devonian sippian or older. Mapped near head of East unnamed brown sandstone unit (MDbs). Fork Chandalar River Mapped near upper East Fork Chandalar MDv Unnamed volcanic rocks (Mississippian or De- River vonian)—Green andesitic tuff and volca- |v Unnamed volcanic rocks (Devonian? or older)— nic breccia weathers yellow and orange; Metamorphosed dacitic to andesitic layered sheared, schistose and altered to chlorite, crystal and lithic tuff, volcanic breccia, epidote, clinopyroxene, and clay. Thickness vesicular flows and minor intrusive rocks; probably a few hundred feet. Stratigraphic green, purple, orange, and red; distinguished relations uncertain. May be interbedded with by dark-purple and green weathering col- sheared conglomerate unit (MDsc) or with ors. Fine-grained tuffs are now phyllite. Kekiktuk Conglomerate (Mkt). Basaltic Coarser grained rocks are lower greenschist volcaniclastic rocks 4 mi to east in Table facies assemblages of quartz, albite, sericite, Mountain quadrangle are interbedded with chlorite, epidote, stilpnomelane, calcite, Mississippian Kekiktuk Conglomerate, magnetite, and hematite. Includes some black according to Anderson and others (1993), shale and chert pebble conglomerate. but a shale and conglomerate layer within Underlies Mississippian Kekiktuk Conglom- those volcaniclastic rocks contains Devo- erate; may underlie Devonian(?) rhyolite nian(?) plants according to Mamay (writ- (Dr). Interlayered with Devonian(?) unnamed

8 shale and sandstone (Ds) at one locality, stone, is about 200 to 300 ft thick, and so probably Devonian, in part. Mapped in contains Upper Triassic (Norian) pelecy- northeast part of quadrangle pods (Monotis). Lower part is dominantly Ds Unnamed shale and sandstone (Devonian?)— shaley, is about 450 to 600 ft thick, and con- Mostly black shale, in part rusty weath- tains Upper and Middle Triassic (Karnian ering; interbeds of dark-gray, fine- to and Ladinian) pelecypods (Halobia and coarse-grained quartzite and dark-gray, Daonella) brown-weathering, fine-grained sandstone. ^s Shublik Formation (Triassic)—Limestone and Contains pelecypods of Devonian(?) age shale. Limestone is black, silty, sooty; and and unidentifiable plant fragments. Prob- gray to black, thin bedded, yellow weath- ably less than 1,000 ft thick. Mapped lo- ering. Shale is black, silty, partly cally west of upper East Fork Chandalar manganiferous, and weathers gray and River brown. Few thin beds of hard black quartz O_c Unnamed chert and phyllite (Ordovician and siltstone at one locality. No fossils found; Cambrian?)—Structural assemblage of probably same age as Otuk Formation. lenses of bedded chert in structurally More than 250 ft thick. Exposed at only complex matrix of pale-green, yellow- two places in this subterrane, near Up- weathering slate and argillite and dark- per Sheep Creek and near Little Njoo gray, black, and red phyllite. Chert is Mountain north of Junjik River black to gray, or white, rusty weathering; ^Pss Sadlerochit Group and Siksikpuk Formation?, radiolarian; foliated and recrystallized. Also undifferentiated (Lower Triassic and Per- contains minor orange-weathering breccia mian)—Upper part of the Sadlerochit Group or conglomerate of very fine grained do- (Ivishak Formation) is mostly black to dark lomite (Moore and Churkin, 1984). Thick- olive-gray clay shale, silty shale, and silt- ness probably greater than 1,000 ft (Anderson stone. This part is pyritic, manganiferous, 1991a). Contains probable Middle Ordovi- and weathers rusty and contains calcareous cian graptolites. Part of unit contains lenses concretions, ironstone concretions and phos- of Cambrian volcanic rocks (_v). Same as phatic chert nodules. It also contains mi- Romanzof Chert of Anderson (1991a). nor black, fine-grained to very fine grained Mapped at north edge of quadrangle quartzite; a few 5- to 20-ft-thick beds of _v Unnamed volcanic rocks (Cambrian)—Mafic black chert; rare dolomite lenses. Lower part volcanic breccia, basalt, and vesicular (Echooka Formation) consists of gray to amygdaloidal flows; green, weathers light black, pyritic, micaceous, partly rusty- red. Contains interbedded chert and green weathering clay shale, silty shale and silt- laminated argillite. North of Arctic quad- stone; some black, very fine grained rangle, includes fossiliferous limestone sandstone, minor hematitic sandstone, and (Reiser and others, 1971) that contains Lower oolites of hematite. Calcareous and phos- Cambrian trilobites. Thickness probably phatic concretions, ironstone and phosphatic several hundred feet chert nodules are abundant. At base of Echooka Formation is a characteristic Endicott Mountains Subterrane yellow-weathering zone of calcareous and non-calcareous pyritic shale, siltstone, and ^o Otuk Formation (Upper and Middle Triassic)— very fine grained sandstone, with interbedded Limestone and shale. Upper part is medium- to dark-gray limestone. Measured interbedded, gray, fine-grained, dense, platy sections indicate that the Ivishak Forma- limestone that weathers smooth and yellow, tion is about 1,000 to 1,500 ft thick and the and gray and black, medium-grained, thin- Echooka Formation is 400 to 1,450 ft thick bedded limestone that weathers yellow and (Detterman, 1988). No fossils found in black; with interbedded manganiferous silty Ivishak. Echooka Formation contains bra- shale that weathers gray and brown. Lower chiopods of Early Permian (Wordian) age. part is interbedded black shale, black, sooty At many places in the south half of this phosphatic limestone, and gray, fine-grained subterrane, rocks of the Sadlerochit Group limestone that weathers smooth and cream- described above, are interbedded with colored. Upper part is dominantly lime- additional intervals 500 to 1,300 ft thick

9 that were assigned to the Siksikpuk For- near faults. Lisburne in the northern part mation(?) by Detterman (1988). Rocks in of this subterrane is about 2,500 ft thick, these intervals are mostly black shale and in the southern part about 1,500 ft thick, siltstone, but include 50 to 100 ft of black and about 500 ft thick in southernmost to gray-green, bedded, silty, radiolarian exposures (separately mapped as Ml). The chert that is partly phosphatic. They youngest beds are Early and Middle Penn- contain radiolarians of Late Paleozoic age sylvanian in age (locally latest Mississip- and rest on the yellow-weathering calcar- pian) north of the Junjik River based on eous rocks of the Echooka Formation that brachiopods and conodonts. The oldest beds contain Permian brachiopods. Where the are early Late Mississippian in the north Siksikpuk(?) Formation is present the total based on foraminifera; whereas they are undifferentiated unit is 1,400 to more than Early Mississippian in the south based on 3,000 ft thick conodonts and brachiopods. In an incom- Pe Echooka Formation (Permian)—Gray, brown, plete measured section at the Sheenjek River and black shale and slate, in part pyritic; 7 mi east of the Arctic quadrangle (Brosgé brown and greenish-gray shale. Identified and others, 1962), the Lisburne is divided by yellow-weathering gray to gray-green, formally into about 700 ft of Wachsmuth calcareous, pyritic shale and siltstone at Limestone (Early and early Late Mississip- base. Hematitic sandy oolite and a few pian) and about 1,300 ft of Alapah Lime- beds of ferruginous crinoidal limestone stone (Late Mississippian). These formations are interbedded with the black shale. are present throughout the subterrane. The Nodules of pyrite, barite, and ironstone overlying Wahoo Limestone (Pennsylvanian are present. About 200 to 600 ft thick. and Late Mississippian) is present in most Contains Permian brachiopods of the subterrane north of the Junjik River, Ps Siksikpuk Formation (Permian)—North of the but they could not be differentiated at the Junjik River consists of brown, olive, and reconnaissance scale of mapping. In some black shale and silty shale that weathers areas, the Lisburne is divided into infor- orange, olive, and silvery; green argillite mal subdivisions that consist of an upper with minor pyrite and some black, bedded light-gray weathering limestone unit (&Mlu) chert. Unit is identified as unquestioned and a lower darker-gray weathering unit (Mll) Siksikpuk Formation because of the green like those mapped in the Philip Smith Moun- argillite; red and green sediments are typical tains quadrangle to the west (Brosgé and of the Siksikpuk Formation (Adams and others, 1979). Where neither subdivision Siok, 1989). Rests on Middle(?) Pennsyl- is recognizable the entire Lisburne is mapped vanian limestone at top of Lisburne Group. as &Ml. In southernmost outcrops, where South of Junjik River and near Spoonfish limestone is thin and entirely Mississippian Lake includes much green and red pyritic in age, the unit is mapped as Ml shale and argillite and orange-weathering &Mlu Lisburne Group, upper part (Pennsylvanian siliceous siltstone with barite nodules; rests and Upper Mississippian)—Medium-gray, on Lower Mississippian limestone of fine- to medium-grained cherty limestone Lisburne Group. About 200 ft thick. No and silicified limestone; dolomite is rare. fossils found Capped locally by black chert layer described &Ml Lisburne Group (Middle Pennsylvanian to under unit &c. Fluorite replaces small calcite Lower Mississippian)—Gray limestone, vein in recrystallized packstone at one commonly silicified; very little dolomite; locality on Continental Divide at head of nodular black and gray chert is present Junjik River. Forms medium- to light-gray throughout. Chert is most abundant east of slopes as seen from distance or on aerial East Fork Chandalar River where chert layers photographs. Unit is probably about 1,000 locally ramify across bedding in lower part to 1,200 ft thick near center of quadrangle; of section. Beds at top of Lisburne com- it probably pinches out to south near Junjik monly replaced by 25 ft or more of brec- River. Top of unit contains late Late Mis- ciated chert, which is black north of Junjik sissippian foraminifera and Early to River (unit &c, mapped locally) and is white Middle(?) Pennsylvanian conodonts and to the south. Limestone partly recrystallized brachiopods. Base of unit is poorly defined

10 but includes beds of early late Late Mis- Mk Kayak Shale (Upper and Lower Mississip- sissippian (early Chesterian) to late early pian)—Black shale and slate with Late Mississippian (late Meramecian) age interbedded limestone and sandstone, com- &c Unnamed chert (Pennsylvanian)—Discontinuous monly contains ironstone concretions and, black, massive to brecciated chert, locally locally, phosphatic concretions and phos- with remnant lumps of partially replaced phatic pebbles. Weathers black to rusty. limestone; hematitic where underlying lime- Upper part of formation contains coarse- stone is hematitic. Thickness is from 1 or grained crinoidal limestone, generally in 2 ft to more than 100 ft, but generally is beds 5 to 10 ft thick, that weathers yel- 10 to 25 ft. Present north of Junjik River low or red and is locally hematitic. Lower in many places where not mapped. Underlies part contains sandstone as much as 150 fossiliferous Permian rocks of Sadlerochit ft thick. Sandstone is gray, fine to very Group. Disconformably overlies Lisburne fine grained, thin bedded to nodular, Group in areas where Lisburne is as young locally micaceous, and contains plant as Pennsylvanian. Unit may have been fragments and worm trails. Sandstone is formed by replacement and solution of lacking in southernmost outcrops near Lisburne during the Late Pennsylvanian. Spoonfish Lake and upper Smoke Creek. Small chip of fluorite at locality 4 mi Formation is about 500 to 1,000 ft thick. southeast of Carter Pass is probably related Commonly contains corals, brachiopods, to fluorite mineralization at this horizon near conodonts, and foraminifera of Early Porcupine Lake Mississippian (Osagian and Kinder- Ml Lisburne Group, undivided (Mississippian)— hookian? age), but contains corals and Gray, coarse-grained, crinoidal bioclastic brachiopods of early Late Mississippian limestone and medium-gray, fine-grained, (Meramecian) age in the northeastern part silty limestone. Includes minor amount of of the quadrangle medium-gray, medium-crystalline dolomite. Ms Unnamed siltstone (Mississippian)—Glassy to In upper part of unit, limestone is replaced laminated black chert that grades into by bands of partly silicified limestone and black, gray-weathering, sooty porous white chert. Black and white nodular chert siltstone; interbedded calcareous siltstone, present throughout. About 200 ft thick near minor black thin-bedded limestone, and Spoonfish Lake, possibly as much as 500 lenses of crinoidal limestone. Thickness ft thick farther west. Contains brachiopods uncertain. Similar rocks in quadrangles and corals of Early Mississippian age near to the east contain brachiopods of early(?) Spoonfish Lake and also near Smoke Creek Late Mississippian age (Brosgé and others, about 4 mi west of Arctic quadrangle (Brosgé 1976) and bryozoans of Permian or Car- and others, 1979). No evidence of Penn- boniferous age (Brosgé and Reiser, 1969). sylvanian limestone in those areas. Mapped Occupies stratigraphic position of Kayak in small areas near Spoonfish Lake and upper Shale. Mapped at one locality near head Smoke Creek of Koness River Mll Lisburne Group, lower part (Upper and Lower MDk Kanayut Conglomerate (Lower Mississippian? Mississippian)—Dark-gray, fine- to medium- and Upper Devonian)—Interbedded flu- grained limestone and silicified limestone with vial conglomerate, sandstone and shale in abundant black chert nodules or layers. Lower fining-upward cycles that are generally 10 part contains interbedded shaley limestone to 25 ft thick, and sandstone and conglom- and some yellow-weathering coarse-grained erate in couplets 10 to 30 ft thick. Conglom- limestone. Thickness about 1,000 to 1,500 erate is composed mostly of chert pebbles; ft, possibly decreasing to about 500 ft near more than 80 percent of the clasts are chert Junjik River. Basal part contains early Late at 15 of 18 localities where point counts Mississippian (early Meramecian) foramin- were made (Nilsen and others, 1980a, 1981). ifera in the north, probable Early Missis- The rest of the clasts are mostly vein quartz sippian (Osagian) conodonts in south. Top and quartzite. In thin sections, sandstone is poorly defined but youngest beds are is composed mostly of quartz, generally less probably late Late to early Late Mississippian than 20 percent chert and minor lithic (Chesterian to Meramecian) fragments, and mica, chlorite and pyrophyl- lite. Mean maximum pebble sizes at nine

