DOCSLIB.ORG

Part of Western Arizona

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Part of Western Arizona DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR 352 GEOLOGIC EECONNAISSANCE OF A PART OF WESTERN ARIZONA BY WILLIS T. LEE WITH NOTES ON THE IGNEOUS ROCKS OF WESTERN ARIZONA BY ALBERT JOHANNSEN WASHINGTON GOVERNMENT PRINTING OFFICE 1908 CONTENTS. Page. Introduction.............................................................. 9 Purpose of the investigation.............:.............................. 9 Extent and character of the investigation................................ 9 Summary of previous knowledge....................................... 10 General geography........................................................: 11 Relation to surrounding regions......................................... 11 Topography........................................................... 12 General character................................................. 12 Mountains........................................................ 13 Valleys and plains.................................................. 14 Descriptive geology........................................................ 14 Rock formations........................................................ .1.4 Pre-Cambrian..................................................... 14 Cambrian.......................................................... 15 Carboniferous..................................................... 15 Tertiary... ^...................................................... 16 Eruptive rocks................................................ 16 Greggs breccia................................................ 17 Quaternary........................................................ 17 Temple Bar conglomerate....................................... 17 Chemehuevis gravel............................................ 18 Basalt flows......................;............................. 18 Geographic and geologic details of highlands................................. 18 Grand AYash Cliffs..................................................... 18 Location........:................................................. 18 Topographic features.............................................. 19 Rock masses...................................................... 19 Cottoiiwood and Aquarius cliffs.......................................... 19 Location.......................................................... 19 Topographic features............................................... 20 Rock masses...................................................... 20 Yampai Cliffs.......................................................... 20 Location.......................................................... 20 Topographic features..............................;....,.......-... 20 Rock masses...................................................... 21 Truxton Plateau..................................................'.... 21 Location.......................................................... 21 Topographic features.............................................. 21 Rock masses...................................................... 21 Aquarius Mountains.................................................... 22 Location.......................................................... 22 Topographic features.............................................. 22 Rock masses...................................................... 22 ' 3 4 CONTENTS. Geographic and geologic details of highlands Continued. Page. Artillery Mountains.".................................................. 22 Location.......................................................... 22 Topographic features.............................................. 22 Rock masses. ..................................................... 22 White Hills.......................................................... 23 Location........................................................... 23 Topographic features.............................................. 23 Rock masses...................................................... 23 Cerbat Mountains..................................................... 23 Location.......................................................... 23 Topographic features.......................................'....... 23 Rock masses...................................................... 23 Structure.......................................................... 24 Hualpai Mountains.................................................... 24 Location.......................................................... 24 Topographic features.............................................. 24 Rock masses...................................................... 25 Structure.......................................................... 25 Aubrey Hills........................................................... 25 Location.......................................................... 25 Topographic features.............................................. 25 Rock masses...................................................... 25 Black Mountains................................:...................... 25 Location.......................................................... 25 Topographic features..........:................................... 25 Rock masses...................................................... 26 Black Mesa............................................................ 26 Location.......................................................... 26 Topographic features.............................................. 26 Rock masses...................................................... 27 Mohave Mountains..................................................... 27 Location.......................................................... 27 Topographic features.............................................. 27 Rock masses...................................................... 28 Harcuvar and Harquahala Mountains.................................... 28 Location.......................................................... 28 Topographic features............................................... 28 Rock masses...................................................... 28 Buckskin Mountains.................................................... 28 Location.......................................................... 28 Topographic features...............:.............................. 28 Rock masses...................................................... 29 Palomas and Dome Rock ranges........................................ 29 Geographic and geologic details of valleys................................... 29 Colorado Valley........................................................ 29 General statement.................................................. 29 Mouth of Grand Canyon........................................... 30 Grand Wash Trough................................................ 30 Haulpai Wash...................................................... 33 Virgin Canyon..................................................... 34 Temple Bar....................................................... 35 Virgin Valley..................................................... 36 Boulder Canyon............ r ............... r ...................... 36 CONTENTS. 5 Geographic and geologic details of valleys Continued. Page. Colorado Valley Continued. ' ' Las Vegas Wash................................................... 37 Black Canyon..................................................... 37 Cottonwood Valley................................................ 37 Pyramid Canyon................................................... 38 Mohave Valley..................................................... 41 The Needles...................................................... 42 ^_ Chemehuevis Valley................................................ 43 Aubrey Canyon. .......^.......................................... 44 Great Colorado Valley.............................................. 45 Chocolate Mountains............................................... ' 46 J Hualpai Valley........................................................ 48 Location and character............................................ 48 Structure.......................................................... 50 Big Sandy Valley...................................................... 50 Location and character............................................ 50 Rock formations.................................................... 51 Structure.......................................................... 51 / Signal Canyon........................................................ 52 Detrital-Sacramento A^alley............................................. 52 Location and character............................................ 52 Detrital filling.................................................... 53 Williams Valley.....................!.................................. 53 Location and character............................................ 53 Rock formations.................................................... 54 Other valleys........................................................... 55 Location and character... ^......................................... 55 Detrital filling........:........................................... 55 Geologic history............................................................ 56 Introductory statements................................................ 56 Pre-Cambrian conditions............................................... 56 Crystalline rocks................................................... 56 Sedimentation....................................................
