DOCSLIB.ORG

Geological Society of America Bulletin

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geological Society of America Bulletin Downloaded from gsabulletin.gsapubs.org on January 15, 2010 Geological Society of America Bulletin Early Pleistocene initiation of the San Felipe fault zone, SW Salton Trough, during reorganization of the San Andreas fault system Alexander N. Steely, Susanne U. Janecke, Rebecca J. Dorsey and Gary J. Axen Geological Society of America Bulletin 2009;121;663-687 doi: 10.1130/B26239.1 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Bulletin Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes © 2009 Geological Society of America Downloaded from gsabulletin.gsapubs.org on January 15, 2010 Early Pleistocene initiation of the San Felipe fault zone, SW Salton Trough, during reorganization of the San Andreas fault system Alexander N. Steely* Susanne U. Janecke† Department of Geology, Utah State University, Logan, Utah 84322-4505 Rebecca J. Dorsey Department of Geological Sciences, University of Oregon, Eugene, Oregon 97405, USA Gary J. Axen Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA ABSTRACT sorted angular boulder conglomerate and transtension to distributed dextral faulting pebbly sandstone of the Sunset Conglom- south of the Big Bend. Structural and stratigraphic analyses erate are ~600 m thick and lie in angular along the western margin of the Salton unconformity on the Pliocene Palm Spring Keywords: strike-slip fault, Ocotillo Forma- Trough show that the San Andreas fault sys- Group. The conglomerate coarsens upward tion, contractional step, reorganization, detach- tem was reorganized in early Pleistocene time and toward the fault, and is dominated by ment fault. from a system dominated by two fault zones plutonic clasts derived from SW of it. Con- (the San Andreas fault and the West Salton glomerate beds contain up to 10% sandstone INTRODUCTION detachment fault) to a network of dextral clasts recycled from older basin fi ll and accu- faults that include the San Andreas and at mulated in proximal to medial alluvial fans Rocks and structures in the Salton Trough least four dextral faults to the southwest. The that were shed to the NE from uplifted rocks contain a record of complex late Cenozoic San Felipe fault zone, one of these dextral along the then-active Sunset fault. deformation and sedimentation related to the faults, has ~5.8 ± 2.8 km of right separation Based on lithologic, stratigraphic, struc- evolution of the Pacifi c–North America plate and consists of three principal faults in the tural, and compositional similarities, we cor- boundary in southern California and northern Peninsular Ranges. These are the San Felipe relate the Sunset Conglomerate to the Pleis- Mexico (Fig. 1) (Dibblee, 1954; Atwater, 1970; fault in the WNW, Sunset fault in the middle, tocene Ocotillo Formation. Clasts of recycled Sharp, 1972; Crowell, 1981; Winker, 1987; and Fish Creek Mountains fault in the ESE. sandstone record erosion of detachment- Winker and Kidwell, 1986, 1996; Axen and They form a left-stepping array and bound related basin fi ll that predates the San Felipe Fletcher, 1998; Dorsey, 2006; Steely, 2006). domains in which the Sunset Conglomer- fault and once covered the Vallecito and Fish During late Miocene (?) and Pliocene time the ate, the older West Salton detachment fault, Creek mountains. These crystalline-cored West Salton detachment fault was a major struc- and Cretaceous mylonitic rocks below the mountain ranges fi rst emerged from beneath ture that produced the Salton supradetachment detachment are folded about WNW-trending basin fi ll during early slip above the nascent basin in its hanging wall (Axen and Fletcher, folds. A complex fl ower structure within the San Felipe fault ca. 1.1–1.3 Ma. Later, the 1998; Dorsey, 2006). The detachment probably left-stepovers probably produced this fault- San Felipe fault zone cut upward, folded, continued to slip into the early Pleistocene based parallel folding. Because all the rocks within cut across, and deactivated the West Salton on the presence of lower Pleistocene conglom- stepovers of the San Felipe fault zone, from detachment fault within a ~9-km-wide con- erate and megabreccia shed from its footwall Cretaceous to Pleistocene, are deformed tractional bend and pair of left-steps. Areas (Axen and Fletcher, 1998; Winker and Kidwell, about WNW-trending folds and record that accumulated sediment within this step- 2002; Dorsey