DOCSLIB.ORG

Miocene Low-Angle Normal Faulting and Dike Emplacement, Homer Mountain and Surrounding Areas, Southeastern California and Southernmost Nevada

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read 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. extensional stress and prevented emplace- and others, 1983) is accepted here. Upper-plate fault blocks of Miocene volcanic ment of dikes oriented perpendicular to the Within areas of low-angle normal faulting, and sedimentary irocks and older, underlying direction of regional extension. North-south upper-plate rocks are generally tilted in one crystalline rocks sire tilted gently to steeply to crustal extension during dike emplacement dominant direction over areas that range from the west or southwest. Low-angle normal appears to have resulted from minor diver- hundreds to thousands of square kilometres. The faults have complex, sinuous traces due to the gence of lower-plate crustal blocks as they transport direction of upper-plate rocks, relative irregular form of fault surfaces. Antiformal were displaced in a west-southwest direction to lower-plate rocks, was usually in the direction warping and uplifnt of the lower plate about a away from the Colorado Plateau. opposite to the tilt direction of upper-plate fault north-south trending axis, due to tectonic blocks. On the basis of tilt directions and other denudation and isostatic rebound, divided the INTRODUCTION criteria, upper-plate rocks are inferred to have regionally east-thickening extensional alloch- moved in an east-northeast direction, relative to thon into separate synformal and wedge- The northern part of the Colorado River the lower plate, in all areas of the northern Colo- shaped components. The Homer Mountain trough, extending for -200 km from the Eldo- rado River trough except the northern Eldorado area lies within, c>r adjacent to, the synformal rado and northern Black Mountains southward and northern Black Mountains where tilt direc- component. through the Whipple, Buckskin, and Rawhide tions suggest westward displacement of lpper- Lower-plate rocks are intruded by numer- Mountains, is a zone of major middle Tertiary plate rocks. ous, middle Miocene, east-west-trending low-angle normal faulting. Low-angle faults, ex- The origin of large-scale warps of detachment dikes, which are in turn intruded by subhori- posed in every range along the west side of the fault surfaces is not completely understood. In zontal dikes. Both sets of dikes are cut and Colorado River in the northern Colorado River the northern Colorado River trough, the : rregu- displaced by low-angle normal faults except trough, place moderately to steeply tilted, mid- lar, undulatory shape of detachment fault sur- on the west flank of the Newberry Mountains dle Tertiary volcanic and sedimentary rocks and faces reflects interference between two sets of where an east-west-trending dike cuts the Mesozoic and Precambrian crystalline rocks approximately perpendicular folds or warps basal low-angle normal fault. K-Ar geochro- over Phanerozoic and Proterozoic plutonic and (Davis and others, 1980; Frost, 1981; Cameron nologic and field data establish the approxi- metamorphic rocks. These faults are inferred to and Frost, 1981) and/or original irregularities of mate synchroneiity of dike emplacement and be normal faults because they juxtapose upper- fault surfaces (John, 1984). Large, broad warps low-angle faulting. The state of stress in the crustal rocks (including, in many cases, syntec- with axes perpendicular to fault-movement di- lower plate, as inferred from dike orienta- tonic clastic sedimentary rocks) with underlying rection appear to be primarily the proc.uct of igneous and metamorphic rocks that evidently isostatic rebound accompanying and imme- acquired some of their characteristics at middle- diately following tectonic denudation (Rehrig *Present address: Arizona Bureau of Geology and crustal depths. Upper-plate rocks may be cut by Mineral Technolog]', 845 North Park Avenue, Tuc- and Reynolds, 1980; Howard and others, son, Arizona 85719. numerous listric and/or planar normal faults 1982a, 1982b; Spencer, 1982, 1984). Shorter Geological Society of America Bulletin, v. 96, p. 1140-1155, 12 figs., 1 table, September 1985. 