11 localities range from 1 to 10 cm. Plant pebbles, and plants from near the base of fragments are common but, in the areas the upper part are probably Devonian (table mapped as Kanayut (MDk), they have been 1; no. 3). identified at only one locality, where they The only other definitely identifiable fos- are probably Devonian. sils collected from the Kanayut in the Arctic The formation in this area is about 2,500 quadrangle are Devonian plants from the ft thick and consists of three parts, an upper lower part of the formation. The Missis- part with about 20 percent shale, a middle sippian(?) age of part of the formation is part with less shale, and a lower part with by correlation with part of the Stuver 25 to 65 percent shale. These correspond Member near the Anaktuvuk River, 110 mi to the Stuver member, middle conglom- west of the Arctic quadrangle where plants erate member, and lower shale member of probable Mississippian age were found mapped in the adjacent Philip Smith (Nilsen and others, 1980a) Mountains quadrangle (Brosgé and oth- MDku Kanayut Conglomerate, undivided (Mississip- ers, 1979; described by Nilsen and oth- pian? and Devonian)—Mostly quartzite and ers, 1980a, 1981). They correspond sandstone with only minor amounts of con- approximately to the Stuver, Shainin Lake, glomerate and shale, so that more resistant and Ear Peak members formally named and less resistant members are not recog- in the type section farther west by Bowsher nized. Mostly fluvial near Index Mountain; and Dutro (1957) and Nilsen and Moore elsewhere fluvial and marine. Conglomerate (1984). However, they differ from the is rare except near Index Mountain, where formal members in that the middle part, it occurs at the base of fining-upward and as mapped, is not restricted to the mas- thinning-upward cycles that are about 25 sive amalgamated conglomerate and sand- ft thick. Pebbles of quartz and quartzite are stone beds defined as Shainin Lake more abundant than chert pebbles in most Member, but includes a thicker interval places, and are as much as 10 cm in diameter composed mostly, but not entirely, of near Index Mountain, 5 cm near Titus Moun- resistant beds. For this distinction, see tain, and 3 cm in the western part of the Nilsen and Moore (1984, p. A15ÐA16). subterrane. Quartzite occurs in the fining- All three parts are mapped separately only upward cycles, but is mostly in intervals near Nichenthraw Mountain. Elsewhere, of quartzite or sandstone hundreds of feet if all the parts are present, either the whole thick. Gray, fine- to coarse-grained, hard formation is mapped as MDk, or, locally, and blocky quartzite is composed of quartz the distinctively shaley lower part (Dkl) and chert grains, some lithic fragments, feld- and the combined middle and upper parts spar, and secondary limonite and sericite. (Dksm) are distinguished. In the southeast Gray quartzite near Titus Mountain contains part of the quadrangle the Kanayut is partly interbeds of brown, fine-grained, thick- marine and has no distinctive members, bedded manganiferous quartzite that con- and is therefore mapped separately as un- tains brachiopods. Sandstone is gray to divided Kanayut (MDku). At the outcrop brown, thin bedded, fine to coarse grained, near Carter Pass, the identification of the locally calcareous, and near Titus Moun- Kanayut is uncertain. The section measured tain contains corals and brachiopods. Minor there was described originally as Kanayut amounts of black and red shale or gray-green Conglomerate (Nilsen and others, 1980a), hematitic mudstone occur at the tops of then reassigned to the Kekiktuk Conglom- cycles. The unit is probably at least 1,000 erate (Nilsen and others, 1981), and sub- ft thick. It contains Late Devonian plants sequently mapped by Imm and others in black slate interbedded with the conglom- (1993) as an unnamed unit probably erate at Index Mountain, Late Devonian correlative with the Kekiktuk Conglom- (Famennian? and Frasnian?) brachiopods erate. We retain the original designation and corals in quartzite and sandstone near because the measured section contains Titus Mountain, and Late Devonian rocks similar to the two upper members (Famennian?) brachiopods in a thin bed of of the typical Kanayut, the conglomerate limestone interbedded in conglomerate near (like the typical Kanayut) is mostly of chert the west edge of the quadrangle

12 MDks Kanayut Conglomerate, Stuver Member (Lower overlying middle part of Kanayut, which Mississippian? and Upper Devonian)— also contains green shale rip-up clasts. No Quartzite, sandstone, conglomerate and shale, fossils found. In the area southwest of Old organized into fining-upward and thinning- Woman Creek, entirely red shale at upward cycles 20 to 50 ft thick. Conglom- Broshman Mountain; elsewhere consists of erate is minor, mostly of black chert pebbles, cycles 10 to 20 m thick that are about half but locally quartz rich. Pebbles as large as red and black shale and half rusty, fine- 5 cm diameter. Sandstone and quartzite are grained quartzite and conglomerate. There gray to maroon and rusty, tabular to cross the conglomerate pebbles are less than 5 bedded, partly micaceous, and contain iron- cm in diameter, and more than 90 percent stone nodules and black shale rip-up clasts. are chert, mainly gray and black. Shale Silt shale is black, red and yellow; contains contains Devonian plants. Deposited by fossil leaf and wood fragments. Fossil logs meandering streams (Nilsen and others, as much as 3 ft long occur in quartzite at 1980a). Thickness probably about 1000 ft one locality near Nichenthraw Mountain. Dr Unnamed rhyolite (Devonian?)—Metarhyolite. About 600 ft thick. This part of the Kanayut Yellow-weathering, crystal and lithic tuff contains Devonian(?) plants in the outcrops composed mostly of secondary quartz, near Carter Pass mapped as part of undi- sericite, and calcite; associated with schistose vided Kanayut(?). Deposited by meander- greenstone with malachite stain. About 50 ing streams (Nilsen and others, 1980a) ft thick. Only a few small outcrops, all of MDksm Kanayut Conglomerate, Stuver Member and them in, or directly under, the Kanayut middle part, undivided (Lower Missis- Conglomerate sippian? and Upper Devonian)—Consists Dn Noatak Sandstone (Upper Devonian)—Formerly of the more resistant upper parts of the described as the marine basal sandstone Kanayut as distinguished from the shaley member of the Kanayut Conglomerate lower part (Dkl). Where mapped, contains (Nilsen and others, 1981; Nilsen and Moore, unidentified plant fossils 1984). Interbedded orange-weathering, dark- Dkm Kanayut Conglomerate, middle part (Upper gray, fine-grained to very fine grained, thin- Devonian)—Cliff-forming unit of con- bedded, partly calcareous wacke and black glomerate and sandstone in massive, amal- siltstone and shale. Includes lenses of brown gamated beds 10 to 30 ft thick, and also calcareous sandstone that contain phosphatic in fining-upward cycles with shale at top. pebbles and lenses of sandy limestone Clasts in conglomerate are mostly black, coquina. Unidentified plant fossils are present gray, and white chert and as much as 11 in the shale. The coquina contains brachio- cm in diameter. Thickness is about 800 pods and conodonts of Late Devonian ft. No fossils found. Age is based on the (Famennian?) age. Thickness uncertain, Devonian(?) plants in the upper part and probably about 500 ft. Mostly deposited as Devonian plants in the lower part of the channel-mouth and offshore bars (Nilsen Kanayut. Deposited by braided streams and others, 1981). Present only in south- (Nilsen and others, 1980a) western part and near Tetsiyeh Mountain Dkl Kanayut Conglomerate, lower part (Upper De- in eastern part of quadrangle vonian)—Shale, slate, quartz-rich sandstone, Dhf Hunt Fork Shale, shale member (Upper De- wacke, and conglomerate. In the area north vonian)—Black to gray clay shale that of Old Woman Creek and Cane Creek, weathers brown to gray, brown-weathering consists mostly of micaceous red slate, shale micaceous silt shale, and gray-green, yellow- and argillite and green grit, hematitic sand- weathering slate that is partly pyritic or stone, and lithic wacke. Wacke is pyritic, manganiferous. Sandstone forms about 10 composed of angular grains of chert and to 25 percent of the unit and is mostly gray, quartz, rock fragments, and plagioclase in fine to medium grained, thin bedded to a matrix of calcite, sericite, chlorite, and shaley, ferruginous and locally hematitic, glauconite. Few beds of gray fine- to and partly calcareous. Some sandstone is medium-grained quartzite. Rare pebbles as gritty, coarse grained, medium bedded, and long as 1 cm. Red shale at top of unit is contains pebbles of quartz and shale. Green, interbedded with conglomerate at base of fine-grained graywacke is rare. Brachiopods

13 and crinoids occur in the sandstone and in Although originally described as Early and rare lumps of hematitic coquina and thin (or) Middle Devonian (Brosgé and others, beds of orange-weathering limestone. 1981), unit is now considered to be Middle Contains brachiopods, corals, and gastro- and Late Devonian. Similar in age and pods of early Late Devonian (Frasnian) age lithology to Ulungarat Formation of Ander- and conodonts of Middle to Late Devonian son (1991b) in Table Mountain and Demar- age. About 1,000 to 1,500 ft thick cation Point quadrangles to the east and Dbw Beaucoup Formation, wacke member (Upper northeast Devonian)—Dark-gray, very fine grained Dsc Unnamed sheared conglomerate (Devonian?)— to fine-grained limonitic wacke. Forms thin Sheared conglomerate of chert and slate irregular beds interbedded with black to olive pebbles as much as 10 cm in diameter; partly siltstone and shale. Shale is manganiferous calcareous, partly ferruginous; black mica- and partly micaceous and locally contains ceous shale and siltstone, and brown, fine- to phosphatic nodules. Also includes few beds medium-grained, orange-weathering, schistose of brown calcareous shale and brown- wacke and quartzite. Makes brown and black weathering calcareous siltstone that grades rubble slopes. Thickness probably several to limestone and to sandy limestone coquina; hundred feet. Probably equivalent in age rare beds of black gritty quartzite with chert to, or slightly older than, the rhyolite (Dr). pebbles 1 to 3 cm in diameter. Sandstone Contains more black shale than the unnamed is composed of detrital grains of quartz, chert, sheared conglomerate unit (MDsc) of North lithic fragments, and some plagioclase, Slope Subterrane; less shale than the un- cemented by chlorite and calcite. Foliated named shale and sandstone unit (Ds) of that chloritic quartz siltstone grades to clear subterrane quartzite. Unidentified plant fragments are Dhl Hunt Fork Shale, limestone member (Upper present in shale. Calcareous rocks contain Devonian)—Dark-gray, gray-weathering, fine- atrypid, cyrtospiriferid, and productellid grained limestone and orange-weathering, brachiopods, corals, and gastropods, all of argillaceous, shaley to nodular limestone. early Late Devonian (Frasnian) age and Contains atrypid brachiopods and corals of conodonts of Late Devonian age. Thickness early Late Devonian (Frasnian) age. About is uncertain, possibly about 1,000 ft 50 to 100 ft thick. Near the middle of the Dls Unnamed limestone, shale, and conglomer- shale member of the Hunt Fork Shale ate (Upper and Middle Devonian)— Dbl Beaucoup Formation, limestone member (Upper Interbedded limestone, calcareous siltstone, or Middle Devonian)—Light-gray, coarse- shale, and quartzite in layers 25 to 100 ft grained, crinoidal limestone and medium- thick. Limestone is black to dark gray, mostly gray, fine- to medium-grained, saccharoidal fine grained and orange weathering. limestone; contains irregular bands and Crinoidal calcareous siltstone consists of replacement patches of medium-gray to micaceous, orange-weathering subgraywacke black chert. Present at only one locality composed of detrital grains of quartz, calcite, on the East Fork Chandalar River. About plagioclase, chlorite, muscovite, and sphene. 200 to 300 ft thick. Contains conodonts of Shale is black, silty, partly micaceous. Middle or early Late Devonian age. In other Quartzite is black, coarse, pebbly chert respects, resembles limestone of Lisburne arenite that contains chert pebbles as much Group as 2 cm in diameter. Calcareous siltstone Dm Unnamed mafic rocks (Devonian?)—Two or is hornfelsed at contacts with small diabase more 25-ft-thick sills of light-green, rusty- sills of unit Dm. Unit commonly weathers weathering, fine- to medium-crystalline to yellow slopes. Thickness of unit is metadiabase. Diabasic texture is preserved uncertain, probably 500 to 1,000 ft. Lime- although igneous minerals have been altered stone contains brachiopods, bryozoans, to chlorite and magnetite, albite, and clay tentaculitids, and a trilobite, all of Middle with accessory sphene; patches of calcite Devonian age and, at one locality near top may represent vesicle fillings. Fossilifer- of unit, corals of Late(?) Devonian age. ous (Middle? Devonian) calcareous siltstone Calcareous siltstone contains brachiopods of unit Dls has hornfels zones at contacts and pelecypods of Middle(?) Devonian age. with sills