and Janecke, 2002; Dorsey et al., broadly similar shortening strains, we infer a over zone between ca. 1.1 and ca. 0.6 Ma are 2006; Kairouz, 2005). Plate boundary strain Quaternary age of deformation. Parts of the currently being inverted and folded. during this time was divided between the mas- San Felipe fault zone cut latest Pleistocene Initiation of the San Felipe fault in early ter southern San Andreas fault and the second- to Holocene surfi cial deposits, and the fault Pleistocene time was a signifi cant event in the ary West Salton detachment fault (Axen and zone is likely active. reorganization of the southern San Andreas Fletcher, 1998). Beginning sometime in Pleis- Evidence for early Pleistocene initiation fault system. The Quaternary dextral faults tocene time, the relatively simple two-fault zone of the San Felipe fault zone is preserved in broadened the plate boundary zone south- system was replaced by a more complex system conglomerate NE of the Sunset fault. Poorly westward from roughly 25 km (during coeval in which roughly half of the strain was distrib- slip on the San Andreas fault and West Salton uted unevenly across new dextral-oblique faults *E-mail: [email protected] detachment fault) to 50–70 km, and mark a south of the Big Bend in the San Andreas fault †E-mail: [email protected] change in the dominant structural style from (Morton and Matti, 1993). This incompletely GSA Bulletin; May/June 2009; v. 121; no. 5/6; p. 663–687; doi: 10.1130/B26239.1; 15 fi gures; 1 table. For permission to copy, contact [email protected] 663 © 2009 Geological Society of America Downloaded from gsabulletin.gsapubs.org on January 15, 2010 Steely et al. To better understand the timing and structural style of this major tectonic reorganization along 34°N the plate boundary, we characterize and date the transition from slip on the West Salton detach- SAFZ Combin Palm Springs Y ment fault to slip on the San Felipe fault zone SJFZ in the western Salton Trough (Figs. 1 and 2). We examined exposures near Yaqui Ridge at the SFFZ SW margin of the San Felipe–Borrego subba- BSZ WSD sin to constrain the stratigraphic and structural ? EF Salton evolution of these structures (Fig. 3). Geologic 33°N mapping over an area of ~2.5 U.S. Geological Trough Survey (USGS) 7.5′ quadrangles was carried IF San Diego Gila R. out at scales of 1:12,000 and 1:24,000 in the Borrego Mountain, Borrego Sink, Harper Can- Col. R. yon, Whale Peak, and Squaw Peak 7.5′ USGS U.S.A. Mexico quadrangles (Steely, 2006). Stratigraphic, sedi- mentologic, and structural analyses reported km here are condensed from Steely (2006). 32°N 0 50 100 Regional Geology N The San Felipe fault zone strikes WNW and Gulf of is oriented ~10°–20° counterclockwise from the California 117°W 116°W 115°W 114°W adjacent San Jacinto and Elsinore fault zones. It is a major dextral strike-slip fault that approaches Figure 1. Tectonic overview of southern California and northern Mexico. San Felipe the Elsinore fault zone in the WNW and projects fault zone (SFFZ) is in bold black; other strike-slip faults are in black; SAFZ—San toward the Superstition Mountain segment of Andreas fault zone; SJFZ—San Jacinto fault zone; IF—Imperial fault; SJFZ—San the San Jacinto fault zone to the ESE (Dibblee, Jacinto fault zone; EF—Elsinore fault; BSZ—Brawley Seismic Zone. Oblique-slip 1954; Rogers, 1965; Figs. 1 and 2). The San detachment faults are in white including the WSD—West Salton detachment fault. Felipe and Elsinore fault zones were previously Fault locations are from Jennings (1977) and Axen and Fletcher (1998). Modifi ed inferred to have initiated by or before ca. 2 Ma from Kirby et al. (2007). Box is approximate location of Figure 2. in the Peninsular Ranges, with little signifi cant slip since ca. 0.9 Ma (Lamar and Rockwell, 1986; Hull and Nicholson, 1992; Magistrale and Rockwell, 1996). However, recent work understood event disrupted and deactivated ton detachment fault, as Lutz et al. (2006) and in the adjacent San Felipe Hills (Kirby, 2005; most of the West Salton detachment fault, reor- Kirby et al. (2007) proposed? What was the Kirby et al., 2007) and Borrego Badlands (Lutz, ganized the San Andreas fault system, and after basinal response to the growing San Felipe fault 2005; Lutz et al., 2006) documents a major some additional modifi cations, resulted in the zone? Is the San Felipe fault zone currently inac- stratigraphic and structural reorganization at current fault system of southern California.
