Geology of the Circle Cliffs Area, Garfield and Kane Counties, Utah By E. S. DAVIDSON GEOLOGICAL SURVEY BULLETIN 1229 Prepared on behalf of the U.S. Atomic Energy Commission Stratigraphy, structure, and economic geology of an area at the west edge of the Colorado Plateau UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. GS 67-266 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Abstract _____________________________________________________ 1 Introduction._____________________________________________________ 2 Location and extent of area.._________._________...____.___-_.__ 2 Geography and physiography.__________________________________ 3 Previous work_________________________________________________ 4 Purpose and scope...__________________________________________ 5 Field methods_______________________________________________ 5 Acknowledgments. ____________________________________________ 6 Stratigraphy-_____________________________________________________ 6 Permian System.._____________________________________________ 10 Cutler Formation____-._________..____.___..___._.___..._ 10 Kaibab Limestone._-_____--______-__-_____--_-_-____--_-_- 13 Permian-Triassic unconformity.___......_____._._.._._._._._.___ 14 . Triassic System.______________________________________________ 15 Moenkopi Formation._____________________________________ 15 Basal unit____________________________________________ 15 Sinbad Limestone Member.____________________________ 17 Lower ledge-forming unit..___--__-__________-___-_-_--- 19 Slope-forming unit___________________________________ 22 Upper ledge-forming unit___-___________--___-__----__ 22 Chinle Formation _______________________________________ 24 Mottled-siltstone unit..__________.___-_______-_.__----- 24 Shinarump Member____________________________________ 28 Alteration associated with the Shinarump Member_________ 31 Monitor Butte Member._______________________________ 32 Petrified Forest Member.___-________________-__-_----. 33 Owl Rock Member.___________________________________ 34 Church Rock Member.________________________________ 34 Triassic and Jurassic Systems._-_______-____-______-_-___-_----- 35 Glen Canyon Group.______________________________________ 35 Wingate Sandstone._________-___--__-______-_____---__ 35 Kayenta Formation__________________________________ 36 Navajo Sandstone._______________-__-________-_--_---- 37 Jurassic System.______________________________________________ 38 San Rafael Group_-_--_--_-__-_-_-___--_-----_--__-------- 38 Carmel Formation.____________________________________ 40 Entrada Sandstone____________________________________ 41 Curtis(?) Formation._______________-___-_-_-___-_----- 44 Summerville Formation,____-_-_____-_-_-_---_-------.- 44 Morrison Formation_____________________-_____--_--__-_- _. 45 Salt Wash Sandstone Member________-_-_--_--__----_-.__ 45 Brushy Basin Shale Member.__.____.____-_-_-___-_---_- 46 in IV CONTENTS Stratigraphy Continued Page Cretaceous System,____________________________________________ 47 Dakota Sandstone._-__---__-__-_____--_-__________--______ 48 Mancos Shale.___-_______--__---_--____-__________________ 50 Tununk Shale Member______-_-___-_-__________________ 50 Ferron Sandstone Member____________________________ 51 Blue Gate Shale Member.______________________________ 51 Emery Sandstone Member_________.____________________ 51 Masuk Member._--_--_-_---_-_-_-_-_--_______________ 52 Mesaverde Formation..___-___---_____-_-___-_-___-________ 52 Tertiary and Quaternary Systems___--------_------__-----___-__ 53 Bouldery deposits._______-_---_----_-_---_-__-____.._______ 53 Pediment deposits and pediments...._-___-_-_-___-_______-__ 53 Terrace gravel.____________-__--_-_--__------__-_--_--_-__ 54 Landslide deposits._____---_--__-_-_-_-_-----___-_-___-_-__ 55 Older alluvium in Hall Creek.___________---____-__-___-____ 58 Fan deposits._____________________________________________ 58 Talus._--------------_--------------------------.-------_ 58 Stream alluvium_______________---__-_-_-_-__--_-________ 58 Windblown-sand deposits..________-_--__-___-___-_-________ 59 Structure. ________________________________________________________ 59 Method of representing structure.__-___-___-___-____----------__ 60 Circle Cliffs anticline_________-__-_--__-_-___-_______-__________ 61 Henry Mountains syncline_______-_-_-_-_---___-_--_____________ 61 Faults---.------.----------.--_-----------_-_-_-_-_-__--_-__ 61 Joints._______________________________________________________ 62 Periods of deformation.________________________________________ 62 Uranium deposits__--_-__-_____--_-_---_-___--____-______________ 65 General character and distribution.