14 Hammond Subterrane slate of the Hunt Fork Shale (Dhf). Some flows are vesicular, others are composed Dkq Kanayut Conglomerate, quartzite member (Up- of pillows cemented by tuff and greenstone. per Devonian)—Quartzite, sandstone, and Conglomerate between volcanic flows is shale that form fining- and thinning-upward composed of lumps of mafic rock and cycles about 25 to 50 ft thick. Quartzite is pebbles of limestone in a matrix of slate gray, fine to coarse grained, and partly rusty that may have been debris-flow mud. The weathering. It is massive at base of cycles volcanic rocks are now greenstone. Phenoc- and thin bedded and crossbedded above. rysts of hornblende are altered to chlorite; Sandstone near tops of cycles is thin and albite/andesine to sericite; plagioclase to shaley. Shale is black and brown. Plant feldspar and calcite; pyroxene to chlorite fragments, and mixed plant, brachiopod, and and magnetite. The volcanic matrix has been crinoid fragments occur in the shale at the altered to epidote, chlorite, quartz, albite, top of some cycles. About 500 to 1,000 ft and actinolite. Limestone clasts in the thick. Contains brachiopods of Late Devo- volcanic breccias and the conglomerate nian (Famennian) age. Lack of conglom- contain brachiopods and conodonts of Late erate distinguishes this member from other Devonian (Frasnian) age. Thickness varies members of the Kanayut from about 500 ft to less than 100 ft. Unit Dn Noatak Sandstone (Upper Devonian)—Sand- is present locally between Old John Lake stone and shale. East of Koness River unit and Koness River is mostly yellow to gray-green, orange to Dv Unnamed volcanic rocks (Devonian)—Metamor- gray weathering, thin bedded to shaley, phosed sills and dikes of dacite, latite, or bioturbated sandstone. Also includes andesite and flows of rhyolite that intrude brown- and gray-weathering, medium- to the conglomerate and shale member of coarse-grained, thin-bedded calcareous Beaucoup Formation and intrude and overlie sandstone and dark-red, fine-grained, the Skajit Limestone. Intrusive rocks are bioturbated hematitic sandstone. Intervals fine to coarse crystalline, porphyritic, and of black, worm-burrowed siltstone and gray- composed of plagioclase and potassium green, mottled, irregularly bedded, worm- feldspars altered to sericite and phenocrysts burrowed mudstone; minor amounts of black of volcanic quartz. Brown hornblende in part and brown, partly calcareous shale. West is altered to actinolite; biotite is rare. Matrix of Koness River some sandstone is black, is composed of sericite, chlorite, and cal- yellow weathering, fine grained, shaley, and cite. Skajit Limestone is green and silici- bioturbated; some is light gray, very fine fied at the intrusive contacts. Flows that grained, rusty, thin bedded, with load casts rest on the Skajit Limestone are porphy- and ironstone concretions; and some is gray- ritic, composed of plagioclase, quartz, and green, fine- to medium-grained, limonitic, sericite, with feldspar phenocrysts altered thin- to medium-bedded quartz wacke. The to chlorite, calcite, and epidote. Secondary wacke is composed of quartz and chert grains pumpellyite and stilpnomelane are rare. in a matrix of clay, sericite, chlorite, and Thickness of individual flows or sills carbonate with minor sphene and pyrophyl- varies; the thickest of each is about 1,000 lite. Indeterminate plant fragments were ft. Also included in the unit are a few small found in the quartz wacke, and cyrtospiriferid dikes of metamorphosed basalt that intrude brachiopods of Late Devonian (Famennian) the Hunt Fork Shale and are associated with age occur in the associated sandstone. tuff unit Dvt. A Devonian age for the unit Cyrtospiriferid brachiopods also are present is based on the Devonian age of the fos- in the sandstone east of the Koness River. sils in the associated unit Dvt and on the Thickness is more than 300 ft, possibly as apparent relation of the volcanic rocks with much as 1,000 ft. Identified only east of rocks of the Upper Devonian Beaucoup East Fork Chandalar River Formation, which contain clasts and intrusive Dvt Unnamed volcanic rocks and tuff (Upper De- bodies of volcanic rocks vonian)—Metamorphosed basaltic and Dhf Hunt Fork Shale, shale member (Upper De- andesitic flows and andesitic tuffs, crystal vonian)—Dark-gray to black shale and slate tuff, breccia, and volcanic conglomerate al- that weathers gray and brown; and dark- tered to greenstone, interbedded in black gray, brown-weathering, irregularly bedded

15 siltstone. Includes minor gray, fine- to argillite. Some clasts are quartz and quartzite, medium-grained, cross-bedded quartzite, and and rare pebbles ironstone. The conglom- gray, very fine grained, thin-bedded quartz erate matrix is ferruginous grit to siltstone. sandstone composed of quartz, chert, and Near Misty Mountain are beds of unusual lithic fragments with minor sericite. Locally maroon conglomerate that contains red chert contains some thin beds of calcareous and slate pebbles. Quartz wacke and arenite crinoidal sandstone and shaley bioturbated make up 20 to 40 percent of the member. sandstone. Near top of unit in southeast- They are schistose, micaceous, yellow and ern part of quadrangle, contains interbeds brown, fine to medium grained and con- of tuff and fossiliferous volcanic conglom- sist mostly of quartz, chert and plagioclase erate (Dvt) that contain Late Devonian grains, some lithic fragments, and some (Frasnian) fossils. Thickness uncertain, fragments of volcanic rock near the outcrops possibly 1,000 to 1,500 ft of volcanic rocks (Dv) in the southwestern Dbw Beaucoup Formation, wacke member (Upper part of the quadrangle. Matrix is sericite, Devonian)—Interbedded schistose lithic chlorite, calcite, and iron oxides. Sericite wacke, quartz sandstone, siltstone, and shale. lies both in the foliation and within the clasts. Each of these rock types also forms dis- Black and gray shale, slate, phyllite, and crete units several hundred feet thick. Wacke siliceous siltstone, and purple and green is dark gray and gray-green, fine to medium shale, slate, and chloritic siltstone make up grained, shaley to medium bedded, mica- 20 to 30 percent of the member. They ceous, ferruginous, manganiferous, partly produce the overall purplish weathering color calcareous, and weathers green and orange. that characterizes the member. Locally, the It contains load casts and plant fragments. contact of this member with the overlying Wacke is composed of chert, quartz, mica, wacke member (Dbw) is gradational. Where and slate chips. Sandstone is brown and dark the member rests on Skajit Limestone, the gray, very fine grained to fine grained, thin basal beds are limestone cobble conglom- bedded, micaceous, partly calcareous. erate with clasts as much as 18 cm in Quartzite is brown and gray, white weath- diameter. Where it rests on the siltstone ering, fine to medium grained, thin bedded, member of the Beaucoup Formation (Dbs) and contains ironstone nodules. A minor a basal limestone bed contains pebbles of amount of green quartz grit and granule- slate. At one locality northeast of Crow Nest pebble conglomerate is composed of quartz, Creek, a thin bed of black, fine-grained chert, and slate chip clasts, and grades to limestone occurs within the conglomerate wacke. Micaceous shaley siltstone and shale near the top of the member. Thin layers of is dark gray, black, and gray-green, and calcareous sandstone within the sheared contains clay pebbles, bottom marks, worm conglomerate and limestone lenses in cal- burrows, and brachiopods. Lenses of cal- careous grit contain crinoids and snails of careous chert-pebble conglomerate in the Devonian(?) age. The only positively iden- wacke and lenses of coquina in calcareous tified fossils are conodonts of Late Devo- sandstone both contain brachiopods, pele- nian (Famennian) age in an enigmatic cypods, crinoids, and corals of Late Devonian collection (No. 192, table 1) assigned to this (Frasnian) age. Thickness ranges from about unit because its coordinate location is in 400 ft to probably more than 1,000 ft the unit. Probably the conglomerate and shale Dbc Beaucoup Formation, conglomerate and shale member is Frasnian in age, like the rest of member (Upper Devonian)—Conglomer- the Beaucoup. The member is about 1,500 ate, sandstone, and shale with greenschist to 2,000 ft thick facies mineral assemblages interbedded in Dbl Beaucoup Formation, limestone member (Upper units 25 to 200 ft thick. Black, brown, and Devonian)—Consists mostly of medium- red-weathering sheared granule, pebble, and gray to black, fine-grained calcarenite, cobble conglomerate makes up from one calcisiltite, and calcilutite, thin bedded to third to two thirds of the member. Clasts slatey, that weather yellowish gray to or- are black, white, gray, green, and red chert, ange. Lesser amounts of light-gray to dark- chips of black slate, and, in the upper part gray, blocky, light-gray-weathering, very of the member, some chips of red and green fine grained calcarenite and calcilutite and

16 brown-weathering, very fine grained, Co. of California (Oliver and others, 1975) argillaceous limestone with a few interbeds at this locality may be from the structur- of black shale. Minor coarse crinoidal ally separated beds in the eastern part of limestone and dark-gray, fine-grained the outcrop area dolomite. Rare irregular nodules of re- Dbs Beaucoup Formation, siltstone member (Up- placement chert, silicified limestone, and per Devonian)—Brown and tan, micaceous, silicified fossils. Abundant rugose and slatey, calcareous siltstone and calcareous tabulate corals, atrypid, cyrtospiriferid, shale. Also includes greenish-gray to purple productellid, and strophomenid brachio- and black siltstone and slate interbedded pods, and conodonts; all of Late Devo- with thin beds of sandstone, conglomerate, nian (Frasnian) age. About 200 to 400 ft and limestone. Some brown-weathering, thick partly calcareous, sheared conglomerate |c Unnamed sheared conglomerate (Devonian?)— composed of pebbles of slate, chert, and red- Sheared conglomerate composed of pebbles weathering limestone in a matrix of grit and of white chert, some black chert, quartz, siltstone is also present. Interbedded in the quartzite, and black and purple slate. Larg- conglomerate is some dark-gray to black est pebbles are quartzite, 10 cm long. Chert and sooty, thin-bedded to platey limestone pebbles are flattened, stretched, recrys- that weathers yellow and orange and locally tallized, sugary-textured, sericitic, and lo- contains slate pebbles. Brachiopods and cally foliated, and display chloritoid on corals of Late Devonian (Frasnian) age occur the foliation surfaces. Conglomerate is in the calcareous shale. Thickness uncer- deeply weathered to loose, brittle plates tain, but is more than 500 ft of flattened yellow, white, and rusty DOs Skajit Limestone (Devonian, Silurian, and pebbles. Locally, no fresh rock is visible. Ordovician)—Light- to medium-gray, very Matrix of conglomerate is mostly very sili- fine grained to fine-grained, massive lime- ceous and partly calcareous; some is stone, recrystallized limestone, and coarse- shaley. Quartzite interbedded with the con- crystalline marble. Unit weathers gray and glomerate is purple and yellow; schistose yellowish gray. Includes minor black platey sandstone is purple, yellow, and green like crinoidal limestone, and dark-gray, fetid, the overlying Noatak Sandstone (Dn). Top argillaceous limestone that weather gray and may be interbedded with the Noatak Sand- orange; and rare chert and orange dolomite. stone. Stratigraphic position beneath the Unit is locally capped by layer of black chert Noatak is uncertain because many of the 1 to 2 ft thick. Contains conodonts of Late contacts are faults. Base not exposed. The Ordovician, probable Silurian, and pos- extreme shearing suggests that it may be sible Middle Devonian age and corals of a thrust fault. Thickness 1,000 ft or more. Ordovician to Late Devonian age. Con- No fossils found tains pentamerid brachiopods of Late(?) DSl Unnamed fossiliferous limestone (Upper and Silurian age 6 mi west of quadrangle Middle? Devonian and Upper? Silurian)— (Brosgé and others, 1979). Probably about Dark-gray, gray- and yellow-weathering, 2,000 ft thick; base not exposed fine-grained limestone with abundant co- lonial corals and stromatoporoids underlain Sheenjek Subterrane by gray calcilutite with sparry calcite (Mapped in southeast part of quadrangle, near Old patches, stromatoporoid layers, and a few Woman Creek) coral fragments. Exposed in a continuous sequence about 200 ft thick. A fault sepa- Jm Unnamed mafic rocks (Jurassic?)—Sills of rates these beds from 400 ft of similar beds, metamorphosed, dark-green, very fine crys- to the east, that may include some dupli- talline to medium-crystalline basalt. Com- cate section. Top beds of 200-ft section posed of clinopyroxene altered to chlorite contain brachiopods of Late Devonian and actinolite, plagioclase to kaolin, sphene (Frasnian?) age. Middle(?) Devonian cor- to leucoxene, with some celadonite and glass. als occur throughout the underlying fine- Consists of many separate sills; total thick- grained limestone. Corals of Late(?) Silurian ness more than 100 ft. Intruded between age collected by geologists of Standard Oil Lisburne Group limestone (Ml) and unnamed

17 chert and slate unit (&Mp), and contains written commun., 3/31/81) and conodonts inclusions of limestone, chert and slate; of Permian or Triassic age (Bruce Wardlaw, therefore age is younger than Mississippian. written commun., 3/12/79). Probable source Locally intrudes unnamed red and green of glassy black chert that has been worked argillite (^Pa), is therefore probably younger for tools at several sites than Triassic Dkq Kanayut Conglomerate, quartzite member (De- ^Pa Unnamed red and green argillite (Triassic vonian)—Light-gray, fine-grained quartzite through Permian)—Red and green argil- and dark-gray, fine-grained quartzite in beds lite. About 300 ft thick. No fossils found. about 6 in thick; contains slate chips. Similar rocks in same sequence and Thickness not known. No fossils found. subterrane (Silberling and others, 1992), Probably Devonian, according to apparent about 45 mi southeast in Coleen quadrangle, stratigraphic position and correlation with contain one possible Permian or Triassic Kanayut in Hammond Subterrane conodont (Brosgé and Reiser, 1969) Dw Unnamed wacke (Devonian?)—Dark-gray and &Mp Unnamed chert and slate (Pennsylvanian? medium-gray to gray-green and yellow- through Mississippian?)—Interbedded gray brown, fine-grained, thin-bedded, micaceous siliceous argillite and gray chert. Thickness wacke. Weathers orange and yellowish gray. about 100 ft or more. No fossils found. Contains slate chips and plant fragments. Probably same age as same unit in adja- Interbedded with about 50 percent black and cent Venetie Subterranes gray-brown shale. Probably 1,000 to 2,000 Ml Lisburne Group (Mississippian)—Limestone, ft thick. No fossils found, but same unit medium to dark gray, fine grained, sugary, in outcrops 7.5 mi and 10 mi south in laminated, partly to entirely silicified. About Christian quadrangle (Brosgé and Reiser, 50 to 100 ft thick. Underlain by 100 ft of 1962) contains spores of probable Early rusty brown chert. Contains conodonts of Devonian age (J.M. Schopf, written Early Mississippian age and foraminifera commun., 2/7/73) and plant fossils of prob- of Early or early Late Mississippian age. able Upper Devonian age (Mamay, 1962) Chert contains Mississippian radiolarians Dhf Hunt Fork Shale, shale member (Upper De- |ss Unnamed slate and siltstone (Upper Paleo- vonian)—Mostly black silty slate and shale zoic)—Black to gray slate, silty phyllite that weather yellowish gray; dark-gray, and siltstone; minor gray, fine-grained, very fine grained to fine-grained, brown- thin-bedded, partly calcareous quartz sand- weathering, thin-bedded to laminated sand- stone. Thickness not known. No fossils found stone with slate chips; minor light-gray quartzite. About 800 ft to 1,000 ft thick. Venetie Subterrane No fossils found; age inferred from strati- (Mapped in southeast part of quadrangle) graphic position and correlation with Hunt Fork of Hammond subterrane ^Ms Unnamed slate and chert (Triassic? through Mississippian)—Black to light-gray, lami- Venetie and Sheenjek Subterranes, undivided nated radiolarian chert that weathers purple, (A structural assemblage of parts of two subterranes, orange, and rusty; gray-green glassy chert mapped south of Junjik River and eastward to Old Woman that grades to silicified argillite; and Creek. See Plate 2 for location) interbedded green, red, and yellow, manganiferous, partly silicified argillite. ^Pa Unnamed red and green argillite and chert (Tri- Probably hundreds of feet thick. Black and assic? to Permian?)—Differentiated east green chert contains radiolarians of Mis- of the East Fork Chandalar River and a few sissippian age and latest Mississippian to places farther west. Green to yellowish-gray, earliest Pennsylvanian age. The slate and pyritic, manganiferous argillite and red, chert unit extends southward into the green, and purple, partly silicified, pyritic, Christian quadrangle where chert in red and manganiferous clay shale, and slate and silty green shale that crops out only about 3 mi slate. Argillite grades vertically into glassy, to the south (Brosgé and Reiser, 1962) green, radiolarian, spicular(?), locally barite- contains radiolarians of Mesozoic (or bearing chert that makes up less than one younger) age (D.L. Jones and B.L. Murchey, fourth of the unit. Locally interbedded with

