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Cenozoic Geology of the By CHARLES B. HUNT UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1956 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director ' For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 75 cents (paper cover) Page Page Abstract. __________________________________________ 1 Cenozoic deposits Continued Tn troduction_______________________________________ 1. Upper Tertiary deposits (Miocene and Pliocene) Con. Purpose of report and acknowledgments____-________ 1 Deposits around the edges of the Colorado Plateau General geographic setting of the Colorado Plateau.__ 2 Continued Pre-Cambrian basement rocks._______________________ 11 San Juan Mountains.___-_--_----_-_-----___-_ 31 Summary of Paleozoic and Mesozoic stratigraphy._____ 11 Rio Grande Valley____________________________ 32 Cenozoic deposits.__________________________________ 15 Grand Wash trough_____________________._____ 33 Lower Tertiary deposits (Paleocene and Eocene)______ 15 Quaternary deposits____ ~__________________________ 35 Uinta Basin and High PJateaus___________________ 17 Pre-Wisconsin deposits. _________________________ 35 Nor tli Horn formation _________________________ 17 Wisconsin deposits._____________________________ 38 Flagstaff limestone and Wasatch formation in High Recent deposits._._____________________________ 38 Plateaus.__________________________________ ' 18 Cenozoic igneous rocks________.._____-_-_--__________ 39 Tuscher, Ohio Creek, and DeBeque formations. __ 18 General features._________________________________ 39 Colton and Wasatch formations in Uinta Basin._ 19 Early Tertiary igneous rocks.______________________ 42 Green River formation________________________ 19 Late Tertiary igneous rocks. _______________________ 42 Bridger formation.____________________________ 22 Laccolithic mountains-_______-----____-_-_-_____ 42 Uinta formation._____________________________ 22 Large central-type volcanoes- _ ___________________ Duchesne River formation _____________________ 22 Volcanic rocks and intrusions in the central part of the San Juan Basin_________________________________ 23 High Plateaus._______________________________ 48 Animas formation.__________________________ 23 Basalt and alkalic basalt series._-________--_--___ 49 Nacimiento formation (Puerco and Torrejon faunal Quaternary igneous rocks._________________________ 53 zones) _____________________________________ 24 Structural geology._________-_-____-_-____-----_____ 52 Wasatch (San Jose) formation, .(and Tiffany beds)_ 25 General features._________________________________ 53 Mogollon Rim....._______________________________ 25 Pre-Cenozoic structural elements___--______----____ 54 Deposits in adjoining areas_---_---_---_----__-_-_ 26 Cenozoic erogenic structures._______..__-____--____- 57 San Juan Mountains-_________________________ 26 Early Tertiary structures.___-_-_--_______--__-__ 57 Rio Grande Valley.___________________________ 26 Late Tertiary structures.________________________ 58 Southern Arizona.____________________________ 26 Quaternary structures.____-__-_---_______-___-__ 61 Upper Tertiary deposits (Miocene and Pliocene) _____ 26 Cenozoic igneous structures._______________________ 62 High Plateaus.-.-____________-_--------____-___ 26 Cenozoic epeirogenic structures.____________________ 63- Brian Head formation.._______________________ 26 Physiography._______________!_____________________ 64 Sevier River and Parunuweap formation_______._ 27 Climate and water supply-__-_-------_---------___- 64 Southern part of the Colorado Plateau. ___________ 29 Anteposition_ _ ___________________________________ 65 Bidahochi formation __________________________ 29 Colorado and Green Rivers-_______________________ 67 Chuska sandstone.____________________________ 29 Tributary streams._______________________________ 68 Datil formation_______________________________ 29 Erosion and geologic time.________________________ 71 Deposits at Peach Springs, Ariz________________ 30 Soils.___________________________________________ 71 Interior of the Plateau. __ _______________________ 30 Cenozoic history of the Plateau a hypothesis__--_-_._- 72 Deposits around the edges of the Colorado Plateau__ 30 Bibliography__ ___________________________________ 87 Uinta Basin area_________-_-_____-_-___--____ 30 Index._____________________________________________ 97 ILLUSTRATIONS Page Page FIGURE 1. Index map of the Colorado Plateau. _______ FIGURE 6. Soil formations on the Colorado Plateau.._. 9 2. Diagrammatic view of the Henry Mountains 7. Mineral deposits on the Colorado Plateau. __ 10 region._______________________________ 8. Isopach map showing thickness of Paleozoic 3. Diagrams showing formation of natural formations on the Colorado Plateau._____ 12 bridges.