Stratigraphy of the Wind River Formation in South-Central Wind River Basin, Wyoming GEOLOGICAL SURVEY PROFESSIONAL PAPER 594-A Prepared in cooperation with the U.S. Atomic Energy Commission STRATIGRAPHY OF THE WIND RIVER FORMATION IN SOUTH-CENTRAL WIND RIVER BASIN North end Rattlesnake Range South end Bighorn Mts - \ I Part of south-central Wind River Basin. View northeastward from a point about one-half mile north of Coyote Springs. Puddle Springs Arkose Member of the Wind River Formation underlies most of area of photograph. Lines trace outcrop of Dry Coyote Conglomerate Bed (top and base not shown) of the Puddle Springs Arkose Member. Kc, Cody Shale. Aerial photograph courtesy of Page J enkins. Stratigraphy of the Wind River Formation in South-Central Wind River Basin, Wyoming By PAUL E. SOISTER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 594-A Prepared in cooperation with the U.S. Atomic Energy Commission A detailed study of the physical stratigraphy of the uraniu1n-bearing formation in and near the important Gas Hills uranium district of central Wyoming UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1968 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 CONTENTS Page Abstract------------------------------------------------------------------------------------------------------ A1 Introduction__________________________________________________________________________________________________ 2 Geologic setting_______________________________________________________________________________________________ 2 VVind River Formation_________________________________________________________________________________________ 7 History of stratigraphic terms_______________________________________________________________________________ 7 Paleontology and stratigraphic position_______________________________________________________________________ 9 General lithology and thickness______________________________________________________________________________ 10 Occurrence and facies relations_ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ __ _ __ _ _ __ __ _ _ _ __ __ _ _ __ __ __ _ _ _ _ __ _ _ __ _ _ _ _ _ _ _ _ _ __ __ __ _ _ _ _ _ __ __ _ 11 Correlations----------------------------------------------------------------------------------------------- 14 Lithologic units____________________________________________________________________________________________ 15 Lower fine-grained member_ _ _ __ _ _ _ _ __ __ __ _ __ _ __ _ __ __ _ __ __ _ _ _ _ _ _ _ __ _ _ __ __ _ _ _ _ _ _ _ _ __ __ _ _ _ _ _ _ _ _ _ __ __ _ _ _ _ __ 15 Conglomerate_____________________________________________________________________________________ 16 Sandstone________________________________________________________________________________________ 17 Siltstone__________________________________________________________________________________________ 17 Claystone_________________________________________________________________________________________ 18 Carbonaceousbeds_________________________________________________________________________________ 18 Puddle Springs Arkose Member_________________________________________________________________________ 20 General description and occurreD ce _ _ _ _ _ __ _ __ _ _ __ _ __ _ _ __ _ _ __ __ _ _ _ __ __ __ _ _ __ _ _ _ __ _ __ __ __ _ _ __ _ _ _ _ _ _ _ _ _ _ 20 Rock types and units ____________ ~_________________________________________________________________ 26 Channelsandstonebeds________________________________________________________________________ 26 Landslide debris from the Mowry Shale__________________________________________________________ 26 Carbonaceous beds and carbonized and silicified wood______________________________________________ 30 East Canyon Conglomerate Bed_________________________________________________________________ 32 I>ry Coyote Conglomerate Bed__________________________________________________________________ 33 Muskrat Conglomerate Bed_____________________________________________________________________ 36 Other conglomerate beds_ _ _ _ _ _ __ __ __ __ __ _ _ __ _ _ __ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ __ __ _ _ _ _ _ __ __ __ __ _ _ 3 7 Upper transition zone__________________________________________________________________________________ 38 Source of sediments________________________________________________________________________________________ 39 I>epositional environment___________________________________________________________________________________ 40 PaleogeographY---------------------------------------------------------------------------------------- 40 Paleoclimate__________________________________________________________________________________________ 42 I>eposition of sediments__ _ _ _ _ _ __ _ _ _ _ _ __ __ _ __ _ __ _ __ _ __ __ _ _ _ __ _ _ __ _ _ _ __ __ __ __ _ _ _ _ __ _ _ _ _ _ _ _ __ __ __ _ _ _ _ _ _ __ _ 45 Stratigraphic position of uranium deposits____________________________________________________________________ 4 7 References cited___ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ __ __ _ _ __ _ _ __ __ __ _ _ __ _ _ _ __ _ __ __ __ __ __ __ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ __ __ _ _ _ _ _ __ _ _ __ _ _ _ _ _ 48 ILLUSTRATIONS [Plates 1-5 are in pocket] PLATE 1. Geologic map of south-central VVind River Basin. 