18 rusty weathering shale and siltstone at |ss Unnamed slate and siltstone (Upper Paleo- contacts with adjacent unit &Mp. No fos- zoic)—Dark-gray and black shale, slate, and sils identified. Probably about 300 ft thick shaley siltstone that is partly manganiferous ^Ms Unnamed slate and chert (Triassic? through and rusty weathering and partly siliceous Mississippian)—Black slate and chert, and and white weathering. Includes minor gray- red and green argillite and chert. Most of green manganiferous slate and argillite and the red and green rocks are mapped as a some dark-gray and gray-green, very fine separate unit (^Pa) east of the East Fork grained to fine-grained, thin-bedded, slightly Chandalar River and locally to the west. calcareous, foliated quartz wacke and lithic Siliceous manganiferous black slate and wacke with rare biotite clasts. Probably 500 black shaley siltstone in units 50 to 800 ft to 1,000 ft thick. No fossils found. Strati- thick make up about one half of the undif- graphic position uncertain ferentiated unit. About one fourth is black Dw Unnamed wacke (Devonian)—Mostly black shale and gray, glassy to silty, partly pyritic, radi- and siltstone, and about one third lithic olarian chert, some in thin beds interbedded wacke, quartz wacke, and quartzite. Char- in slate and grading into silicified slate; some acterized by yellow-brown weathering and in beds and lenses as much as 50 to 100 ft by abundant unidentifiable plant fragments. thick. Beds and lenses of red and green and Fine-grained rocks consist of micaceous clay gray-green manganiferous argillite and chert and silt shale, slate, and laminated siltstone make up the rest of the unit. Some black slate and display flow marks, cone-in-cone struc- contains ironstone nodules and minor black tures, and nodules and thin beds of iron- and gray, very fine grained, nodular to lami- stone. Shale forms thin partings in the wacke, nated sandstone. Black chert and the vari- and also forms layers 10 to 100 ft thick. colored argillite contain veins and lenses of Most of the wacke is lithic wacke; it is barite. About 1,000 to 1,500 ft thick. Con- medium to dark gray and greenish gray, very tains Mississippian, Late Mississippian to fine to medium grained, thin to medium bed- Pennsylvanian, and Late Triassic radiolar- ded, micaceous, partly manganiferous, and ians. The lower part of this unit is probably locally foliated. It weathers yellow, orange, equivalent to unit (&Mp), but contains more olive, and brown, and contains shale chips, chert load casts, a few quartz pebbles, and many Pl Unnamed limestone (Permian?)—Interbedded plant fragments. The remaining quartz-rich light-brown, reddish-weathering, sandy wacke is medium gray to gray-green, fine limestone and irregular beds of gray-green, grained, thin to thick bedded, partly sili- brown-weathering, fine-grained, very cal- ceous, and partly limonitic. It weathers white, careous sandstone with minor black shale. gray, and brown and contains shale and About 500 ft thick. No fossils found. sandstone chips, flow marks, and wood Resembles the lower Echooka Formation fragments. The wacke forms layers 10 to of North Slope Subterrane. Mapped only 20 ft thick consisting of fining-upward cycles at one locality near Old Woman Creek 6 to 12 in thick. Unit is probably about 1,500 &Mp Unnamed phyllite and chert (Pennsylvanian? to 2,000 ft thick. Contains spores of Late(?) and Mississippian)—Mostly dark-gray to Devonian age black phyllite, slate, and siltstone. Slate is locally silicified and grades to black fis- Endicott Mountains and Venetie Subterranes, undivided sile chert. Contains rare beds of white, gray, (A structural assemblage of parts of two subterranes, and black chert. Siltstone is shaley, mica- mapped north of the Junjik River and Nichenthraw ceous, rusty weathering, and partly calcar- Mountain. See Plate 2 for location) eous. Includes some interbedded gray-green, pyritic, manganiferous slate and argillite. Kk? Kongakut Formation? (Lower Cretaceous?)— Minor gray and black, fine-grained, calcar- Black manganiferous shale and phyllite, and eous wacke composed of quartz, chert, rock black, very fine grained, medium-bedded, fragments, plagioclase, biotite, and some partly calcareous lithic wacke that weath- microperthite(?) grains. Probably 500 to ers brown and orange. Wacke contains rare 1,000 ft thick. Contains radiolarians of clasts of biotite and glaucophane. Probably Mississippian age about 600 to 1,000 ft thick. No fossils found.

19 Topography and weathering characters De Long Mountains Subterrane suggest correlation with fossiliferous (South of Junjik River) Kongakut Formation assigned to the Endicott Mountains Subterrane near Mount Annette P&i Imnaitchiak Chert (Permian and Pennsylva- ^Pss Sadlerochit Group and Siksikpuk Formation?, nian)—Chert, argillite, and silty shale. Chert undifferentiated (Lower Triassic and Per- is light green, weathers white and rusty; mian)—Black and dark-gray micaceous minor gray, black, and red chert. Argillite manganiferous shale; olive and green-brown- is maroon, red, and green and manganiferous; weathering, non-calcareous, manganiferous silty shale is gray, pyritic. More than 500 shale; minor black, very fine grained, orange- ft thick. Contains radiolarians of Missis- weathering sandstone. Black massive radi- sippian or Pennsylvanian age and radiolarians olarian chert is locally interbedded with green of Pennsylvanian or Permian age shale in intervals 100 ft thick. Chert con- &Ma Akmalik Chert (Pennsylvanian and Mississip- tains thin layers of dolomite and silicified pian)—Black chert, some dull and silty, limestone and radiolarians of Permian(?) some glassy; mostly massive, some lami- age. Thickness not known nated. Unit locally includes a thin bed of ^Ms Unnamed slate and chert (Triassic? to Mis- dark-gray recrystallized limestone and rubble sissippian)—Red and green slate and chert of ferruginous limestone and calcareous silt- and black chert and slate. About 50 per- stone. About 250 ft thick. Chert contains cent of unit is red and green manganiferous radiolarians that are probably of Late Mis- slate, shale, and silicified argillite, green sissippian age. Brachiopods of Early Mis- and brown siltstone, and orange-weathering sissippian age were found in an adjacent green chert with layers of hematitic dolo- small body of crinoidal limestone that might mite. About 40 percent is black radiolar- represent a small fault sliver of Kayak Shale ian chert and some gray laminated chert; Ml Lisburne Group (Mississippian)—Light-gray, also includes one bed of barite. Black and medium- to coarse-grained crinoidal lime- gray slate and silty shale with rare calcar- stone. Limestone is largely silicified or eous shale and brown-weathering quartz- replaced by gray and white blocky chert in itic siltstone compose rest of unit. About zones deposited along and normal to bed- 500 ft thick. Contains Late Mississippian ding. Probably only a few hundred feet thick; or Early Pennsylvanian radiolarians locally absent. Basal beds contain brachio- Ps Siksikpuk Formation (Permian)—Olive-gray pods of Early Mississippian age. May be silicified siltstone, weathers white. Mapped entirely Early Mississippian if the overly- at one locality ing Akmalik Chert is entirely Late and &Mk Kuna Formation (Pennsylvanian? and Missis- younger Mississippian sippian)—Black shale and black, fine- Mk Kayak Shale (Lower Mississippian)—Black shale grained sooty limestone. Only about 100 with ironstone concretions and yellow- ft to 200 ft exposed. Contains ammonite of weathering lenses of crinoidal limestone. Late Mississippian age. Recognized at one Locally includes a basal quartzite that is locality north of Nichenthraw Mountain as much as 100 ft thick. Contains brachio- &c Unnamed chert (Pennsylvanian?)—Thick-bedded pods of Early Mississippian age. Probably black chert. Rests on Lisburne Group Lime- about 500 ft thick stone of early Late Mississippian age Dbw Beaucoup Formation, wacke member (Upper Ml Lisburne Group (Mississippian)—Gray, partially Devonian)—Gray, fine- to medium-grained, silicified limestone with black nodular chert; thin-bedded, ferruginous quartzite and quartz light-gray calcilutite with light-gray chert. wacke that contain ironstone chips and some Contains foraminifera of early Late Mis- granules of quartz, chert, and slate. Wacke sissippian age. Probably also includes beds is black, very fine grained, orange and gray of Early Mississippian age. Thickness not weathering, and forms thin, graded beds that known; probably 1,000 to 1,500 ft are interbedded with black, manganiferous clay shale and silty shale. Lenses of orange- Mk Kayak Shale (Mississippian)—Black shale and weathering, calcareous sandstone contain yellow-weathering crinoidal limestone. brachiopods and corals of Late Devonian Thickness not known. Contains brachiopods (Frasnian) age. Probably about 1,000 ft thick of Early(?) Mississippian (Osagian?) age

20 Klippen of Endicott Mountains and De Long Mountains calcilutite, in beds as thick as 4 in, and weathers Subterranes and Tozitna(?) Terrane near Mount Annette cream-colored to light brown. Monotid pele- cypods of Late Triassic (Norian) age are [Nearly all faults mapped in the klippen are thrust faults, although level of detail on the map precludes addition of sawteeth] abundant in all of the limestones. At one locality, a thick chert bed that is overlain Kk Kongakut Formation (Lower Cretaceous)— by monotid-bearing limestone contains Black and gray-green, manganiferous, mi- radiolarians of Late Triassic age and con- caceous silt shale that weathers gray-green odonts of Early Triassic (Smithian?) age. and brown and contains manganese nod- Thickness probably 300 ft or more ules. Interbedded black and brown, very fine ^Pe Etivluk Group (Triassic through Permian?)— grained to fine-grained manganiferous lithic Mostly radiolarian chert with lesser shale wacke that weathers green, brown, and and siltstone and rare beds of limestone. orange. Rhythmically bedded in cycles 6 to Most chert is black to brown, thick bed- 12 in thick. Minor hard, black, manganiferous, ded, and weathers brown to rusty orange; micaceous siltstone with manganese nodules. about one third is gray-green and weath- Contains minor black, soft clay shale with ers silver gray. Shale is black to dark gray, ironstone concretions that have 1- to 2-in- silty, hard, manganiferous, and rusty- to diameter cores of phosphatic chert. Thickness brown-weathering; silty shale is gray-green. at least 500 ft. Contains spores of probable Includes some silicified siltstone that grades Cretaceous age and foraminifera of Early into brown-weathering chert. Also contains Cretaceous (Neocomian) age. Correlated with rare gray, platy, creamy-weathering the black manganiferous shale and fine- calcilutite in 5- to 10-ft-thick layers, and grained graywacke of the Kongakut For- beds and lenses of black sooty limestone mation in the northern part of the adjacent and fine-grained, silty, orange-weathering Philip Smith Mountains quadrangle (Brosgé limestone in black shale. Mapped in most and others, 1979) rather than with the coarser of area mainly by the light- and dark-brown graywacke and conglomerate of the rubble slopes. Traversed completely only Neocomian Okpikruak Formation in the on Mount Annette. Thickness is about 300 southern part of that quadrangle ft. Contains monotid pelecypods and radi- ^Pv Unnamed volcanic rocks (Triassic and Per- olarians of Late Triassic age mian)—Basalt, andesite, and chert. Basalt ^Mi Imnaitchiak Chert (Triassic through Missis- is coarse crystalline, sheared, slickensided, sippian)—Gray-green and olive, laminated and altered to chlorite, clay, and epidote. siltstone, silty argillite, and silicified silt- Andesite is mostly medium crystalline, rusty stone that grades to chert. Forms layers 50 weathering; lower part of andesite is fine to 100 ft thick. Interbedded gray and gray- crystalline; contains amygdules of chlorite, green radiolarian chert that weathers white, calcite, prehnite, and pumpelleyite(?) and olive, and gray-brown. Also includes a few contains a 25-ft-thick zone of gray and brown 10-ft-thick beds and lenses of medium-gray, silty chert. A few feet above the base of orange-weathering calcilutite, brown limestone, unit is a 5-ft-thick bed of dark-gray, fine- and calcareous siltstone. The limestones grained, brown-weathering, sandy limestone throughout the unit contain monotid pelecy- that contains crinoids and clasts of lime- pods of Late Triassic (Norian) age. Olive and stone, plagioclase, and probably sheared black chert at the base of the unit contains volcanic rock. This bed also contains cor- radiolarians of Mississippian or Pennsylva- als and brachiopods of Late Permian age nian age. Chert higher in the unit contains and foraminifera of Permian or younger age. radiolarians of Permian(?) age; and, near the Radiolarians of Late Triassic age are present top of the unit chert contains radiolarians of in the chert. Thickness is more than 300 Late Triassic age. About 400 ft thick ft. Resembles rocks of the Tozitna Terrane &Ma Akmalik Chert (Pennsylvanian and Mississip- south of the Arctic quadrangle pian)—Black, silty to glassy, pyritic chert, ^o Otuk Formation (Triassic)—Black clay and silt bedded and laminated. In lower part is a thin shale interbedded with limestone and with black, bed of black limestone and rubble of gray gray, and brown radiolarian chert that con- recrystallized limestone and recrystallized tains some beds of olive-gray calcilutite. hematitic dolomite. About 75 ft thick. Limestone Limestone in the shale is gray to black contains conodonts of Late Mississippian age