1140 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/96/9/1140/3419452/i0016-7606-96-9-1140.pdf by guest on 01 October 2021 FAULTING AND DIKE EMPLACEMENT, CALIFORNIA AND NEVADA 1141 Figure 1. Simplified geologic map of the Homer Mountain area. Dashed line indicates approximate location of breakaway fault beneath Quaternary alluvium. wavelength (3-12 km), foldlike irregularities stress remains perpendicular to the walls of the are potential indicators of the orientation of of uncertain age and origin have axes parallel dikes. Rehrig and Heidrick (1976) used the principal stresses responsible for warping of de- to the east-northeast direction of upper-plate geometry of intrusive bodies in Arizona to infer tachment faults. displacement. the direction of least compressive stress during This paper results from a field and K-Ar Study of dikes and dike swarms is a relatively both the late Mesozoic-early Tertiary Laramide geochronologic study of the Homer Mountain simple method of constraining the orientations orogeny and middle Tertiary crustal extension. area in the western part of the northern Colo- of the principal stresses at the time of dike em- Their results are consistent with stress orienta- rado River trough that was directed at under- placement. Field, experimental, and theoretical tions inferred from the geometry of faults that standing the temporal and mechanical relation- studies all indicate that dikes adjust their course formed during Laramide and middle Tertiary ships between detachment faulting, fault-surface of propagation so that the minimum principal tectonism. Dikes in areas of detachment faulting irregularities, and dike swarms. The study area Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/96/9/1140/3419452/i0016-7606-96-9-1140.pdf by guest on 01 October 2021 1142 J. E. SPENCER Figure 2. Simplified geologic map of the southern end of the Piute Range. See Figure 1 for location. Geology from Spencer and Turner (1985). includes Homer Mountain, the southern end of pioneering study by Longwell (1945). Recon- distribution of rock types and faults in the south- the Piute Range, the northern Sacramento naissance mapping by geologists of the Southern ern Eldorado, Newberry, and northern Dead Mountains, and parts of the Dead and Newberry Pacific Land Company in the late 1950s re- Mountains. Mountains (Fig. 1). All of these ranges have vealed the great extent and the complex, irregu- Davis and others (1980) documented, many been strongly affected by middle Miocene de- lar form of detachment faults along the west side of the distinctive characteristics of detachment tachment faulting and/or dike emplacement. of the northern Colorado River trough. The faults in their study of the Whipple-Buekskin- This study outlines the lithologies and structures Southern Pacific geologists recognized most of Rawhide Mountains area, and they compiled of the Homer Mountain area and presents K-Ar the geologic relationships and the distribution of and simplified the mapping of the Southern Pa- geochronologic data that constrain the timing of rock types in the Homer Mountain area. Unfor- cific geologists and their own mapping of areas faulting, sedimer.tation, volcanism, and dike tunately, they did not publish the results of their of detachment faulting along the northern Colo- emplacement. Mechanical analysis of processes investigation, and although their maps were rado River trough. This
Load more

Recommended publications
  • 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]
  • The California Desert CONSERVATION AREA PLAN 1980 As Amended
    the California Desert CONSERVATION AREA PLAN 1980 as amended U.S. DEPARTMENT OF THE INTERIOR BUREAU OF LAND MANAGEMENT U.S. Department of the Interior Bureau of Land Management Desert District Riverside, California the California Desert CONSERVATION AREA PLAN 1980 as Amended IN REPLY REFER TO United States Department of the Interior BUREAU OF LAND MANAGEMENT STATE OFFICE Federal Office Building 2800 Cottage Way Sacramento, California 95825 Dear Reader: Thank you.You and many other interested citizens like you have made this California Desert Conservation Area Plan. It was conceived of your interests and concerns, born into law through your elected representatives, molded by your direct personal involvement, matured and refined through public conflict, interaction, and compromise, and completed as a result of your review, comment and advice. It is a good plan. You have reason to be proud. Perhaps, as individuals, we may say, “This is not exactly the plan I would like,” but together we can say, “This is a plan we can agree on, it is fair, and it is possible.” This is the most important part of all, because this Plan is only a beginning. A plan is a piece of paper-what counts is what happens on the ground. The California Desert Plan encompasses a tremendous area and many different resources and uses. The decisions in the Plan are major and important, but they are only general guides to site—specific actions. The job ahead of us now involves three tasks: —Site-specific plans, such as grazing allotment management plans or vehicle route designation; —On-the-ground actions, such as granting mineral leases, developing water sources for wildlife, building fences for livestock pastures or for protecting petroglyphs; and —Keeping people informed of and involved in putting the Plan to work on the ground, and in changing the Plan to meet future needs.