Load more

Recommended publications
  • The Lower Gila Region, Arizona
    DEPARTMENT OF THE INTERIOR HUBERT WORK, Secretary UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, Director Water-Supply Paper 498 THE LOWER GILA REGION, ARIZONA A GEOGBAPHIC, GEOLOGIC, AND HTDBOLOGIC BECONNAISSANCE WITH A GUIDE TO DESEET WATEEING PIACES BY CLYDE P. ROSS WASHINGTON GOVERNMENT PRINTING OFFICE 1923 ADDITIONAL COPIES OF THIS PUBLICATION MAT BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 50 CENTS PEE COPY PURCHASER AGREES NOT TO RESELL OR DISTRIBUTE THIS COPT FOR PROFIT. PUB. RES. 57, APPROVED MAT 11, 1822 CONTENTS. I Page. Preface, by O. E. Melnzer_____________ __ xr Introduction_ _ ___ __ _ 1 Location and extent of the region_____._________ _ J. Scope of the report- 1 Plan _________________________________ 1 General chapters _ __ ___ _ '. , 1 ' Route'descriptions and logs ___ __ _ 2 Chapter on watering places _ , 3 Maps_____________,_______,_______._____ 3 Acknowledgments ______________'- __________,______ 4 General features of the region___ _ ______ _ ., _ _ 4 Climate__,_______________________________ 4 History _____'_____________________________,_ 7 Industrial development___ ____ _ _ _ __ _ 12 Mining __________________________________ 12 Agriculture__-_______'.____________________ 13 Stock raising __ 15 Flora _____________________________________ 15 Fauna _________________________ ,_________ 16 Topography . _ ___ _, 17 Geology_____________ _ _ '. ___ 19 Bock formations. _ _ '. __ '_ ----,----- 20 Basal complex___________, _____ 1 L __. 20 Tertiary lavas ___________________ _____ 21 Tertiary sedimentary formations___T_____1___,r 23 Quaternary sedimentary formations _'__ _ r- 24 > Quaternary basalt ______________._________ 27 Structure _______________________ ______ 27 Geologic history _____ _____________ _ _____ 28 Early pre-Cambrian time______________________ .
    [Show full text]
  • Mineral Resources of the Harquahala Mountains Wilderness Study Area, La Paz and Maricopa Counties, Arizona
    2.SOB nH in ntoiOGIGM. JAN 3 1 1989 Mineral Resources of the Harquahala Mountains Wilderness Study Area, La Paz and Maricopa Counties, Arizona U.S. GEOLOGICAL SURVEY BULLETIN 1701-C Chapter C Mineral Resources of the Harquahala Mountains Wilderness Study Area, La Paz and Maricopa Counties, Arizona By ED DE WITT, S.M. RICHARD, J.R. HASSEMER, and W.F. HANNA U.S. Geological Survey J.R. THOMPSON U.S. Bureau of Mines U.S. GEOLOGICAL SURVEY BULLETIN 1701 MINERAL RESOURCES OF WILDERNESS STUDY AREAS- WEST-CENTRAL ARIZONA AND PART OF SAN BERNARDINO COUNTY, CALIFORNIA U. S. GEOLOGICAL SURVEY Dallas L Peck, Director UNITED STATES GOVERNMENT PRINTING OFFICE: 1988 For sale by the Books and Open-File Reports Section U.S. Geological Survey Federal Center Box 25425 Denver, CO 80225 Library of Congress Cataloging-in-Publlcatlon Data Mineral resources of the Harquahala Mountains wilderness study area, La Paz and Maricopa counties, Arizona. (Mineral resources of wilderness study areas west-central Arizona and part of San Bernardino County, California ; ch. C) (U.S. Geological Survey bulletin ; 1701-C) Bibliography: p. Supt. of Docs, no.: I 19.3:1701-C 1. Mines and mineral resources Arizona Harquahala Mountains Wilderness. 2. Harquahala Mountains (Ariz.) I. DeWitt, Ed. II. Series. III. Series: U.S. Geological Survey bulletin ; 1701. QE75.B9 no. 1701-C 557.3 s [553'.09791'72] 88-600012 [TN24.A6] STUDIES RELATED TO WILDERNESS Bureau of Land Management Wilderness Study Areas The Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976) requires the U.S. Geological Survey and the U.S.