__---_-----_-_-_____._________ 65 Mineralogy of deposits._'__-_____-_-_-_--_------_-__--_-_------- 68 Relation of asphalt to uranium deposits._________.___--_-_---____ 69 Correlation of tectonic structure and uranium deposits_____________ 69 Criteria and origin of uranium deposits.._____________--_---_-_-_- 70 Future of the area.___________________-_-______-___--_--_--_--- 71 Principal prospects._______________________________________________ 71 Buff and Red Cliff prospects..__________________________________ 72 Cool prospect___________________ ______________________________ 73 Bart, Centipede, and Midas prospects..__________________________ 73 Horsehead prospect.-__--_-.---.--___---______-_.___-_-______-_ 74 Blue Goose prospect.__________________________________________ 76 Horse Canyon prospect____________-_____________-______________ 76 Stud Horse prospect.__________________________________________ 77 Glen Rae prospect.____________________________________________ 78 Blue Bird prospect_______--__-____-_-__-__-_--__-----------_--_ 78 Lone B prospect________-__--_____-___-_-_--_------___--_---- 78 Black Widow prospect.___-_-_-_-_-_-__--__-___--__________--__ 79 Mesa prospect________________________________________________ 80 Yellow Jacket prospect.._______________________________________ 80 Hotshot prospect._____________________________________________ 83 Sneaky-Silver Falls prospect.___________________________________ 84 Duke prospect._______________________________________________ 84 Sun Dog prospect.____------_-__------------------------------ 85 CONTENTS V Principal prospects Continued Betty Jack prospect.__________________________________________ 85 Rainy Day mine and Rocky Mountain Co. prospects ______________ 85 Copperhead prospect___--_-____---__-_-__--_____-_-____._.__. 86 Hope prospect._______________________________________________ 87 Zelda prospect.___--_---_-_-__-____---_____-______-_-____-_-__ 87 Three Pardners prospect__----_-_-__----_____--_____-___-______. 87 Dodie prospect._______________________________________________ 88 Red Head prospect.__-_-_-----__------_---__-__-______-___-_-_ 88 Moqui prospect.______________________________________________ 88 Olympic prospect...-__----_--___--------_--_--__--_______-____ 89 Dream prospect.______________________________________________ 89 Solitude prospect._____________________________________________ 91 Metalliferous deposits other than uranium.___________________________ 91 Manganese ______._-_______-__-__----_-__-_-__________________ 91 Selenium.____________________________________________________ 92 Titanium..._.._._.____._ -___-_-._.__-_-_-_______-. _________ 92 Stratigraphic sections._____________________________________________ 93 Literature cited.__________________________________________________ 131 ____-_--_--_------_----------_------------_-------------_- 137 ILLUSTRATIONS Page PLATE 1. Geologic map of the Circle Cliffs area,..____________ In pocket 2. Tectonic map of part of the Circle Cliffs area._______ In pocket FIGURE 1. Indexed relief map showing location of the Circle Cliffs area____________________________________________ 2 2. Photographs showing Triassic rocks in southeast Circle Cliffs...__________________________________________ 16 3. Map showing distribution of Sinbad Limestone Member of the Moenkopi Formation.....-.-.________________ 18 4. Map showing distribution of asphalt in the Moenkopi Formation._______________________________________ 20 5. Photographs showing upper ledge-forming unit of the Moenkopi Formation_____________________________ 23 6. Map showing distribution of the mottled-siltstone unit of the Chinle Formation.___________________________ 25 7-13. Photographs showing: 7. Mottled-siltsone unit of the Chinle Formation.... 26 8. Shinarump Member of the Chinle Formation.____ 28 9. Hall Creek Valley near Burr Trail-_____________ 39 10. Upper and lower contacts of the Entrada Sand­ stone. -_-_-_-...---.------__..-_-_--.------ 42 11. Dakota Sandstone.------------.--------------- 49 12. Terrace gravel--------.-------.--------------- 55 13. Landslide remnants-___________________________ 56 14. Map showing uranium prospects and distribution and channel pattern of the Shinarump Member.__________ 66 15. Map of Centipede prospect.__________________________ 75 VI CONTENTS Page FIGURE 16. Map of Stud Horse prospect._i--___-__-______--_____- 77 17. Photographs showing prospect localities in typical chan­ nels filled with Shinarump Member of the Chinle For- 80 18. Map of Yellow Jacket prospect- 82 19. Map of Betty Jack prospect.__ 86 20. Map of Dream prospect.______ 90 TABLES Page TABLE 1. Uranium and organic