    [Show full text]
  • Geographic Names
    GEOGRAPHIC NAMES CORRECT ORTHOGRAPHY OF GEOGRAPHIC NAMES ? REVISED TO JANUARY, 1911 WASHINGTON GOVERNMENT PRINTING OFFICE 1911 PREPARED FOR USE IN THE GOVERNMENT PRINTING OFFICE BY THE UNITED STATES GEOGRAPHIC BOARD WASHINGTON, D. C, JANUARY, 1911 ) CORRECT ORTHOGRAPHY OF GEOGRAPHIC NAMES. The following list of geographic names includes all decisions on spelling rendered by the United States Geographic Board to and including December 7, 1910. Adopted forms are shown by bold-face type, rejected forms by italic, and revisions of previous decisions by an asterisk (*). Aalplaus ; see Alplaus. Acoma; township, McLeod County, Minn. Abagadasset; point, Kennebec River, Saga- (Not Aconia.) dahoc County, Me. (Not Abagadusset. AQores ; see Azores. Abatan; river, southwest part of Bohol, Acquasco; see Aquaseo. discharging into Maribojoc Bay. (Not Acquia; see Aquia. Abalan nor Abalon.) Acworth; railroad station and town, Cobb Aberjona; river, IVIiddlesex County, Mass. County, Ga. (Not Ackworth.) (Not Abbajona.) Adam; island, Chesapeake Bay, Dorchester Abino; point, in Canada, near east end of County, Md. (Not Adam's nor Adams.) Lake Erie. (Not Abineau nor Albino.) Adams; creek, Chatham County, Ga. (Not Aboite; railroad station, Allen County, Adams's.) Ind. (Not Aboit.) Adams; township. Warren County, Ind. AJjoo-shehr ; see Bushire. (Not J. Q. Adams.) Abookeer; AhouJcir; see Abukir. Adam's Creek; see Cunningham. Ahou Hamad; see Abu Hamed. Adams Fall; ledge in New Haven Harbor, Fall.) Abram ; creek in Grant and Mineral Coun- Conn. (Not Adam's ties, W. Va. (Not Abraham.) Adel; see Somali. Abram; see Shimmo. Adelina; town, Calvert County, Md. (Not Abruad ; see Riad. Adalina.) Absaroka; range of mountains in and near Aderhold; ferry over Chattahoochee River, Yellowstone National Park.
    [Show full text]
  • Desert Renewable Energy Conservation Plan Proposed Land
    DRECP Proposed LUPA and Final EIS CHAPTER III.8. CULTURAL RESOURCES III.8 CULTURAL RESOURCES This chapter presents the Affected Environment for the Land Use Plan Amendment (LUPA) Decision Area and the Desert Renewable Energy Conservation Plan (DRECP) area for cultural resources. These areas overlap, and in the following programmatic discussion are referred to broadly as the “California Desert Region.” More than 32,000 cultural resources are known in the DRECP area in every existing environmental context ⎼ from mountain crests to dry lake beds ⎼ and include both surface and subsurface deposits. Cultural resources are categorized as buildings, sites, structures, objects, and districts (including cultural landscapes and Traditional Cultural Properties) under the federal National Environmental Policy Act (NEPA) and the National Historic Preservation Act (NHPA). Historic properties are cultural resources included in, or eligible for inclusion in, the National Register of Historic Places (NRHP), maintained by the Secretary of the Interior (36 Code of Federal Regulations [CFR] 60.4). See Section III.8.1.1 for more information on federal regulations and historic properties. This chapter discusses three types of cultural resources classified by their origins: prehistoric, ethnographic, and historic. Prehistoric cultural resources are associated with the human occupation of California prior to prolonged European contact. These resources may include sites and deposits, structures, artifacts, rock art, trails, and other traces of Native American human behavior. In California, the prehistoric period began over 12,000 years ago and extended through the eighteenth century until 1769, when the first Europeans settled in California. Ethnographic resources represent the heritage of a particular ethnic or cultural group, such as Native Americans or African, European, Latino, or Asian immigrants.