2-4. Stratigraphic sections of Wind River Formation: 2. Areas A and B. 3. Areas C and I>. 4. Areas E, F, and G. 5. Geologic map showing outcrop of I>ry Coyote and Muskrat Conglomerate Beds. FRONTISPIECE. Part of south-central Wind River Basin. View northeastward from a point about one-half mile north of Coyote Springs. Page FIGURE 1. Index map of central VV yoming_ __ _ __ __ __ _ __ _ __ _ __ _ __ _ __ __ _ _ _ _ _ _ _ __ __ _ _ _ _ __ _ _ __ _ __ _ _ __ _ _ _ _ __ _ _ _ _ _ __ _ _ _ _ A3 2. Map of the south-central part of the VVind River Basin showing location of measured sections, facies and other boundaries, and depositional edge of the Wind River Formation_______________________________________ 4 v VI CONTENTS Page FIGURE 3. Photograph showing exhumed ridges and valleys of breached Dutton Basin anticline and large open-pit uranium mines in the Puddle Springs Arkose Member________________________________________________________ A6 4. Photograph of Beaver Divide escarpment southeast of Coyote Springs______________________________________ 7 5. Diagrammatic section of Wind River Formation in south-central and central Wind River Basin_______________ 8 6. Isopach map showing original thickness of Wind River Formation and physiographic features of pre-Tertiary rocks that affected deposition of the sediments______________________________________________________ 11 7. Diagrammatic stratigraphic section of Wind River Formation near south-central edge of Wind River Basin_____ 12 8. Photographs showing lower fine-grained member of the Wind River Formation______________________________ 16 9. Map of an area south of Coyote Springs showing variation in thickness of a carbonaceous shale penetrated by drillholes--------------------------------------------------------------------------------------- 19 10. Photographs of the coal and carbonaceous shale of the central carbonaceous zone at a Lucky Me open-pit uranium Inine___________________________________________________________________________________________ 21 11. Map showing present extent of central carbonaceous zone of lower fine-grained member of Wind River Formation and approximate position and geology of highlands during its deposition_________________________________ 22 12. Diagrammatic section of flat, tabular body containing limonite, Inanganese, and uranium in sandstone above Dry Coyote Conglomerate Bed____________________________________________________________________ 25 13. Geologic map and cross sections showing lower Eocene landslide debris from the Mowry Shale west of Coyote Springs_________________________________________________________________________________________ 29 14. Photographs of lower Eocene landslide debris from the Mowry Shale______________________________________ 30 15. Paleogeographic map showing approximate limits of East Canyon Conglomerate Bed and position of highlands during deposition of the sediments_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 32 16-19. Photographs showing: 16. Dry Coyote Conglomerate Bed exposed in a uranium prospect pit__________________________________ 34 17. Dry Coyote Conglomerate Bed in W~ sec. 32, T. 33 N., R. 90 W__________________________________ 35 18. Conglomerate and sandstone of the Puddle Springs Arkose Member exposed in an open-pit uranium mine__ 37 19. Marker beds in lower part of Wagon Bed Formation and part of upper transition zone of the Wind River Formation_______________________________________________________________________________ 38 TABLE Page TABLE 1. Rocks overlapped by Wind River Formation in areas shown in figure 2____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ A5 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY STRATIGRAPHY OF THE WIND RIVER FORMATION IN SOUTH-CENTRAL WIND RIVER BASIN WYOMING By PAuL E. SoisTER ABS'l'RACT and silicified wood are common in parts of the arkose. Cementing or interstitial materials include clay, gypsum, limonite, calcite, The area of this report is the t:outh-central part of the Wind jarosite, pyrite,