21 REFERENCES CITED ———1962, Paleozoic sequence in eastern Brooks Range, Alaska: American Association of Petroleum Geologists Adams, K.E., and Siok, J.P., 1989, Permian stratigraphy in Bulletin, v. 46, no. 12, p. 2174Ð2198. the Atigun Gorge area: a transition between the Echooka Brosgé, W.P., and Reiser, H.N., 1962, Preliminary geologic and Siksikpuk Formations, in Mull, C.G., and Adams, map of the Christian quadrangle, Alaska: U.S. Geologi- K.E., eds., Dalton Highway, Yukon River to Prudhoe cal Survey Open-File Map 62Ð15, 2 sheets, scale Bay, Alaska: Alaska Division of Geological and Geo- 1:250,000. physical Surveys Guidebook 7, v. 2, p. 267Ð275. ———1965, Preliminary geologic map of the Arctic quad- Anderson, A.V., 1991a, Geologic map and cross-section: rangle, Alaska: U.S. Geological Survey Open-File Re- Headwaters of the Kongakut and Aichillik Rivers, De- port 65Ð22, scale 1:250,000. marcation Point (AÐ4) and Table Mountain (DÐ4) quad- ———1969, Preliminary geologic map of the Coleen quad- rangles, eastern Brooks Range, Alaska: Alaska Division rangle, Alaska: U.S. Geological Survey Open-File Re- of Geological and Geophysical Surveys Public-data file port 69Ð25, scale 1:250,000. 91Ð3, 23 p., scale 1:25,000. 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22 1975, Post-Carboniferous stratigraphy, northeastern Alaska: 143Ð186. U.S. Geological Survey Professional Paper 886, 46 p. Menzie, W.D., Reiser, H.N., Brosgé, W.P., and Detterman, Dover, J.H., 1994, Geology of part of east-central Alaska, in R.L., 1985, Map showing distribution of mineral re- Plafker, George, and Berg, H.C., eds., The geology of sources (excepting oil and gas) in the Philip Smith Moun- Alaska: Boulder, Colo., Geological Society of America, tains quadrangle, Alaska: U.S. Geological Survey Mis- The Geology of North America, v. GÐ1, p. 53Ð204. cellaneous Field Studies Map MFÐ879ÐC, 1 sheet, scale Dusel-Bacon, Cynthia, Brosgé, W.P., Till, A.B., Doyle, E.O., 1:250,000. Mayfield, C.F., Reiser, H.N., and Miller, T.P., 1989, Dis- Mertie, J.B., Jr., 1930, The Chandalar-Sheenjek district, tribution, facies, ages, and proposed tectonic associa- Alaska: U.S. Geological Survey Bulletin 810, p. 87Ð139, tions of regionally metamorphosed rocks in northern scale 1:500,000. 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Creek allochthon, Killik River quadrangle, central Mamay, S.H., 1962, Occurrence of Pseudobornia Nathorst Brooks Range, Alaska: a summary, in Tailleur, Irv, and in Alaska: Paleobotanist, v. 11, no. 1/2, p. 19Ð22. Weimer, Paul, eds., Alaskan North Slope geology: Mamet, B.L., and Armstrong, A.K., 1972, Lisburne Group, Bakersfield, Calif., Society of Economic Paleontologists Franklin and Romanzof Mountains, northeastern Alaska: and Mineralogists, Pacific Section, and Alaska Geologi- U.S. Geological Survey Professional Paper 800ÐC, p. cal Society, Book 50, v. 2, p. 649Ð662. C27ÐC124. Mull, C.G., Tailleur, I.L., Mayfield, C.F., Ellersieck, I.F., and Martin, A.J., 1970, Structure and tectonic history of the west- Curtis, S., 1982, New upper Paleozoic and lower Meso- ern Brooks Range, De Long Mountains and Lisburne zoic stratigraphic units, central and western Brooks Hills, northern Alaska: Geological Society of America Range, Alaska: American Association of Petroleum Bulletin, v. 81, no. 12, p. 3605Ð3621. Geologists Bulletin, v. 66, no. 3, p. 348Ð362. Mayfield, C.F., Tailleur, I.L., and Ellersieck, Inyo, 1988, Nilsen, T.H., Moore, T.E., Dutro, J.T., Jr., Brosgé, W.P., and Stratigraphy, structure and palinspastic synthesis of Orchard, D.M., 1980a, Sedimentology and stratigraphy the western Brooks Range, northwestern Alaska, in of the Kanayut Conglomerate and associated units, cen- Gryc, George, ed., Geology and exploration of the tral and eastern Brooks Range, Alaska—Report of the National Petroleum Reserve in Alaska, 1974 to 1982: 1978 field season: U.S. Geological Survey Open-File U.S. Geological Survey Professional Paper 1399, p. Report 80Ð888, 40 p.

23 Nilsen, T.H., Moore, T.E., and Brosgé, W.P., 1980b, No. 4 and adjacent areas, northern Alaska: U.S. Geo- Paleocurrent maps for the Upper Devonian and Lower logical Survey Professional Paper 301, 192 p. Mississippian Endicott Group, Brooks Range, Alaska: Reiser, H.N., Brosgé, W.P., Dutro, J.T., Jr., and Detterman, U.S. Geological Survey Open-File Report 80Ð1066, R.L., 1971, Preliminary geologic map, Mt. Michelson scale 1:1,000,000. quadrangle, Alaska: U.S. Geological Survey Open-File Nilsen, T.H., Moore, T.E., Brosgé, W.P., and Dutro, J.T., Jr., Report 71Ð237, scale 1:200,000. 1981, Sedimentology and stratigraphy of the Kanayut ———1974, Preliminary geologic map of the Demarcation Conglomerate and associated units, Brooks Range, Point quadrangle, Alaska: U.S. Geological Survey Mis- Alaska—Report of 1979 field season: U.S. Geological cellaneous Field Studies Map MFÐ610, scale 1:250,000. Survey Open-File Report 81Ð506, 37 p. Silberling, N.J., Jones, D.L., Monger, J.W.H., and Coney, Nilsen, T.H., Moore, T.E., Balin, D.F., and Johnson, S.Y., P.J., 1992, Lithotectonic terrane map of the North 1982, Sedimentology and stratigraphy of the Kanayut American Cordillera: U.S. Geological Survey Miscel- Conglomerate, central Brooks Range, Alaska—Report laneous Investigations Series Map IÐ2176, 2 sheets, of 1980 field season: U.S. Geological Survey Open- scale 1:5,000,000. File Report 82Ð199, 81 p. Snelson, Sigmund, and Tailleur, I.L., 1968, Large-scale Nilsen, T.H., and Moore, T.E., 1984, Stratigraphic nomen- thrusting and migrating Cretaceous foredeeps in west- clature for the Upper Devonian and Lower Mississip- ern Brooks Range and adjacent regions of northwest- pian(?) Kanayut Conglomerate, Brooks Range, Alaska: ern Alaska [abs.]: American Association of Petroleum U.S. Geological Survey Bulletin 1529ÐA, 64 p. Geologists Bulletin, v. 52, no. 3, p. 567. Nokleberg, W.J., Moll-Stalcup, E.J., Miller, T.P., Brew, D.A., Tourtelot, H.A., and Tailleur, I.L., 1971, The Shublik For- Grantz, Arthur, Reed, J.C., Jr., Plafker, George, Moore, mation and adjacent strata in northeastern Alaska: De- T.E., Silva, S.R., and Patton, W.W., Jr., 1994, Tectono- scription, minor elements, depositional environments, stratigraphic terrane and overlap assemblage map of and diagenesis: U.S. Geological Survey Open-File Re- Alaska: U.S. Geological Survey Open-File Report port 71Ð284, 62 p. 94Ð194, 53 p., 1 sheet, scale 1:2,500,000. Wallace, W.K., and Hanks, C.L., 1990, Structural provinces Oldow, J.S., Seidensticker, C.M., Phelps, J.C., Julian, F.E., of the northeastern Brooks Range, Arctic National Wild- Gottschalk, R.R., Boler, K.W., Handschy, J.W., and Avé life Refuge, Alaska: American Association of Petroleum Lallemant, H.G., 1987, Balanced cross-sections through Geologists Bulletin, v. 74, no. 7, p. 1100Ð1118. the central Brooks Range, and North Slope, Arctic Watts, K.F., 1989, Stratigraphy and paleogeographic sig- Alaska: Tulsa, Okla., American Association of Petro- nificance of the Carboniferous Wahoo Limestone—re- leum Geologists, 19 p., scale 1:200,000. examination of the type section, northeastern Brooks Oliver, W.A., Jr., Merriam, C.W., and Churkin, Michael, Jr., Range, Alaska [abs.]: Geological Society of America, 1975, Ordovician, Silurian, and Devonian corals of Abstracts with Programs, v. 21, no. 5, p. 157. Alaska: U.S. Geological Survey Professional Paper Williams, J.R., 1962, Geologic reconnaissance of the Yukon 823ÐB, 44 p., 25 plates. Flats district, Alaska: U.S. Geological Survey Bulletin Patton, W.W., Jr., and Box, S.E., 1989, Tectonic setting of 1111ÐH, p. 289Ð331. the Yukon-Koyukuk basin and its borderlands: Journal Yeend, Warren, and Brosgé, W.P., 1973a, Preliminary geo- of Geophysical Research, v. 94, no. B11, p. 15807Ð logic map of a prospective transportation route from 15820. Prudhoe Bay, Alaska to Canadian border, Part III, Arc- Peace, J.L., 1979, Geology and mineral occurrences of the tic quadrangle (north half), Alaska: U.S. Geological Porcupine Lake area, northeastern Brooks Range, Survey Miscellaneous Field Studies Map MFÐ501, 2 Alaska: Fairbanks, Alaska, University of Alaska, sheets, scale 1:125,000. Master’s thesis, 72 p. ———1973b, Preliminary geologic map of a prospective Read, C.B., and Mamet, S.H., 1964, Upper Paleozoic floral transportation route from Prudhoe Bay, Alaska to Ca- zones and floral provinces of the United States: U.S. nadian border, Part IV, Arctic and Table Mountain quad- Geological Survey Professional Paper 454ÐK, 35 p. rangles: U.S. Geological Survey Miscellaneous Field Reed, J.C., 1958, Exploration of Naval Petroleum Reserve Studies Map MFÐ522, 2 sheets, scale 1:125,000.

24 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska [Fossils identified by: Armstrong, A.K.; Carter, Claire; Dutro, J.T., Jr.; Gordon, Mackenzie, Jr.; Grant, R.E.; Haga, Hideyo; Harris, A.G.; Hazel, J.E.; Holdsworth, B.K.; Hueber, F.M.; Jones, D.L.; Kummel, Bernhard; Mamay, S.H.; Mamet, B.L.; Mickey, M.B.; Miller, J.W.; Murchey, B.L.; Nichols, K.M.; Oliver, W.A., Jr.; Pojeta, John, Jr.; Silberling, N.J.; Taylor, D.W.; Tailleur, I.L.;Wardlaw, B.R.; and Yochelson, E.L. Identification of graptolites and some corals published in Moore and Churkin, 1984, and Oliver, 1975]

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Quaternary Deposits, undifferentiated (Qu) 182 M-2989 66ABe291 68° 08' N pelecypods Pleistocene or younger Taylor 2/24/67 145° 32' W gastropods (freshwater) 183 M-2988 66ABe289A 68° 10' N pelecypods Pleistocene or younger Taylor 2/24/67 145° 30' W gastropods Hazel 4/6/67 ostracodes (freshwater) Cretaceous Rocks, Ipewik unit (Ki) 23 M-7920 82ATr48A 68° 46' N pelecypods Early Cretaceous (Valanginian) Miller 2/27/84 146° 36' W 24 82ATr40 68° 46' N pelecypod coquina Cretaceous Tailleur 1982 field 146° 30' W ident. Cretaceous Rocks, Kongakut Formation (Kk) 30 78ABe50A 68° 46' N spores Cretaceous(?) Haga 9/12/80 145° 56' W 39 82ATr37 68° 44' N foraminifers Early Cretaceous (Neocomian) Mickey 10/82 146° 27' W Triassic Rocks, Shublik Formation (^s ) 15 68ATo11 68° 48' N pelecypods Late Triassic (Karnian) Silberling 10/28/68 146° 32' W 16 Mes 32762 82ATr36 68° 48' N conodonts Late Middle through Late Wardlaw, Harris 146° 25' W Triassic 12/15/82 16 Meso D12064 82ABe633 68° 48' N ammonites Late Triassic (Late Karnian) Silberling 12/29/82 146° 25' W pelecypods 17 72ABe283A 68° 48' N ammonites Indeterminate Silberling, Nichols 146° 09' W 3/13/73 17 72ABe283B 68° 48' N pelecypods Late Triassic (Karnian or early Silberling, Nichols 146° 09' W Norian) 3/13/73 18 72ABe280 68° 48' N pelecypods Late Triassic (Karnian or early Silberling, Nichols 145° 57' W Norian) 3/13/73 19 M-5065 68ATo12 68° 47' N pelecypods Late Triassic (Late Karnian) Silberling 10/28/68 146° 28' W ammonites 22 Meso D12059 82ABe601A 68° 47' N ammonite Middle Triassic or younger Silberling 10/29/82 146° 37' W 26 72ABe316A 68° 47' N pelecypods Late Triassic (Karnian or early Silberling, Nichols 146° 23' W Norian) 3/13/73 Triassic Rocks, Otuk Formation (^o) 21 72ABe284C 68° 47' N pelecypods Late Triassic (Late Norian?) Silberling, Nichols 146° 12' W 3/13/73 27 68ATr13 68° 46' N pelecypods Late Triassic (Late Norian) Silberling 5/14/69 146° 28' W