    [Show full text]
  • Ca-Lower-Colorado-River-Valley-Pkwy
    I • I I I ) I I A REPORT TO THE CONGRESS OF THE UNITED STATES ---1 I 'I I I I THE LOWER I COLORADO I RIVER I VALLEY • PARKWAY I I D- '°'le> F; 1-e. ·• NFS- ' f\CAc:.+... \ V"C. , ~ P,of>oseol I ~~~~=-'~c f~l~~c~~w I THE LOWER COLORADO I filVERVALLEYPARKWAY I I I A proposal for a National Parkway and Scenic Recreation Road System along the Lower Colorado River Valley in 'I California, Arizona, and Nevada. I NATIONAL PARK .i DENVER SEfiViC I ·-.-:. a.t ..1flkllb""ll.--';,.i. n II"~ r.· " •· \..' ;: · I ;:~::::.;.;:;.:J I I I U.S. DEPARTMENT OF THE INTERIOR National Park Service I in cooperation with Lower Colorado River Office Bureau of Land Management • PLE~\SE RtTUR?j TO: I February 1969 I , lJnited States Department of the Interior OFFICE OF THE SECRETARY I WASHINGTON, D.C. 20240 I I Dear Mr. President: We are pleased to transmit herewith. a report on the feasibility anc;l desirability of developing a nation~l p;;i.rkwa,y and sc;enic recreation I road system within. the Lower C9l9rado River· Vaiiey in Arizona, Califo~nia, and Nevada, from the Lake Mead National Recreation I Area and Davis Dam on the north to the International Boup.d:;i.ry ~ith Mexico on the south in: the vicinity of San Luis, Arizqna arid Mexic.o.· . ·. ' .. ·.' . ·. I This :i;eport is based on ci. study 11,'lade by the Lower Col<;>rado River Office ap.d the NatiQnal :Par~ Service pf this Depa.rtmep.t with engineerin.g assistance by the Buqlau of Public Roads of the Departmep.t of .
    [Show full text]
  • Special Use Provisions in Wilderness Legislation
    University of Colorado Law School Colorado Law Scholarly Commons Getches-Wilkinson Center for Natural Books, Reports, and Studies Resources, Energy, and the Environment 2004 Special Use Provisions in Wilderness Legislation University of Colorado Boulder. Natural Resources Law Center Follow this and additional works at: https://scholar.law.colorado.edu/books_reports_studies Part of the Natural Resources and Conservation Commons, Natural Resources Law Commons, and the Natural Resources Management and Policy Commons Citation Information Special Use Provisions in Wilderness Legislation (Natural Res. Law Ctr., Univ. of Colo. Sch. of Law 2004). SPECIAL USE PROVISIONS IN WILDERNESS LEGISLATION (Natural Res. Law Ctr., Univ. of Colo. Sch. of Law 2004). Reproduced with permission of the Getches-Wilkinson Center for Natural Resources, Energy, and the Environment (formerly the Natural Resources Law Center) at the University of Colorado Law School. SPECIAL USE PROVISIONS IN WILDERNESS LEGISLATION Natural Resources Law Center University of Colorado School of Law 401 UCB Boulder, Colorado 80309-0401 2004 Table of Contents SPECIAL USE PROVISIONS IN WILDERNESS LEGISLATION ........................................................... 1 I. Overview ................................................................................................................................. 1 II. Specific Special Use Provisions............................................................................................. 1 A. Water Rights ....................................................................................................................