    [Show full text]
  • 2020-2021 Arizona Hunting Regulations
    Arizona Game and Fish Department 2020-2021 Arizona Hunting Regulations This publication includes the annual regulations for statewide hunting of deer, fall turkey, fall javelina, bighorn sheep, fall bison, fall bear, mountain lion, small game and other huntable wildlife. The hunt permit application deadline is Tuesday, June 9, 2020, at 11:59 p.m. Arizona time. Purchase Arizona hunting licenses and apply for the draw online at azgfd.gov. Report wildlife violations, call: 800-352-0700 Two other annual hunt draw booklets are published for the spring big game hunts and elk and pronghorn hunts. i Unforgettable Adventures. Feel-Good Savings. Heed the call of adventure with great insurance coverage. 15 minutes could save you 15% or more on motorcycle insurance. geico.com | 1-800-442-9253 | Local Office Some discounts, coverages, payment plans and features are not available in all states, in all GEICO companies, or in all situations. Motorcycle and ATV coverages are underwritten by GEICO Indemnity Company. GEICO is a registered service mark of Government Employees Insurance Company, Washington, DC 20076; a Berkshire Hathaway Inc. subsidiary. © 2019 GEICO ii ARIZONA GAME AND FISH DEPARTMENT — AZGFD.GOV AdPages2019.indd 4 4/20/2020 11:49:25 AM AdPages2019.indd 5 2020-2021 ARIZONA HUNTING4/20/2020 REGULATIONS 11:50:24 AM 1 Arizona Game and Fish Department Key Contacts MAIN NUMBER: 602-942-3000 Choose 1 for known extension or name Choose 2 for draw, bonus points, and hunting and fishing license information Choose 3 for watercraft Choose 4 for regional
    [Show full text]
  • Ambient Groundwater Quality of the Detrital Valley Basin: an ADEQ 2002 Baseline Study
    Ambient Groundwater Quality of the Detrital Valley Basin: An ADEQ 2002 Baseline Study normal pool elevation of Lake Mead. Dolan Springs is the largest community in the basin. In the DET, 27 percent of land is managed by the National Park Service as part of the Lake Mead National Recreational Area. The remainder is managed by the Bureau of Land Management (42 percent) and State Trust land (9 percent) or consists of private lands (22 percent). III. Hydrology Groundwater from the alluvial aquifer underneath Detrital Valley is the principle water source in the basin and has the ability to supply up to 150 gallons per minute (gpm).3 However, depths to groundwater, approaching 800 feet below land surface (bls) in the valley, make tapping this aquifer for 2 Figure 1. In a bit of hydrologic serendipity, during the course of ADEQ’s study of the Detrital domestic use an expensive proposition. Valley basin, Lake Mead receeded to levels low enough to expose Monkey Cove Spring for the first time since July 1969. The spring flowed at an amazing 1,200 gallons per minute in 1964. I. Introduction factsheet reports upon the results of groundwater quality investigations in The Detrital Valley Groundwater Basin the DET and is a summary of the more (DET), traversed by U.S. Highway 93, extensive report produced by the is roughly located between the city of Arizona Department of Environmental Kingman and Hoover Dam on the Quality (ADEQ).1 Colorado River in northwestern Arizona (Map 1). Although lightly populated II. Background with retirement and recreation-oriented communities, the recent decision to The DET is approximately 50 miles construct a Hoover Dam bypass route long (north to south) and 15 miles wide for U.S.
