Geology and Ground Water in the Central Part of Apache County, Arizona By J. P. AKERS GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1771 Prepared in cooperation with the Arizona State Land Department UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Abstract,..-_________-______________-_--_--__-__-_-___-_---__----_ 1 Introduction-____________-_-________-___-----_----_-__-_----_-_--_ 2 Purpose, cooperation, and acknowledgments______________________ 2 Location and accessibility. _____________________________________ 2 Fieldwork.________________.___..____.___-_____.__-_______.___ 3 Well-numbering system.____-___---_______________-__--__-_____ 4 Previous investigations.--___-_________-_________-_-_--_-_-_--__ 4 Geography_ _____-_______-____-____..____-_-----____-__-____-_--__ 5 Physiography_ __ _ _-___________--____-__-_-____-___----___-__- 5 Climate.__--______-__-_-_--___--___----_--____-_--_-_-_--___- 6 Drainage-__-_________-____-___--____-____-___--_----___--_--_ 7 Vegetation.-._ _______-_____-____-_-__-___----_--_----__---_-__ 9 Industry and population____-___-_-__-_--__----_--_-------_--__- 9 Geology._________________________________________________________ 11 Geologic history.___-____-______--__---_--____---_-__-__--..--_- 11 Stratigraphy.___________________.._-__--___-___-..____.-_-__-_-_- 18 Sedimentary rocks_________________________________________ 18 Pennsylvanian and Permian rocks_______________________ 18 Supai Formation. _________________________________ 20 Permian rocks__ _____________-_______________--_-_.._--- 20 Coconino Sandstone-______________________________ 20 Kaibab Limestone,_____________--_-__-______--_-__ 21 Pre-Moenkopi unconformity-___________________________ 23 Triassic rocks_ __-____-_-_-_____________________-_-_-_- 24 Moenkopi Formation..- ___________________________ 24 Wupatki and Moqui Members- __._-____-_-_-___ 24 Holbrook Member.______-___-_-___-_____-__--_ 24 Pre-Chinle unconformity_____-__-____-_-_--________--_- 27 Chinle Formation-..-______________________________ 27 Shinarump Member.__________________________ 29 Mesa Redondo Member of Cooley_______________ 30 Petrified Forest Member.,___---__-____-____-__ 30 Owl Rock Member. __-______-_-__-__--__-_____ 32 Pre-Wingate unconformity._____________________________ 32 Wingate Sandstone-_______________________________ 33 Pre-Late Cretaceous unconformity.______________________ 34 Cretaceous rocks_ _____________________________________ 34 Dakota Sandstone.________________________________ 35 Mancos Shale.____________________________________ 36 Sedimentary rocks undifferentiated__________________ 37 Tertiary rocks___________________________________-__-_- 37 Eocene(?) sedimentary rocks_________________-_---_- 38 Datil Formation_____________-__--_________-_---- 39 Pre-Bidahochi erosion surfaces. ________________---__--_- 39 in IV CONTENTS Geology Continued Stratigraphy Continued Sedimentry rocks Continued Pre-Bidahochi erosion surfaces Continued Page Bidahochi Formation.__________----___-___-_______ 40 Lower member.______-______-_----__-___-_____ 42 Middle volcanic member.______________________ 43 Upper member._______________________________ 44 Age and relation_____________________________ 46 Quaternary deposits.._____-______-___-_____..__--______ 47 Terrace deposits.._________________________________ 47 Deposits underlying lava___________________________ 48 Travertine depostis._______________________________ 48 Alluvial deposts.__________________________________ 49 Eolian deposits..__________________________________ 50 Landslide deposits.________________________________ 50 Igneous rocks_____________________________________________ 51 Basement rock_ _______________________________________ 51 Extrusive igneous rock _________________________________ 51 Structure......_______________________________________________ 52 Folds-___________________________________________________ 53 Anticlines __-____-_______________--____-_---___-__--._ 53 Monoclines ___________________________________________ 54 Faults.__ _______________________________________________ 55 Age of structures______---_______--_________--_---_--___-__ 55 Ground water,____________________________________________________ 55 Coconino Sandstone.-_-__-____-__-_-_-___----_----_--__-_____- 61 Kaibab Limestone.____-__________--___________--__--__--_-____ 62 Moenkopi Formation__________________________________________ 67 Chinle Formation. ____________________________________________ 68 Dakota Sandstone_____________________________________________ 69 Upper Cretaceous rocks undifferentiated__________________________ 70 Tertiary sedimentary rocks_____________________________________ 72 Bidahochi Formation. _________________________________________ 72 Quaternary sediments-_________________________________________ 74 Quaternary alluvium.