    [Show full text]
  • Final Programmatic Environmental Assessment
    Final Programmatic Environmental Assessment Quarry Operations –Yuma Area Office Lower Colorado River Region U.S. Department of the Interior Bureau of Reclamation Yuma Area Office Yuma, Arizona August 2007 Mission Statements The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian Tribes and our commitments to island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Final Programmatic Environmental Assessment Quarry Operations – Yuma Area Office Lower Colorado River Region prepared by Yuma Area Office Resource Management Office Environmental Planning and Compliance Group Jason Associates Corporation Yuma Office Contract No. 03-PE-34-0230 U.S. Department of the Interior Bureau of Reclamation Yuma Area Office Yuma, Arizona August 2007 Acronyms and Abbreviations ADEQ Arizona Department of Environmental Quality APCD Air Pollution Control District AQMD Air Quality Management District BCO Biological and Conference Opinion BMPs Best Management Practices BLM U.S. Bureau of Land Management CAAQS California Ambient Air Quality Standards CARB California Air Resources Board CESA California Endangered Species Act CFR Code of Federal Regulations CO Carbon monoxide CRFWLS Colorado River Front Work and Levee System CRIT Colorado River Indian Tribes DM Departmental Manual DTSC Department
    [Show full text]
  • Federal Register/Vol. 81, No. 48/Friday, March 11, 2016/Notices
    12938 Federal Register / Vol. 81, No. 48 / Friday, March 11, 2016 / Notices Controlled substance means any substance State, or local government officer or (including chemical) device on public lands. so designated by law whose availability is employee in the scope of their duties; This prohibition includes, but is not limited restricted, including, but not limited to, members of any organized law enforcement, to, any homemade or manufactured bomb, narcotics, stimulants, depressants, rescue, or fire-fighting force in performance cannon, mortar, or similar device. hallucinogens, and marijuana. of an official duty; and any person whose Destructive device means any type of activities are authorized in writing by the Enforcement weapon, by whatever name known, which Bureau of Land Management. Any person who violates any of these will, or which may be readily converted to 4. All persons must abide by all Federal supplementary rules may be tried before a expel a projectile by the action of an and State laws, rules, and regulations United States Magistrate and fined in explosive or other propellant, the barrel or pertaining to firearms and weapons for all accordance with 18 U.S.C. 3571, imprisoned barrels of which have a bore of more than shooting activities on public lands. no more than 12 months under 43 U.S.C. 0.60 caliber, except a shotgun or shotgun 5. No person shall, unless it is posted as 1733(a) and 43 CFR 8360.0–7, or both. In shell, which is generally recognized as allowed, target shoot with a weapon within accordance with 43 CFR 8365.1–7, State or particularly suitable for sporting purposes.
    [Show full text]
  • Preserving Wild California an External Assessment
    PRESERVING WILD CALIFORNIA AN EXTERNAL ASSESSMENT Report to the Resources Legacy Fund Foundation Steven L. Yaffee, Sheila K. Schueller and Julia M. Wondolleck School of Natural Resources and Environment University of Michigan Ann Arbor, Michigan April 15, 2009 The authors gratefully acknowledge the valuable inputs of numerous Preserving Wild California staff and grantees along with others in the California conservation community who shared their experiences and insights with us. Research Team Steven L. Yaffee, PhD Sheila K. Schueller, PhD Julia M. Wondolleck, PhD Michelle S. Aldridge Yvette C. Dimcheff Nicole A. Fernandes Aviva Y. Glaser José G. Gonzalez Kristen E. Johnson Lauren V. Pidot For comments and questions, please contact: Dr. Steven Yaffee School of Natural Resources and Environment University of Michigan 440 Church Street Ann Arbor MI 48109‐1041 [email protected] 734‐763‐5451 Title page photos by Tupper Ansel Blake Table of Contents Executive Summary ……..............................................................…………………………………… ix Section 1 – Introduction and Method of Assessment ………………………………………… 1 The Bottom Line ………………………………………………………………………...... 1 Methods Used to Carry Out the External Assessment …………………………................. 3 Some Caveats …………………………………………………………………………...…. 7 A Roadmap to the Report ………………………………………………………………...... 9 Section 2 – What was Intended? The Logic of the PWC Program ……………………..… 11 An Ambitious but Clear Set of Goals and Objectives ………………………………...…… 12 Six Major Types of Grantmaking Strategies …………………………………………….… 14 A Set of Quantitative and Qualitative Measures of Success ………………………….…… 16 Section 3 – What was Funded? A Snapshot of Program Activities ………………….….. 23 How were funds distributed by region? ………………………………………………….… 25 How were funds distributed by type of project? ………………………………………….... 25 How were funds distributed by region and type of project? ………………………….……. 26 How many acres were acquired? ………………………………………………………….