    [Show full text]
  • People of Snowy Mountain, People of the River: a Multi-Agency Ethnographic Overview and Compendium Relating to Tribes Associated with Clark County, Nevada
    Portland State University PDXScholar Anthropology Faculty Publications and Presentations Anthropology 2012 People of Snowy Mountain, People of the River: A Multi-Agency Ethnographic Overview and Compendium Relating to Tribes Associated with Clark County, Nevada Douglas Deur Portland State University, [email protected] Deborah Confer University of Washington Follow this and additional works at: https://pdxscholar.library.pdx.edu/anth_fac Part of the Social and Cultural Anthropology Commons, and the Sustainability Commons Let us know how access to this document benefits ou.y Citation Details Deur, Douglas and Confer, Deborah, "People of Snowy Mountain, People of the River: A Multi-Agency Ethnographic Overview and Compendium Relating to Tribes Associated with Clark County, Nevada" (2012). Anthropology Faculty Publications and Presentations. 98. https://pdxscholar.library.pdx.edu/anth_fac/98 This Report is brought to you for free and open access. It has been accepted for inclusion in Anthropology Faculty Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Pacific West Region: Social Science Series National Park Service Publication Number 2012-01 U.S. Department of the Interior PEOPLE OF SNOWY MOUNTAIN, PEOPLE OF THE RIVER: A MULTI-AGENCY ETHNOGRAPHIC OVERVIEW AND COMPENDIUM RELATING TO TRIBES ASSOCIATED WITH CLARK COUNTY, NEVADA 2012 Douglas Deur, Ph.D. and Deborah Confer LAKE MEAD AND BLACK CANYON Doc Searls Photo, Courtesy Wikimedia Commons
    [Show full text]
  • Geology of Cienega Mining District, Northwestern Yuma County, Arizona
    Scholars' Mine Masters Theses Student Theses and Dissertations 1965 Geology of Cienega Mining District, Northwestern Yuma County, Arizona Elias Zambrano Follow this and additional works at: https://scholarsmine.mst.edu/masters_theses Part of the Geology Commons Department: Recommended Citation Zambrano, Elias, "Geology of Cienega Mining District, Northwestern Yuma County, Arizona" (1965). Masters Theses. 7104. https://scholarsmine.mst.edu/masters_theses/7104 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. GEOLOGY OF CIENEGA MINING DISTRICT, NORTHWESTERN YUM.1\, COUNTY, ARIZONA BY ELIAS ZAMBRANO I J'i~& A THESIS submitted to the faculty of the UNIVERSITY OF MISSOURI AT ROLLA in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE IN GEOLOGY Rolla, Missouri 1965 ~!'Approved by ~2/~advisor) ~ ~·-~~ ii ABSTRACT In the mapped area three metamorphic units crop out: calc-silicates and marble, gneiss, and a conglomerate- schist section. The first one consists of a series of intercalations of calc-silicate rocks, local marbles, and greenschist. Quartzite appears in the upper part of the section. This section passes transitionally to the gneiss, which is believed to be of sedimentary origin. Features indicative of sedimentary origin include inter­ calation with marble, relic bedding which can be observed locally, intercalation of greenschist clearly of sedimentary origin, lack of homogeneity in composition with both lateral and vertical variation occurring, roundness of zircon grains, and lack of zoning in the feldspars.
    [Show full text]
  • The Maricopa County Wildlife Connectivity Assessment: Report on Stakeholder Input January 2012
    The Maricopa County Wildlife Connectivity Assessment: Report on Stakeholder Input January 2012 (Photographs: Arizona Game and Fish Department) Arizona Game and Fish Department In partnership with the Arizona Wildlife Linkages Workgroup TABLE OF CONTENTS LIST OF FIGURES ............................................................................................................................ i RECOMMENDED CITATION ........................................................................................................ ii ACKNOWLEDGMENTS ................................................................................................................. ii EXECUTIVE SUMMARY ................................................................................................................ iii DEFINITIONS ................................................................................................................................ iv BACKGROUND ................................................................................................................................ 1 THE MARICOPA COUNTY WILDLIFE CONNECTIVITY ASSESSMENT ................................... 8 HOW TO USE THIS REPORT AND ASSOCIATED GIS DATA ................................................... 10 METHODS ..................................................................................................................................... 12 MASTER LIST OF WILDLIFE LINKAGES AND HABITAT BLOCKSAND BARRIERS ................ 16 REFERENCE MAPS .......................................................................................................................