______________________________ 9. Cross section of basin under Black Mesa and 4. Climatic maps of Colorado, Utah, Arizona, of San Juan Basin______________________ 13 1 and New Mexico_---_-_-------_-_-----_ 10. Isopach map showing thickness of Mesozoic 5. Vegetation map of the Colorado Plateau.___ formations on the Colorado Plateau._____ 14 in IV CONTENTS Page Page- Cross section of Mogollon Rim, illustrating FIGURE 35. Geologic cross sections of San Francisco overlap of Upper Cretaceous formations Mountain and vicinity_________________ 48 southward onto Permian form;ations______ 15 36. Maps of some volcanic necks in the Navajo- 12. Correlation chart of Cenozoic formations on, Hopi fields.___________________________ 50 and adjacent to, the Colorado Plateau____ 16 37. Structure-contour map of the Colorado Pia- 13. Diagrammatic section of formations exposed teau________________________________ 52 in the western part of the Wasatch Plateau. 17 38. Section across the Zuni Mountain upwarp, 14. Cross section of Grand Hogback, near Meeker, N. Mex_____________________________ 53 Colo________________________________ 18 39. Sections across the Gallup-Zuni Basin, N. 15. Diagrammatic cross section of the Uinta Mex_.________________________________ 54 Basin north from Green River, Utah_____ 20 40. Generalized m.ap of part of eastern Utah and 16. Stratigraphic relations of the subdivisions of western Colorado ______________________ 55 the Green River formation in Colorado and 41. Cross section of fault blocks in High Plateaus Utah.________________________________ 20 southeast of Salina, Utah. ______________ 56 17. Sections from northwest to southeast in the 42. Block diagrams showing that part of Utah Green River Basin, Wyo. and Colo., show­ north of latitude 39° 30' at four stages in ing intertonguing of the Wasatch and Green Late Cretaceous time.__________________ 56 River formations.______________________ 21 43. Block diagram illustrating the faulted cast 18. Diagrammatic section across the San Juan edge of the Colorado Plateau, east of Mount Basin from Durango, Colo., to Pueblo Taylor, N. Mex________"________________ 58 Bonito, N. Mex________________________ 23 44. Tectonic map of part of the San Juan Basin 19. Diagram showing inferred Stratigraphic rela­ and the Rio Grande depression __________ 59 tions of Paleocene and Eocene formations 45. Diagrammatic section illustrating faulting on east side of San Juan Basin.__________ 24 east of Mesa Lucero____________________ 59 20. Map showing outcrop of Bidahochi formation 28 46. Sequence of late Tertiary and Quaternary 21. Cross section of the Defiance uplift_________ 29 events in the Mount Taylor volcanic field. 60 22. Geologic map and cross section of part of 47. Structure sections across the Hurricane fault Grand Wash trough.___________________ 34 zone showing four stages in its develop­ Cross section of valley fill in vicinity of Grand ment- _-_-__-_--_--_--_--_-__-___-_-._ 61 Wash trough. _________________________ 35 '48. Block diagrams illustrating stages in the de­ Diagrams illustrating four stages in the devel­ velopment of Lodore Canyon____________ 66 opment of pediments in the Colorado 49. Diagrams illustrating anteposition_________ 67 Plateau _______________________________ 6-37 50. Generalized view of south-central Utah look­ 25. Diagrammatic sections illustrating some ing north from the Utah-Arizona boundary common Stratigraphic relationships in the line______________________________ 69 alluvial deposits on the Colorado Plateau. 39 51. Generalized block diagrams representing 26. Sketch map illustrating distribution of Ceno­ stages in the physiographic history of upper zoic igneous rocks on the Colorado Plateau. 40 Paria Valley...___ __-_-_-_-___-__._-_._ 70 27. Variation diagrams showing proportions of 52. Block diagram of the San Juan Canyon across alkalis and silica in the igneous rocks in the Monument Upwarp_________________ 71 four parts of the Colorado Plateau_______ 41 53. The Colorado Plateau area in late Cretaceous 28. Diagrams illustrating the relationship be­ time__ ______________________________ 74 tween the stocks and the domes at the 54. The Colorado Plateau area in early Paleocene laccolithic mountains on the Colorado time__________________________________ 75 Plateau ________-__-_____-__-_-_----___ 43 55. The Colorado Plateau area in late Paleocene 29. Structure-contour map of the Henry Moun­ time____ _ _____________________________ 76 tains --_______-___--__----_---__-_____ 44 56. The Colorado Plateau in. early and middle 30. Ground plan of intrusions around the Mount Eocene time___________________________ 78 Ellen stock in the Henry Mountains____ 45 57.
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