    [Show full text]
  • National Landscape Conservation System: Wilderness Areas
    National Landscape Conservation System: Wilderness Areas State Field Office Wilderness Public Law Date Designated Units Acres AZ Gila District Aravaipa Canyon PL 101-628 8/28/1984 1 19,410 AZ Colorado River District Arrastra Mountain PL 101-628 11/28/1990 1 129,800 AZ Colorado River District Aubrey Peak PL 101-628 11/28/1990 1 15,400 AZ Gila District Baboquivari Peak PL 101-628 11/28/1990 1 2,040 AZ Arizona Strip District Beaver Dam Mountains (3,667 in UT) PL 98-406 8/28/1984 1 15,000 AZ Phoenix District Big Horn Mountains PL 101-628 11/28/1990 1 21,000 AZ Arizona Strip District Cottonwood Point PL 98-406 8/28/1984 1 6,860 AZ Gila District Coyote Mountains PL 101-628 11/28/1990 1 5,100 AZ Gila District Dos Cabezas Mountains PL 101-628 11/28/1990 1 11,700 AZ Colorado River District Eagletail Mountains PL 101-628 11/28/1990 1 97,880 AZ Colorado River District East Cactus Plain PL 101-628 11/28/1990 1 14,630 AZ Gila District Fishhooks PL 101-628 11/28/1990 1 10,500 AZ Colorado River District Gibralter Mountain PL 101-628 11/28/1990 1 18,790 AZ Arizona Strip District Grand Wash Cliffs PL 98-406 8/28/1984 1 37,030 AZ Colorado River District Harcuvar Mountains PL 101-628 11/28/1990 1 25,050 AZ Phoenix District Harquahala Mountains PL 101-628 11/28/1990 1 22,880 AZ Phoenix District Hassayampa River Canyon PL 101-628 11/28/1990 1 12,300 AZ Phoenix District Hells Canyon PL 101-628 11/28/1990 1 9,951 AZ Phoenix District Hummingbird Springs PL 101-628 11/28/1990 1 31,200 AZ Arizona Strip District Kanab Creek PL 98-406 8/28/1984 1 6,700 AZ Arizona
    [Show full text]
  • 2021-00579.Pdf (Federalregister.Gov)
    This document is scheduled to be published in the Federal Register on 01/14/2021 and available online at federalregister.gov/d/2021-00579, and on govinfo.gov 4310-40 DEPARTMENT OF THE INTERIOR Bureau of Land Management [(LLCA930000.L13400000.DS0000.21X) MO#450014117] Notice of Availability of the Draft Desert Plan Amendment and Draft Environmental Impact Statement, California AGENCY: Bureau of Land Management, Interior. ACTION: Notice of availability. SUMMARY: In accordance with the National Environmental Policy Act of 1969, as amended, the Bureau of Land Management (BLM) has prepared a Draft Land Use Plan Amendment (LUPA) and Draft Environmental Impact Statement (EIS), for an amendment to the California Desert Conservation Area (CDCA) Plan and the Bakersfield and Bishop Resource Management Plans (RMPs). The Desert Plan Amendment Draft LUPA/EIS includes consideration of changes to the management or modification to the boundaries of 129 Areas of Critical Environmental Concern (ACECs). By this notice, the BLM is announcing the availability of the Draft LUPA/EIS. In order to comply with Federal regulations, the BLM is also announcing a comment period on proposed changes to the ACECs within the planning area. DATES: To ensure that comments will be considered, the BLM must receive written comments on the Draft LUPA/ EIS within 90 days following the date the Environmental Protection Agency publishes its notice of the Draft LUPA/EIS in the Federal Register. The BLM will announce future meetings and any other public participation activities at least 15 days in advance through public notices, news releases, and/or mailings. ADDRESSES: The Desert Plan Amendment Draft LUPA/EIS are available on the BLM ePlanning project website at https://go.usa.gov/x7hdj.
    [Show full text]
  • Arizona Heritage Trail System Draft Environmental Assessment LC-16-14
    Arizona Heritage Trail System Draft Environmental Assessment LC-16-14 Lower Colorado Region, Boulder City, NV U.S. Department of the Interior Bureau of Reclamation National Park Service April 2017 Boulder City, NV Arizona Heritage Trail Draft EA LC-16-14 Mission Statements The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian Tribes and our commitments to island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. The National Park Service preserves unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations. The Park Service cooperates with partners to extend the benefits of natural and cultural resource conservation and outdoor recreation throughout this country and the world. Cover Photo: Looking south towards Bullhead City and Laughlin from proposed Heritage Trail System segment south of Davis Camp entrance. Arizona Heritage Trail Draft EA LC-16-14 Contents Table of Contents 1.0 Introduction and Purpose and Need ........................................................................................ 1 1.1 Background for the Purpose and Need .......................................................................... 1 1.2 Purpose and Need ..........................................................................................................
    [Show full text]