    [Show full text]
  • Newberry/Dead Mountains Scenic Backcountry Drive the 10-Mile One-Way Drive Is on Bureau of Land Management Public Lands
    Newberry/Dead Mountains Scenic Backcountry Drive The 10-mile one-way drive is on Bureau of Land Management public lands. However, it is better to take this as a loop trail (see directions) so you don’t have to backtrack and can see other attractions. Although the road is gravel, it is in good condition and can be navigated by 2-wheel drive sedan vehicles, although high clearance is preferable. This particular scenic drive offers a wide range of vistas. Looking north are the Newberry Mountains with the prominent and sacred Spirit Mountain looming above the horizon. Looking south are the Dead Moun- tains which are also sacred to the native Indian tribes in the area. To the west are the granitic crystal hills with interesting rock formations. To the east is the Colorado River Valley and the high peaks of the Hualapai Range in Arizona as backdrop. The green fields along the Colorado River in this area are part of the Fort Mojave Indian Reservation. The Fort Mojave Indian Reservation covers nearly 42,000 acres in the tri-state area of Arizona, California, and Nevada. The Mojave Indians are Pipa Aha Macav — “The People By The River.” Mojave culture traces the earthly origins of its people to Spirit Mountain. Newberry Mountains Newberry Mountains Prior to the arrival of white settler to the region, the Mojave Indians were prosperous farmers with well- established villages and trade networks that stretched as far away as the Pacific Ocean. In the 16th Century, the time the Spanish arrived in the territory, the Mojave’s were the largest concentration of people in the Southwest.
    [Show full text]
  • Summits on the Air – ARM for the USA (W7A
    Summits on the Air – ARM for the U.S.A (W7A - Arizona) Summits on the Air U.S.A. (W7A - Arizona) Association Reference Manual Document Reference S53.1 Issue number 5.0 Date of issue 31-October 2020 Participation start date 01-Aug 2010 Authorized Date: 31-October 2020 Association Manager Pete Scola, WA7JTM Summits-on-the-Air an original concept by G3WGV and developed with G3CWI Notice “Summits on the Air” SOTA and the SOTA logo are trademarks of the Programme. This document is copyright of the Programme. All other trademarks and copyrights referenced herein are acknowledged. Document S53.1 Page 1 of 15 Summits on the Air – ARM for the U.S.A (W7A - Arizona) TABLE OF CONTENTS CHANGE CONTROL....................................................................................................................................... 3 DISCLAIMER................................................................................................................................................. 4 1 ASSOCIATION REFERENCE DATA ........................................................................................................... 5 1.1 Program Derivation ...................................................................................................................................................................................... 6 1.2 General Information ..................................................................................................................................................................................... 6 1.3 Final Ascent
    [Show full text]
  • Miocene Low-Angle Normal Faulting and Dike Emplacement, Homer Mountain and Surrounding Areas, Southeastern California and Southernmost Nevada
    Miocene low-angle normal faulting and dike emplacement, Homer Mountain and surrounding areas, southeastern California and southernmost Nevada JON E. SPENCER* U.S. Geological Survey, 345 Middlefleld Road, Menlo Park, California 94025 ABSTRACT tions, differed radically from the state of that collectively accommodated as much as 50% stress in the upper plate, as inferred from to 100% extension of upper-plate rocks (Ander- Homer Mountain and surrounding regions fault geometry. Low-angle faulting and east- son, 1971). In many areas, normal faults within are within, or adjacent to, the western part of northeast-west-southwest distension of up- upper-plate rocks merge with, or are truncated a broad region of low-angle normal faults ex- per-plate rocks reflect regional reduction of by, a basal, subhorizontal fault often referred to posed within the lower Colorado River compression in the east-northeast-west- as a "detachment fault" (for example, see Davis trough. During middle Miocene time, upper- southwest direction and associated large- and others, 1980). The term "detachment fault" plate rocks in the Homer, Sacramento, Dead, scale east-northeast-west-southwest crustal is used here to indicate a low-angle normal fault and Newberry Mountains moved eastward or extension. In contrast, concave-upward flex- that formed at a low angle (for example, Wer- northeastward, relative to the lower plate, ure of the lower plate, in response to tectonic nicke and others, 1984; Reynolds and Spsncer, above single or multiple low-angle normal denudation and resultant isostatic uplift, is in- 1985). The interpretation that detachment faults faults. Deposition of coarse clastic sedimen- ferred to have produced local subhorizontal are rooted faults that accommodate crustal ex- tary rocks occurred during extensional fault- compression at shallow crustal levels in the tension (Wernicke, 1981; Howard and John, ing and was accompanied by, and closely lower plate that overwhelmed the regional 1983; Davis and others, 1983; Allmendinger followed by, eruption of basaltic volcanics.