* Map numbers refer to locations shown on map sheet 2. ** All USGS Locality Numbers refer to the several catalogues maintained in the four USGS Paleontology and Stratigraphy Branch centers. Prefix abbreviations: M, general catalogue in Menlo Park, CA; Mes, Mesozoic catalogue in Reston, VA; Meso D, Mesozoic catalogue in Denver, CO; USGS MR, radiolarian catalogue in Menlo Park, CA. Suffix abbreviations: Mz, Mesozoic catalogue in Reston, VA; PC, Late Paleozoic catalogue in Washington, D.C. (partially computerized in Denver, CO); SD, Silurian-Devonian catalogue in Reston, VA. 25 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Triassic Rocks, Otuk Formation (^o)—cont. 33 Meso D12062 82ABe605B1 68° 46' N pelecypods Late Triassic (Late Norian) Silberling 12/29/82 146° 30' W 33 Meso D12063 82ABe605B2 68° 46' N pelecypods Late Triassic (Late Norian) Silberling 12/29/82 146° 30' W 33 82ATr14C 68° 46' N radiolarians Late Triassic Murchey 6/15/83 146° 30' W 33 Mes 32768 82ATr14-C 68° 46' N conodonts CAI Early Triassic (Smithian?) Harris, Wardlaw 146° 30' W 4.5-5 12/28/82 116 72ABe297 68° 22' N pelecypods Mixed Middle and Late Triassic Silberling, Nichols 146° 02' W (Ladinian and Karnian) 3/13/73 117 72ABe298C 68° 22' N pelecypods Late Triassic (Late Norian?) Silberling, Nichols 146° 02' W 3/13/73 Triassic and Permian Rocks, Etivluk Group (^Pe) (Otuk and Siksikpuk Formations, undivided) 28 82ATr15A2 68° 46' N radiolarians Triassic Murchey 6/15/83 146° 29' W 34 82ATr14B 68° 45' N radiolarians Late Triassic Murchey 6/15/83 146° 30' W 38 72ABe314 68° 45' N pelecypods Late Triassic (Norian) Silberling, Nichols 146° 29' W 3/13/73 Triassic and Permian Rocks, Sadlerochit Group (^Ps) (Ivishak and Echooka Formations, undivided) 14 52ADu48 68° 49' N cephalopods Early Triassic (Scythian) Kummel 4/12/54 146° 25' W 20 24062 Mz 52ADu52 68° 47' N pelecypods Middle Early Triassic Silberling, Nichols 146° 33' W 5/10/73 20 24063 Mz 52ABe32 68° 47' N pelecypods Middle Early Triassic Silberling, Nichols 146° 33' W (Smithian) 5/10/73 22 24061 Mz 52ADu47 68° 47' N pelecypods Middle Early Triassic Silberling, Nichols 146° 37' W 5/10/73 22 Meso D12060 82ABe601-B 68° 47' N pelecypods Middle Early Triassic Silberling 12/29/82 146° 37' W (Smithian) 25 24064 Mz 52ABe43 68° 46' N pelecypods Middle Early Triassic Silberling, Nichols 146° 31' W (Smithian) 5/10/73 26 72ABe316B 68° 47' N pelecypods Indeterminate Silberling, Nichols 146° 23' W 3/13/73 31 82ATr14D 68° 45' N foraminifers Probably Permian or Triassic Mickey 10/82 146° 31' W 32 Mes 32763 82ATr19B 68° 45' N conodonts Middle Early Triassic (Middle Wardlaw, Harris 146° 31' W Smithian) 11/17/82 Triassic and Permian Rocks, Sadlerochit and Siksikpuk Formation, undivided (^Pss) 41 23571-PC 72ABe275C 68° 46' N brachiopods Early(?) Permian Dutro 2/13/73 145° 26' W 42 72ABe274 68° 44' N goniatitacid Late Paleozoic Silberling, Nichols 145° 20' W ammonite 3/13/73 43 23572-PC 72ARR253B 68° 48' N brachiopods Early(?) Permian Dutro 2/13/73 145° 07' W 44 79ADt 204 unit 1 68° 49' N brachiopods Early Permian Dutro 3/15/82 144° 56' W ammonoid 44 79ADt204 unit 2 68° 49' N brachiopods Early Permian Dutro 3/15/82 144° 56' W ammonoid 47 23570-PC 72ABe272B 68° 42' N brachiopods Early(?) Permian Dutro 2/13/73 145° 22' W 57 78ABe55B 68° 38' N cephalopods Indeterminate Dutro 6/88 145° 46' W

26 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Triassic and Permian Rocks, Sadlerochit and Siksikpuk Formation, undivided (^Pss)—cont. 58 USGS 79ADt200-2 68° 35' N radiolarians Late Paleozoic(?) Jones, Murchey MR1101 (200-U2) 145° 49' W 3/31/81 59 79ABe216B 68° 35' N big gastropod Early Permian Dutro 6/90 145° 45' W 62 23573-PC 72ARR258 68° 38' N brachiopods Early(?)Permian Dutro 2/13/73 144° 30' W 83 78ARR27A 68° 30' N foraminifer (one) Not reported Murchey 3/30/79 145° 17' W 90 USGS 78ARR19 68° 28' N radiolarians Permian(?) Jones, Murchey MR0524 145° 27' W 3/30/79 104 79ABe154 68° 24' N brachiopods Early Permian Dutro 6/88 146° 54' W gastropods 115 79ADt201 unit 1 68° 22' N brachiopods Early Permian Dutro 3/5/82 146° 05' W Triassic and Permian volcanic rocks (^Pv) 29 23583-PC 72ABe285 68° 46' N brachiopods Late Paleozoic Dutro 2/15/73 146° 12' W 29 M-1059 72ABe285B 68° 46' N foraminifers Permian or younger Armstrong 12/6/72 146° 12' W 29 M-1059 72ABe285B 68° 46' N corals (bryozoans) Paleozoic Armstrong 12/6/72 146° 12' W (crinoids) 29 27430-PC 75ABe91 68° 46' N brachiopods Late Permian Dutro 3/2/79 146° 11' W 29 82ATr17A 68° 46' N radiolarians Late Triassic Murchey 6/15/83 146° 12' W 29 82ATr17B 17C 68° 46' N foraminifers Latest Mississippian or Mamet 2/6/83 146° 12' W considerably younger Triassic, Permian(?), and Carboniferous Rocks, Imnaitchiak Chert, (^Mi) 28 82ATr15A1 68° 46' N radiolarians Latest Mississippian or earliest Murchey 6/15/83 146° 29' W Pennsylvanian 35 Meso D12061 82ABe604A 68° 45' N pelecypods Late Triassic (Middle Norian) Silberling 12/29/82 146° 29' W 35 82ATr13F 68° 45' N conodont Permian or Triassic Murchey 6/15/83 146° 29' W fragments 35 68ATr14A2 68° 45' N radiolarians (poor) Permian(?) Murchey 6/15/83 146° 29' W coiled foraminifers 35 72ABe312B 68° 45' N pelecypods Late Triassic (Middle or Late Silberling, Nichols 146° 29' W Norian) 3/13/73 36 82ATr13D 68° 45' N radiolarians Late Triassic Murchey 6/15/83 146° 29' W Triassic(?) to Mississippian Rocks, unnamed shale and chert (^Ms) 81 USGS 79ADt206-3 68° 31' N radiolarians Late Mississippian to Early Jones, Murchey MR1103 145° 16' W Pennsylvanian 3/31/81 82 USGS 79ADt208 68° 30' N radiolarians Late Mississippian to Early Jones, Murchey MR1104 145° 15' W Pennsylvanian 3/31/81 118 82ATr50G 68° 21' N radiolarians Late Triassic Murchey(?) 6/15/83 146° 06' W 203 60ABe588 68° 03' N radiolarians Mississippian (Latest?) to Holdsworth 3/5/79 145° 19' W Earliest? Pennsylvanian 204 60ABe589 68° 02' N radiolarians Mississippian Holdsworth 9/17/78, 145° 18' W 3/5/79 206 60ABe591D 68° 01' N radiolarians Mississippian probably Late Holdsworth 3/5/79, 145° 19' W Chesterian 9/17/78

27 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Permian Rocks, Echooka Formation (Pe) 79 79ADt206 unit 1 68° 31' N brachiopods Early Permian Dutro 3/5/82 145° 15' W gastropod 80 60ABe728 68° 31' N gastropods Early(?) Permian Dutro 1/25/62 145° 16' W 122 23342-PC 66ABe298 68° 22' N brachiopods Permian Dutro 6/24/68 145° 49' W gastropods 124 23574-PC 72ABe288C 68° 20' N crinoids Paleozoic Dutro 2/13/73 145° 50' W brachiopods(?) 124 72ABe288D 68° 20' N brachiopod Indeterminate Dutro 2/13/73 145° 50' W fragments 124 72ABe288E 68° 20' N brachiopod Indeterminate Silberling, Nichols 145° 50' W 3/13/73 Permian and Pennsylvanian Rocks, Imnaitchiak Chert (P&i) 109 USGS 79ARR1-A 68° 17' N radiolarians Pennsylvanian to Early Permian Jones, Murchey MR1093 146° 45' W 3/31/81 109 USGS 79ARR1-B 68° 17' N radiolarians Late Mississippian to Early Jones, Murchey MR1092 146° 45' W Pennsylvanian 3/31/81 Pennsylvanian and Mississippian Rocks, Lisburne Group, Akmalik Chert (&Ma) 37 28152-PC 82ATr13C 68° 45' N conodonts CAI 4 Late Mississippian (Late Harris 11/22/82 146° 28' W Meramec to Chester) 109 USGS 79ARR1-D 68° 17' N radiolarians Late Mississippian to Permian Jones, Murchey MR1094 146° 46' W (Late Miss.?) 3/31/81 111 USGS 79ABe141-C 68° 17' N radiolarians Late Mississippian to Early Jones, Murchey MR1078 146° 41' W Permian (Late Miss.(?)) 3/31/81 112 60ABe761 68° 16' N brachiopods Early Mississippian Dutro 12/11/61 146° 41' W Pennsylvanian and Mississippian Rocks, Lisburne Group, Kuna Formation (&Mk) 91 21328-PC 63ABe153 68° 28' N ammonite Late Mississippian Gordon 9/4/63 145° 18' W Pennsylvanian(?) and Mississippian Rocks, unnamed, phyllite, and chert (&Mp) 85 78ARR29A 68° 30' N radiolarians Mississippian Jones, Murchey 144° 26' W 3/30/79 86 78ARR33A,B 68° 29' N radiolarians Mississippian(?) to Jones, Murchey 144° 24' W Pennsylvanian(?) 3/30/79 86 USGS 78ARR33D,E,F 68° 29' N radiolarians Mississippian Jones, Murchey MR0526 144° 24' W 3/30/79 86 USGS 78ARR33 I-O 68° 29' N radiolarians Late(?) Mississippian to Early(?) Jones, Murchey MR0530 144° 24' W Pennsylvanian 3/30/79 87 USGS 78ARR34S 68° 29' N radiolarians Late Paleozoic Pennsylvanian(?) Jones, Murchey MR0532 144° 25' W 3/30/79 87 USGS 78ARR34R 68° 29' N radiolarians Late Paleozoic (Permian?) Jones, Murchey MR0531 144° 25' W (Pennsylvanian?) 3/30/79 87 USGS 78ARR34Q 68° 29' N radiolarians Late Paleozoic Jones, Murchey MR0533 144° 25' W 3/30/79 87 USGS 78ARR34H 68° 29' N radiolarians Mississippian(?) Jones, Murchey MR0534 144° 25' W 3/30/79 87 USGS 78ARR34BCD,E 68° 29' N radiolarians Late(?) Mississippian to Early(?) Jones, Murchey MR0528, FG 144° 25' W Pennsylvanian 3/30/79 0529 99 USGS 79ABe287 68° 24' N radiolarians Late Mississippian to Early Jones, Murchey MR1087 144° 43' W Pennsylvanian 3/31/81 125 60ABe561A 68° 19' N radiolarians Indeterminate Holdsworth 145° 13' W 9/17/78

28 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Pennsylvanian(?) and Mississippian Rocks, unnamed, phyllite, and chert (&Mp)—cont. 127 USGS 79ABe290A 68° 20' N radiolarians Late Mississippian to Early Jones, Murchey MR1090 145° 06'W Pennsylvanian 3/31/81 128 USGS 79ABe288 68° 22' N radiolarians Late Mississippian to Early Jones, Murchey, MR1088 144° 59'W Pennsylvanian(?) 3/31/81 Pennsylvanian and Mississippian Rocks, Lisburne Group (&MI), and Mississippian Rocks, Lisburne Group (MI) stratigraphic level of fossils in group uncertain 40 28755-PC 82ATr38 68° 45' N conodonts CAI 3.5 Latest Mississippian (Late Harris 11/22/82 146° 22' W Chester) 74 30190-PC 87Tr23 68° 31' N conodonts CAI 5 late Early to early Late Harris 6/20/88 145° 57' W Mississippian (Middle Osagean - Meramecian) 92 20385-PC 60ABe724 68° 28' N coral Mississippian(?) (or Devonian) Oliver 1/30/62 145° 16' W 95 60ABe722 68° 27' N corals Silurian to Permian Oliver 1/30/62 145° 23' W 101 78ARR13 68° 24' N radiolarians Mississippian Jones, Murchey 144° 32' W 3/30/79 102 78ARR12 68° 24' N foraminifers Mississippian (Late Osage to Mamet 11/1/87 E,F,G,H,I 144° 32' W (shallow water) Meramec) 102 78ARR12J 68° 24' N radiolarians Mississippian Jones, Murchey 144° 32' W 3/30/79 103 60ARR754 68° 26' N brachiopods Early Mississippian Dutro 1/25/62 144° 06' W 132 28751-PC 82ATr62F 68° 20' N conodonts CAI 5.5 Early Mississippian (Late Harris 11/22/82 144° 08' W Kinderhook through Osagean) 133 60ARR611 68° 18' N brachiopods Early Mississippian Dutro 1/25/62 144° 52' W corals Pennsylvanian and Mississippian Rocks, upper part of Lisburne Group (&Mlu), top beds 12 28754-PC 82ATr35 68° 50' N conodonts CAI 5- Latest Mississippian (Latest Harris 11/22/82 146° 25' W 5.5 Chester) 13 79ARR14F 68° 49' N brachiopods Middle(?) Pennsylvanian Dutro 6/18/90 146° 26' W 56 30196-PC 87Tr19 68° 39' N conodonts CAI 3 Early Pennsylvanian Harris 6/20/88 146° 05' W (Morrowan) 73 78ABe53A 68° 31' N brachiopods Middle(?) Pennsylvanian Dutro 6/18/90 145° 57' W 93 82ATr49A 68° 27' N conodonts CAI 5 Silurian to Permian Harris 12/10/82 145° 56' W 93 82ATr49A 68° 27' N foraminifers Early Late Mississippian Mamet 2/6/83 145° 56' W Pennsylvanian and Mississippian Rocks, top beds of undivided Lisburne Group (&Ml) 43 M-1071 72ARR253A 68° 48' N foraminifers Late Mississippian (Chester) Armstrong 3/73 145° 07' W 45 30189-PC 87Tr21 68° 43' N conodonts CAI 3- Very Late Mississippian (Late Harris 6/20/88 146° 07' W 3.5 Chester) 61 23582-PC 72ABe263D 68° 37' N brachiopods Middle(?) Pennsylvanian (Des Dutro 2/15/75 144° 34' W Moines) 61 M-1065 72ABe263D 68° 37' N foraminifers Late Missisisippian(?) Armstrong 3/73 144° 34' W (Chester?) 63 60ABe733 68° 37' N brachiopods Carboniferous Dutro 6/18/90 144° 28' W bryozoans 76 78ARR18A,B,C, 68° 29' N foraminifers Latest Mississippian to Earliest Mamet 11/1/87 D,E,F 145° 29' W Pennsylvanian (Namurian)