__________________________________________ 74 Volcanic rocks ___________-_-__-_--_-___-___-__--_-----_-_-_--_ 76 Regional hydrology.________________________________________________ 76 Water-level fluctuations____________________________________________ 81 Areas of potential ground-water development. _-____-__--__-__--_-_-__ 83 References cited.__-___-__-________________--__------_----__---_--_ 98 Index._-___-_-_---__-___--__--__-____---_-------_----------_----_ 103 CONTENTS ILLUSTRATIONS [Plates are in pocket] PLATE 1. Geologic map and sections. 2. Map showing configuration of the base of the Bidahochi Formation and of the water table in the Bidahochi Forma­ tion. 3. Map showing configuration of water table in the Coconino Sandstone and Kaibab Limestone. Page FIGURE 1. Map showing central part of Apache County and adjacent areas__ ______-____--__-____-_-___-__-___-___-__-_____ 3 2. Quaternary cinder eone______--___-----_--__---------_-__ 6 3. Typical habitat of range grasses and forage._-_______-___-_ 10 4. Map showing approximate locations of highland areas and the Cordilleran geosyncline in Paleozoic and part of Mesozoie time.-_---_-____-_-__---_-----_-__---_--_----------- 12 5. Map showing generalized distribution in the subsurface of the Kaibab Limestone and the quality of water the Kaibab contains. ____________________________________________ 14 6. Isopach map of the Chinle Formation.____________________ 16 7. Three units in the Kaibab Limestone.____________________ 22 8. Diagrammatic sketch showing relation of the Holbrook Mem­ ber to the other members of the Moenkopi Formation..-. 25 9. Contact of the Owl Rock Member of the Chinle Formation and the Wingate Sandstone.-______-______-._--_--_---- 33 10. Section along C-C'______.-_.--.--.--.--.----..----_.--. 41 11. Lower member of the Bidahochi Formation overlying the Chinle Formation.___________--___-__-_-_-_-_---__--_ 42 12. Crossbedding in the eolian facies of the upper member of the Bidahochi Formation._________-______-_---_-___-___-_ 45 13. Drawdown of water levels in the Coconino Sandstone at various times and at various distances______-___-_-_-__ 66 14. Map showing generalized areas of potential ground-water development from Cretaceous rocks.___-___-___-__-__-__ 71 15. Map showing generalized areas of potential ground-water development from the Bidahochi Formation and from volcanic rocks and Quaternary sediments._______________ 73 16. Map showing generalized areas where ground water can be developed in alluvium_________________________________ 75 17. Synoptic diagram showing relations of recharge area, direc­ tion of ground-water movement, and piezometric surface of water_____________________________________________ 77 18. Synoptic structure contour map_ ________-__-_____________ 79 19. Water levels in selected wells. _ __________________________ 82 20. Discharge of Concho Spring. ___________-___-_-____-_--__ 82 21. Map showing areas of potential development of irrigation water from the Coconino Sandstone ___________________ 84 VI CONTENTS TABLES Page TABLE 1. Average annual discharge, maximum discharge, and minimum discharge of the Little Colorado River at selected gaging stations in the central part of Apache County.___________ 7 2. Generalized section of sedimentary rocks in the central part of Apache County_--__-_____-______---__--__----_--______ 19 3. Records of selected ground-water supplies in the central part of Apache County.----__-______---_-____---_-_____-__---_ 56 4. Hydrologic characteristics of the Coconino Sandstone near Holbrook and Joseph City_------_-_-----_-----____-_--_- 62 5. Chemical analyses of ground water in the central part of Apache County------__-____-_______--___-___-________-__--___ 64 6. Selected drillers' logs of wells in the central part of Apache County_______________________________________________ 85 GEOLOGY AND GROUND WATER IN THE CENTRAL PART OF APACHE COUNTY, ARIZONA By J. P. AKERS ABSTRACT The central part of Apache County, Ariz., includes an area of about 3,300 square miles between the Navajo Indian Reservation to the north and U.S. Highway 60 to the south. Sedimentary rocks in the area range from Penn- sylvanian to Quaternary in age and from 2,000 to more than 6,000 feet in thickness. The strata were tilted to the northeast, and part of the Upper Triassic and all the Jurassic and Lower Cretaceous rocks were eroded away before strata of Late Cretaceous age were deposited. Basaltic lava flows and cinder cones, representing four general periods of eruption