    [Show full text]
  • Distribution and Trans-Highway Movements of Desert Bighorn Sheep in Northwestern Arizona
    US93 Bighorn Sheep Study: Distribution and Trans-Highway Movements of Desert Bighorn Sheep in Northwestern Arizona Final Report 576 Prepared by: Ted McKinney and Thorry Smith Arizona Game and Fish Department Research Branch 2221 West Greenway Road Phoenix, AZ 85023 January 2007 Prepared for: Arizona Department of Transportation 206 South 17th Avenue Phoenix, Arizona 85007 In cooperation with U.S. Department of Transportation Federal Highway Administration The Arizona Department of Transportation and Federal Highway Administration provided funding for this research. The research team thanks AGFD personnel J. Ng for field assistance in monitoring track beds and conducting ground surveys, and K. Bristow and M. Crabb for assistance in collecting radiocollars following drop-off. The research team also thanks J. Barnes, D. Fletcher, and C. Velez (National Park Service) for field assistance. N. Dodd, J. Gagnon, and S. Boe (AGFD) provided analytical assistance. Helicopter pilots M. Brinkworth and N. Lopez (Papillon Helicopters) and S. Sprague (AGFD) assisted with captures. AGFD pilots E. Cash, B. Coffman, B. David, S. Sunde, and D. Hunt assisted with aerial telemetry. D. Conrad and L. Phoenix (AGFD) were net- gunners during captures, and J. Wills and K. Morgan (AGFD) assisted with captures and recovery of bighorn mortalities. G. Erickson (AGFD) and C. Largent (National Park Service) also provided valuable information during the study. C. O’Brien and R. Schweinsburg (AGFD) provided valuable editorial review of this report. The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Arizona Department of Transportation or the Federal Highway Administration.
    [Show full text]
  • Utah Geological Association Publication 30.Pub
    Utah Geological Association Publication 30 - Pacific Section American Association of Petroleum Geologists Publication GB78 239 CENOZOIC EVOLUTION OF THE NORTHERN COLORADO RIVER EXTEN- SIONAL CORRIDOR, SOUTHERN NEVADA AND NORTHWEST ARIZONA JAMES E. FAULDS1, DANIEL L. FEUERBACH2*, CALVIN F. MILLER3, 4 AND EUGENE I. SMITH 1Nevada Bureau of Mines and Geology, University of Nevada, Mail Stop 178, Reno, NV 89557 2Department of Geology, University of Iowa, Iowa City, IA 52242 *Now at Exxon Mobil Development Company, 16825 Northchase Drive, Houston, TX 77060 3Department of Geology, Vanderbilt University, Nashville, TN 37235 4Department of Geoscience, University of Nevada, Las Vegas, NV 89154 ABSTRACT The northern Colorado River extensional corridor is a 70- to 100-km-wide region of moderately to highly extended crust along the eastern margin of the Basin and Range province in southern Nevada and northwestern Arizona. It has occupied a criti- cal structural position in the western Cordillera since Mesozoic time. In the Cretaceous through early Tertiary, it stood just east and north of major fold and thrust belts and also marked the northern end of a broad, gently (~15o) north-plunging uplift (Kingman arch) that extended southeastward through much of central Arizona. Mesozoic and Paleozoic strata were stripped from the arch by northeast-flowing streams. Peraluminous 65 to 73 Ma granites were emplaced at depths of at least 10 km and exposed in the core of the arch by earliest Miocene time. Calc-alkaline magmatism swept northward through the northern Colorado River extensional corridor during early to middle Miocene time, beginning at ~22 Ma in the south and ~12 Ma in the north.
    [Show full text]