29 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Pennsylvanian and Mississippian Rocks, top beds of undivided Lisburne Group (&Ml)—cont. 77 22390-PC 66ABe316 68° 30' N brachiopods Mississippian(?) Grant 3/10/67 145° 27' W 77 29239-PC 83S792 68° 30' N conodonts CAI 5- Middle Pennsylvanian (Atokan) Harris 4/24/84 145° 27' W 5.5 123 66ABe296A 68° 21' N foraminifers Late Mississippian (Late Armstrong 5/8/73 145° 47' W Meramec to early Chester) (oral) 123 M1003 66ABe296A,B 68° 21' N corals Late Mississippian (Late Armstrong 11/7/66, 145° 47' W Meramec to early Chester) 5/8/73 (oral) Mississippian Rocks, lower part of Lisburne Group (Mll), lowest beds 5 M-1119 Armstrong 69R-4 68° 58' N corals Late Mississippian (Meramec) Armstrong 4/13/73 144° 52' W 6 M-1118 Armstrong 69R-3 68° 58' N corals Late Mississippian (Meramec) Armstrong 4/13/73 144° 53' W 11 79ABe251D 68° 51' N foraminifers Early Late Mississippian (Early Mamet 11/1/87 144° 42' W Meramec) Mississippian Rocks, Lowest beds of undivided Lisburne Group (&Ml) and (Ml) 50 M-1057 72ABe261D 68° 41' N foraminifers Late Mississippian (Meramec) Armstrong 12/1/72 144° 29' W 107 60ABe748 68° 19' N brachiopods Early Mississippian Dutro 12/11/61 146° 41' W 173 30191-PC 87Tr25A 68° 11' N conodonts CAI 5.5 Early Mississippian (Late Harris 6/20/88 145° 38' W Kinderhookian? through Osagean) 173 30192-PC 87Tr25B 68° 11' N conodonts CAI Late Early Mississippian (Early Harris 6/20/88 145° 38' W 5.5-6 3/4 of Osagean) Mississippian Rocks, Kayak Shale (Mk) 4 M-1121 69ADu32 68° 59' N foraminifers Late Mississippian(?) Armstrong 4/13/73 144° 51' W Meramec(?) 7 79ABe191 69° 00' N pelecypods Paleozoic Dutro 6/88 144° 14' W gastropods crinoids (fragments) 11 79ABe251C 68° 51' N conodonts CAI 5 Early Mississippian Harris 5/18/88 144° 42' W (Kinderhook) to Permian 48 79ABe134 68° 43' N coral Early Mississippian Dutro 6/15/90 144° 29' W 50 M-1057 72ABe261B 68° 41' N corals Late Mississippian (Meramec) Armstrong 12/1/72 144° 29' W 51 79ABe283 68° 41' N brachiopods Mississippian(?) Dutro 6/17/91 144° 28' W corals 51 79ABe283Y 68° 41' N foraminifers Not Middle Devonian Mamet 1/87 144° 28' W 60 60ABe729 68° 36' N corals Early Mississippian Dutro 1/25/62 145° 13' W 65 23577-PC 72ABe264 68° 36' N brachiopods Late(?) Mississippian Dutro 2/14/73 144° 34' W Meramec(?) 65 72ABe264 68° 36' N plants Indeterminate Mamay 12/22/72 144° 34' W 68 72ARR240 68° 33' N plants Indeterminate Mamay 12/22/72 144° 41' W 72 60ARR712 68° 33' N brachiopods Early Mississippian Dutro 12/11/61 144° 04' W

30 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Mississippian Rocks, Kayak Shale (Mk)—cont. 75 87Tr28B 68° 31' N conodonts CAI 5 Mississippian(?) (probably no Harris 6/20/88 145° 50' W younger than Middle Meramecian) 75 30195-PC 87Tr28C 68° 31' N conodonts CAI 5 Early Early Mississippian (upper Harris 6/20/88 145° 50' W Kinderhookian) 78 23580-PC 72ABe310B 68° 30' N brachiopods Early(?) Mississippian Dutro 2/14/73 145° 22' W (Osagean?) 88 79ABe207 68° 28' N conodonts CAI 5 Silurian to Permian Harris 5/18/88 144° 01' W 89 M-1014 66ABe319A 68° 29' N brachiopods Mississippian Armstrong 11/7/66 145° 26' W 89 66ABe319B 68° 29' N bryozoans Indeterminate Armstrong 11/7/66 145° 26' W 89 23578-PC 72ABe308 68° 29' N brachiopods Early(?) Mississippian (Osage?) Dutro 2/14/73 145° 26' W 89 23579-PC 72ABe308B 68° 29' N brachiopods Early(?) Mississippian (Osage?) Dutro 2/14/73 145° 26' W 94 30193-PC 87Tr27C 68° 27' N conodonts CAI 5 Early Early Mississippian Harris 6/20/88 145° 55' W (Kinderhookian) 94 87Tr27D 68° 27' N conodonts CAI 5 Ordovician - Triassic Harris 6/20/88 145° 55' W 100 66ABe300C 68° 26' N brachiopods Early Mississippian Dutro 1/23/73 144° 38' W 100 66ABe300E 68° 26' N bryozoans Mississippian(?) Dutro 1/23/73 144° 38' W 110 79ABe143B 68° 17' N brachiopods Early Mississippian Dutro 6/15/90 146° 43' W bryozoans 134 60ARR611A 68° 18' N brachiopods Early Mississippian Dutro 1/25/62 144° 52' W crinoids 134 23581-PC 72ABe318A 68° 18' N brachiopods Early(?) Mississippian (Osage?) Dutro 2/14/73 144° 52' W 135 60ARR613 68° 17' N brachiopods Early Mississippian Dutro 1/25/62 144° 53' W corals trilobites 136 23576-PC 72ABe225 68° 18' N brachiopods Early(?) Mississippian (Osage?) Dutro 2/14/73 144° 10' W 154 M-1013 66ABe314 68° 14' N brachiopods Possibly Late Devonian or Early Armstrong 11/7/66 145° 43' W Mississippian; Early Dutro 9/6/74 Mississippian(?) 158 60ARR697 68° 15' N bryozoans Early Mississippian(?) Dutro 12/11/61 144° 46' W coral Mississippian Rocks, Kekiktuk Conglomerate (Mkt) 3 78ABe47B 68° 58' N plants Early Mississippian Mamay 3/21/79 145° 35' W Mississippian(?) and Devonian Rocks, Kanayut Conglomerate (MDk) and Kanayut Conglomerate undivided (MDku) 46 78ABe46A 68° 41' N plants Probably Devonian, possibly Mamay 3/21/79 145° 53' W Mississippian 84 72ABe254 68° 30' N plants Indeterminate Mamay 12/22/72 144° 30' W 105 60ABe688 68° 20' N brachiopods Late Devonian (Famennian?) Dutro 12/13/61 146° 54' W 137 60ARR635 68° 16' N plants Late Devonian Mamay 11/4/60 144° 08' W 156 60ABe620 68° 15' N brachiopods Late Devonian (Famennian?) Dutro 12/11/61 144° 52' W

31 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Mississippian(?) and Devonian Rocks, Kanayut Conglomerate (MDk) and Kanayut Conglomerate undivided (MDku)—cont. 157 6417-SD 60ABe619 68° 15' N corals Late Devonian (Frasnian?) Dutro, Oliver 144° 54' W brachiopods 12/12/61 Mississippian(?) and Devonian Rocks, Stuver Member and middle part of Kanayut Conglomerate (MDksm) 8 72ABe210 68° 51' N plants Indeterminate Mamay 12/22/72 145° 26' W 9 79ABe240A 68° 53' N plants Unidentifiable Mamay, Hueber 145° 09' W 1/19/83 Upper Devonian Rocks, quartzite unit of Kanayut Conglomerate (Dkq) 138 79ABe194B 68° 12' N brachiopods Late Devonian (Famennian) Dutro 6/88 146° 54' W 159 79ABe274 68° 13' N brachiopods Late Devonian? Dutro 9/1/79 145° 04' W 175 79ABe164A 68° 12' N brachiopods Late Devonian (Famennian?) Dutro 6/88 144° 53' W crinoids plant fragments fish fragments Upper Devonian Rocks, lower part of Kanayut Conglomerate (Dkl) 96 78ABe33E 68° 26' N plants Devonian Mamay 3/21/79 145° 03' W 96 78ABe33G 68° 26' N plants Devonian Mamay 3/21/79 145° 03' W Upper Devonian Rocks, Noatak Formation (Dn) 97 79ABe213 68° 27' N conodonts CAI 4-5 Middle Devonian to Early Harris 5/18/88 144° 52' W Mississippian 97 79ABe213A 68° 27' N conodonts CAI 4-5 Late Devonian (Famennian?) Harris 5/18/88 144° 52' W 97 79ABe213 68° 27' N brachiopods Late Devonian (Famennian?) Dutro 6/90 144° 52' W pelecypods 160 79ABe163 68° 13' N brachiopods Late Devonian (Famennian) Dutro 8/10/79 144° 56' W 185 72ABe213A 68° 10' N plants Indeterminate Mamay 12/22/72 144° 21' W 185 72ABe213B 68° 10' N plants Indeterminate Mamay 12/22/72 144° 21' W Upper Devonian Rocks, wacke member of Beaucoup Formation (Dbw) 53 79ABe279B 68° 40' N brachiopods Late Devonian (Frasnian) Dutro 6/90 144° 02' W crinoids 98 60ARR741 68° 25' N corals Middle or Late Devonian(?) Oliver 2/27/61 144° 54' W brachiopods (Frasnian?) 106 76ABe423 68° 19' N brachiopods Late Devonian (Frasnian) Oliver 2/27/61, 147° 00' W corals Dutro 6/90 108 78ABe23A 68° 17' N brachiopods Late Devonian (Frasnian) Dutro 6/90 78ABe23 146° 48' W 108 78ABe23C 68° 17' N brachiopods Late Devonian (Frasnian) Dutro 6/90 146° 48' W corals 113 79ABe139A 68° 15' N brachiopods Late Devonian (Frasnian) Dutro 6/18/90 146° 46' W corals gastropods 148 11130-SD 84TAH22B 68° 15' N conodonts CAI 5- Late Devonian Harris 4/18/85, 6/88 146° 06' W 5.5 148 11129-SD 84TAH22 68° 15' N conodonts CAI 5 Late Devonian Harris 4/18/85, 6/88 146° 06' W

32 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Upper Devonian Rocks, wacke member of Beaucoup Formation (Dbw)—cont. 149 78ABe24 68° 14' N brachiopods Late Devonian (Frasnian) Dutro 6/90 145° 55' W corals 162 9075-SD 72ABe228A 68° 10' N brachiopods Middle to Late Devonian Dutro 6/87 146° 20' W 164 60ARR784 68° 10' N brachiopods Late Devonian (Frasnian) Dutro 12/11/61 146° 13' W 169 60ABe546 68° 11' N brachiopods Late Devonian (Frasnian?) Dutro 12/12/61 145° 54' W 170 60ABe547 68° 12' N brachiopods Late Devonian (Frasnian?) Dutro 12/11/61 145° 53' W 171 60ABe548 68° 12' N brachiopods Late Devonian (Frasnian?) Dutro 12/12/61 145° 53' W 172 60ABe549A 68° 12' N brachiopods Late Devonian (Frasnian) Dutro 12/11/61 145° 52' W 174 60ARR618 68° 11' N brachiopods Late Devonian (Frasnian?) Dutro 12/11/61 145° 13' W gastropods 179 60ABk201 68° 10' N brachiopods(?) Indeterminate Dutro 12/11/61 145° 53' W 180 6427-SD 60ABk202 68° 09' N corals Late Devonian (Frasnian) Dutro, Oliver 145° 52' W brachiopods 12/11/61 181 60ABe745 68° 09' N brachiopods Devonian(?) Dutro 12/13/61 145° 41' W 184 11122-SD 84JFY66 68° 09' N conodonts CAI 5 Devonian Harris 4/18/85, 6/88 145° 00' W 198 60ARR649 68° 05' N brachiopods Late Devonian (Frasnian) Dutro 6/87 144° 37' W Upper Devonian Rocks, Hunt Fork Shale (Dhf) 67 9064-SD 72ARR246 AX 68° 36' N conodonts CAI 4- Middle to Late Devonian Harris 5/18/88 9065-SD 246 AY 144° 17' W 4.5 67 9077-SD 72ARR246 68° 36' N brachiopods Late Devonian (Frasnian) Dutro 6/90 144° 17' W 69 72ABe258F 68° 33' N plants Indeterminate Mamay 12/22/72 144° 17' W 71 60ABe735 68° 33' N brachiopods Late Devonian(?) Dutro 12/13/61 (reported as 144° 14' W 734) 96 78ABe33A 68° 25' N brachiopods Late Devonian (Frasnian?) Dutro 6/88 145° 03' W gastropods Upper Devonian Rocks, limestone member of Hunt Fork Shale (Dhl) 66 9080-SD 72ARR248 68° 35' N brachiopods Late Devonian (Frasnian) Dutro 6/87 144° 22' W corals 70 9073-SD 72ABe258B 68° 34' N brachiopods Late Devonian (Frasnian?) Dutro 6/10/91 144° 16' W 70 9079-SD 72ABe258D 68° 34' N brachiopods Late(?) Devonian (Frasnian?) Dutro 6/10/91 144° 16' W 176 79ABe165B 68 12'N corals Late(?) Devonian Frasnian(?) Dutro 6/90 144 47'W Upper Devonian Rocks, unnamed tuff (Dvt) 196 60ARR642 68° 05' N brachiopods Late Devonian(?) Dutro 12/13/61 144° 47' W 196 60ARR642Z 68° 05' N brachiopods Late Devonian (Frasnian)(?) Dutro 12/13/61 144° 47' W

33 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Upper Devonian Rocks, unnamed tuff (Dvt)—cont. 197 11124-SD 84JFY73 68° 05' N conodonts CAI 5- Late Devonian (Frasnian) Harris 4/18/85, 6/88 144° 43' W 5.5 (loc?) 205 11123-SD 84JFY68A 68° 01' N conodonts CAI 5- Late Devonian Harris 5/18/88 145° 20' W 5.5 (loc?) 207 10864-SD 83S746B 68° 01' N conodonts CAI 5 Late Devonian (Frasnian) Harris 4/24/84 144° 43' W (loc?) Upper Devonian(?) Rocks, unnamed wacke (Dw) 114 60ABe672 68° 20' N plants Unidentifiable Mamay 11/4/60 146° 19' W 119 72ABe302 68° 21' N plants Indeterminate Mamay 12/22/72 146° 08' W 120 72ABe303 68° 20' N plants Indeterminate Mamay 12/22/72 146° 06' W 121 78ARR3A 68° 20' N spore (one) Devonian(?) Haga 9/12/80 146° 06' W 129 78ARR3B 68° 20' N plants Unidentifiable Mamay 3/21/79 144° 48' W 129 78ARR3C 68° 20' N spores (non- Late(?) Devonian Haga 3/6/80 144° 48' W marine) 130 78ARR4 68° 20' N spore (one) (non- Indeterminate Haga 3/6/80 144° 47' W marine) 131 72ABe324 68° 21' N plants Indeterminate Mamay 12/22/72 144° 33' W 155 79ABe162A 68° 13' N spores Indeterminate Haga 9/12/80 145° 35' W Upper Devonian Rocks, Beaucoup Formation, brown calcareous siltstone member (Db) 141 79ARR11A 68° 13' N brachiopods Late Devonian (Frasnian) Dutro 6/15/90 146° 21' W corals Upper Devonian Rocks, Beaucoup Formation, conglomerate member (Dbc) 143 60ARR786 68° 12' N gastropods Devonian(?) Dutro 12/11/61 146° 14' W 163 9076-SD 72ABe230H 68° 09' N echinoderm debris Indeterminate Dutro 3/7/73 146° 25' W and fish(?) remains 191 11117-SD 84JFY45 68° 06' N conodonts CAI 5- Silurian through Middle Harris 4/18/85, 6/88 146° 26' W 5.5 (in clast in Devonian conglomerate) 192 11119-SD 84JFY52 68° 05' N conodonts CAI 5 Late Devonian (Famennian) Harris 4/18/85, 6/88 146° 26' W Upper Devonian Rocks, Beaucoup Formation, limestone member (Dbl) 126 11861-SD 87Tr29 68° 21' N conodonts CAI 5 latest Middle to early Late Harris 2/5/88 145° 10' W Devonian 140 79ARR13 68° 13' N coral Late(?) Devonian (Frasnian?) Dutro 6/91 146° 21' W 140 11115-SD 84JFY19 68° 13' N conodonts CAI 5 Late Devonian (Frasnian) Harris 4/18/85, 6/88 146° 21' W 142 6430-SD 60ARR785 68° 11' N corals Middle or early Late Devonian Oliver 2/16/61 146° 15' W Oliver 1975 144 78ABe25A 68° 11' N brachiopods Late Devonian (Frasnian?) Dutro 6/88 146° 08' W corals

34 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Upper Devonian Rocks, Beaucoup Formation, limestone member (Dbl)—cont. 144 78ABe25A 68° 11' N conodonts CAI 5 Middle Devonian to Early Harris 3/27/79 146° 08' W Mississippian 145 11006-SD 84JFY32 68° 11' N conodonts CAI 5 Late Devonian Harris 10/10/84 146° 07' W 146 84TAH2 68° 11' N conodonts CAI 5 Ordovician to Triassic Harris 5/18/88 146° 05' W 147 8792-SD 66ABe312D 68° 12' N corals Late Devonian (Frasnian) Oliver 2/15/72 145° 58' W Oliver 1975 147 8791-SD 66ABe312B 68° 12' N corals Late Devonian (Frasnian) Oliver 2/15/72 145° 58' W brachiopods Oliver 1975 150 6408-SD 60ARR584 68° 14' N corals Late Devonian (Frasnian?) Oliver 2/10/61 145° 53' W brachiopods Oliver 1975 151 79ABe161A 68° 13' N corals Late Devonian (Frasnian) Dutro 6/15/90 145° 50' W 152 6414-SD 60ABe555A 68° 13' N corals Late Devonian (Frasnian) Oliver 2/10/61 145° 50' W Oliver 1975 152 6415-SD 60ABe555B 68° 13' N corals Late Devonian (Frasnian) Oliver 2/10/61 145° 50' W Oliver 1975 152 6416-SD 60ABe555C 68° 13' N corals Late Devonian (Frasnian) Oliver 2/10/61 145° 50' W Oliver 1975 152 6407-SD 60ABe555D 68° 13' N corals Late Devonian (Frasnian) Oliver 1975 145° 50' W brachiopods 152 8168-SD 66ABe313 68° 13' N brachiopods Late(?) Devonian (Frasnian?) Dutro 5/29/68 145° 50' W 153 6426-SD 60ABe557 68° 13' N corals Late Devonian (Frasnian) Oliver 1975 145° 46' W 161 11128-SD 84JFY95 68° 11' N conodonts CAI 5 Late Devonian 146° 25' W 166 6422-SD 60ARR787 68° 11' N corals Late Devonian (Frasnian) Oliver 12/16/61 cobbles in 146° 08' W pelecypods Oliver 1975 stream 167 8911-SD 25576-11 68° 11' N corals Late Devonian (Frasnian) Oliver 1975 (Standard Oil of 145° 58' W CA) 168 8910-SD 25576-7 68° 11' N corals Late Devonian (Frasnian) Oliver 1975 (Standard Oil of 145° 57' W CA) 176 6413-SD 60ABe549F 68° 12' N corals Late Devonian (Frasnian) Oliver 1975 145° 52' W gastropods 177 6425-SD 60ABk203 68° 09' N corals Late Devonian (Frasnian) Oliver 1975 145° 55' W 178 72ABe233 68° 09' N corals No report 145° 53' W 194 5727-SD 60ARR782 68° 05' N corals Devonian Dutro, Yochelson 146° 18' W gastropods 12/11/61 Oliver 1975 195 60ARR769 68° 06' N brachiopods Middle(?) or early Late(?) Dutro 5/12/65 145° 46' W Devonian 202 6440-SD 60ARR719 68° 01' N corals Devonian Oliver 1975 146° 15' W Middle Devonian(?) Rocks, unnamed shale (Ds) 10 79ABe249A 68° 53' N big pelecypods Devonian(?) Pojeta 6/87 145° 09' W

35 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Middle Devonian Rocks, unnamed limestone, shale, and conglomerate (Dls) 49 79ABe281B 68° 42' N brachiopods Middle(?) Devonian Dutro 6/17/91 144° 10' W pelecypods 49 79ABe281C 68° 42' N brachiopods Devonian Dutro 6/88 144° 10' W trilobite 52 79ABe132A 68° 41' N brachiopods Middle Devonian Dutro 6/15/90 144° 15' W trilobite sponge spicules 52 79ABe132B 68° 41' N conodonts CAI 5 Middle or Late Devonian Harris 5/18/88 144° 15' W 52 79ABe132D 68° 41' N bryozoans Middle Devonian Dutro 6/15/90 144° 15' W tentaculitids 54 79ABe284C 68° 39' N corals Late(?) Devonian (Frasnian?) Oliver 3/25/91 144° 25' W 55 60ABe580 68 40' N pelecypods Indeterminate Dutro 12/11/61 144 09' W 64 72ARR245 68° 37' N gastropods Middle Devonian(?) Yochelson 6/88 144° 24' W Middle Devonian and Silurian Rocks, unnamed limestone (DSl) 186 8913-SD 256009-9 68° 09' N corals Late(?) Silurian (Ludlovian?) Oliver 1975 (Standard Oil of 144° 18' W CA) 186 6434-SD 60ARR660 68° 09' N corals Middle or Late Devonian (Late? Oliver 1/30/62 144° 18' W Devonian) Oliver 1975 187 11125-SD 84JFY86 68° 09' N conodonts CAI 5 Middle Devonian Harris 5/18/88 144° 20' W 188 9081-SD 72ABe215A 68° 09' N brachiopods Late Devonian (Frasnian?) Dutro 6/88 144° 19' W 188 72ABe215B 68° 09' N corals Middle(?) Devonian Dutro, Oliver 6/88 144° 19' W 188 72ABe215C 68° 09' N corals Middle(?) Devonian Dutro, Oliver 6/88 144° 19' W 188 72ABe215D 68° 09' N corals Middle(?) Devonian Dutro, Oliver 6/88 144° 19' W 188 72ABe215E 68° 09' N corals Middle(?) Devonian Dutro, Oliver 6/88 144° 19' W 188 72ABe215F 68° 09' N corals Middle(?) Devonian Dutro, Oliver 6/88 144° 19' W 189 60ARR659 68° 09' N trilobites Devonian(?) Dutro 5/12/65 144° 18' W Devonian through Ordovician Rocks, Skajit Limestone (DOs) 139 84JFY96A 68° 13' N conodonts CAI 5 Ordovician through Permian Harris 6/88 146° 28' W 165 84JFY3168° 10' N conodonts CAI 5 Middle Silurian through Harris 6/88 146° 10' W Mississippian 190 84JFY4668° 06' N conodonts CAI 5 Middle Ordovician through Harris 6/88 146° 25' W Middle Devonian 193 84JFY4268° 05' N conodonts CAI 5 Early Ordovician through Harris 6/88 146° 29' W Devonian 199 84JFY5 68° 02' N conodonts CAI 5- late Late Ordovician Harris 11/17/88 146° 14' W 5.5 200 11114-SD 84JFY13 68° 01' N conodonts CAI 5 Silurian through Early Devonian Harris 5/18/88 146° 12' W (probably Silurian) 201 7011-SD 63ARR210 68° 01' N corals Late Ordovician to early Late Oliver 9/27/63 146° 14' W Devonian

36 Table 1. Fossil Collections from the Arctic Quadrangle, Alaska—Continued

Map USGS Locality Field Sample No. Latitude Fossils Age Identified by No.* No.** Longitude Ordovician and Cambrian(?) Rocks, unnamed chert and phyllite (O_c) 1 83BR742 (MC) 70° 00' N graptolites Middle Ordovician(?) Carter 6/18/84 collected by 145° 30' W Moore, Churkin, geologists of 1984 ARCO Alaska 2 83BR744 (MC) 69° 59' N graptolites Middle Ordovician(?) Carter 6/18/84 collected by 145° 30' W Moore, Churkin, geologists of 1984 ARCO Alaska

37 Table 1A. Index map numbers and symbols of the geologic map units at each fossil collection site.

Map No. Geologic Map Unit Map No. Geologic Map Unit Map No. Geologic Map Unit Map No. Geologic Map Unit

1 O_c 53 Dbw 105 MDku 157 MDku 2 O_c 54 Dls 106 Dbw 158 Mk 3 Mkt 55 Dls 107 Ml (base) 159 Dkq 4 Mk 56 &Mlu (top) 108 Dbw 160 Dn 5 Mll (base) 57 ^Pss 109 P&i; &Ma 161 Dbl

6 Mll (base) 58 ^Pss 110 Mk 162 Dbw 7 Mk 59 ^Pss 111 &Ma 163 Dbc 8 MDksm 60 Mk 112 &Ma 164 Dbw 9 MDksm 61 &MI (top) 113 Dbw 165 DOs 10 Ds 62 ^Pss 114 Dw 166 Dbl

11 Mll (base); Mk 63 &Ml (top) 115 ^Pss 167 Dbl 12 &Mlu (top) 64 Dls 116 ^o 168 Dbl 13 &Mlu (top) 65 Mk 117 ^o 169 Dbw 14 ^Ps 66 Dhl 118 ^Ms 170 Dbw 15 ^s 67 Dhf 119 Dw 171 Dbw

16 ^s 68 Mk 120 Dw 172 Dbw; Dbl 17 ^s 69 Dhf 121 Dw 173 &Ml (base) 18 ^s 70 Dhl 122 Pe 174 Dbw 19 ^s 71 Dhf 123 &Ml (top) 175 Dkq 20 ^Ps 72 Mk 124 Pe 176 Dhl

21 ^o 73 &Mlu (top) 125 &Mp 177 Dbl 22 ^s ; ^Ps 74 &Ml 126 Dbl 178 Dbl 23 Ki 75 Mk 127 &Mp 179 Dbw 24 Ki 76 &Ml (top) 128 ^Ms 180 Dbw 25 ^Ps 77 &Ml (top) 129 Dw 181 Dbw

26 ^s ; ^Ps 78 Mk 130 Dw 182 Qu 27 ^o 79 Pe 131 Dw 183 Qu 28 ^Pe; ^Mi 80 Pe 132 Ml 184 Dbw 29 ^Pv 81 ^Ms 133 Ml 185 Dn 30 Kk 82 ^Ms 134 Mk 186 DSl

31 ^Ps 83 ^Pss 135 Mk 187 DSl 32 ^Ps 84 MDk 136 Mk 188 DSl 33 ^o 85 &Mp 137 MDku 189 DSI 34 ^e 86 &Mp 138 Dkq 190 DOs 35 ^Mi 87 &Mp 139 DOs 191 Dbc

36 ^Mi 88 Mk 140 Dbl 192 Dbc 37 &Ma 89 Mk 141 Db 193 DOs 38 ^Pe 90 ^Pss 142 Dbl 194 Dbl 39 Kk 91 &Mk 143 Dbc 195 Dbl 40 &Ml 92 &Ml 144 Dbl 196 Dvt

41 ^Pss 93 &Mlu (top) 145 Dbl 197 Dvt 42 ^Pss 94 Mk 146 Dbl 198 Dbw 43 ^Pss; &PMl (top) 95 &Ml 147 Dbl 199 DOs 44 ^Pss 96 Dkl; Dhf 148 Dbw 200 DOs 45 &Ml (top) 97 Dn 149 Dbw 201 DOs

46 MDk 98 Dbw 150 Dbl 202 Dbl 47 ^Pss 99 &Mp 151 Dbl 203 ^Ms 48 Mk 100 Mk 152 Dbl 204 ^Ms 49 Dls 101 &Ml 153 Dbl 205 Dvt 50 &Ml (base); Mk 102 &Ml 154 Mk 206 ^Ms

51 Mk 103 &Ml 155 Dw 207 Dvt 52 Dls 104 ^Pss 156 MDku

38