Load more

Recommended publications
  • Geology of Hawk Canyon, Anza-Borrego Desert State Park, California
    GEOLOGY OF HAWK CANYON, ANZA-BORREGO DESERT STATE PARK, CALIFORNIA By Jeffrey D. Pepin Geological Sciences Department California State Polytechnic University Pomona, California 2011 Senior Thesis Submitted in partial fulfillment of the requirements for the Bachelor of Science Geology Degree Table of Contents Abstract ...............................................................................................................................1 Introduction ........................................................................................................................2 Purpose and Objectives ....................................................................................................2 Regional Geology .............................................................................................................4 Field Site Description .......................................................................................................9 Discussion of Previous Work Done in Hawk Canyon ...................................................11 Observational Data ..........................................................................................................12 Field Techniques ............................................................................................................12 Global Positioning System (GPS) Data and Notes ........................................................14 Orientation Data by Structure ........................................................................................20 Lithology ........................................................................................................................21
    [Show full text]
  • Anza-Borrego Desert State Park Bibliography Compiled and Edited by Jim Dice
    Steele/Burnand Anza-Borrego Desert Research Center University of California, Irvine UCI – NATURE and UC Natural Reserve System California State Parks – Colorado Desert District Anza-Borrego Desert State Park & Anza-Borrego Foundation Anza-Borrego Desert State Park Bibliography Compiled and Edited by Jim Dice (revised 1/31/2019) A gaggle of geneticists in Borrego Palm Canyon – 1975. (L-R, Dr. Theodosius Dobzhansky, Dr. Steve Bryant, Dr. Richard Lewontin, Dr. Steve Jones, Dr. TimEDITOR’S Prout. Photo NOTE by Dr. John Moore, courtesy of Steve Jones) Editor’s Note The publications cited in this volume specifically mention and/or discuss Anza-Borrego Desert State Park, locations and/or features known to occur within the present-day boundaries of Anza-Borrego Desert State Park, biological, geological, paleontological or anthropological specimens collected from localities within the present-day boundaries of Anza-Borrego Desert State Park, or events that have occurred within those same boundaries. This compendium is not now, nor will it ever be complete (barring, of course, the end of the Earth or the Park). Many, many people have helped to corral the references contained herein (see below). Any errors of omission and comission are the fault of the editor – who would be grateful to have such errors and omissions pointed out! [[email protected]] ACKNOWLEDGEMENTS As mentioned above, many many people have contributed to building this database of knowledge about Anza-Borrego Desert State Park. A quantum leap was taken somewhere in 2016-17 when Kevin Browne introduced me to Google Scholar – and we were off to the races. Elaine Tulving deserves a special mention for her assistance in dealing with formatting issues, keeping printers working, filing hard copies, ignoring occasional foul language – occasionally falling prey to it herself, and occasionally livening things up with an exclamation of “oh come on now, you just made that word up!” Bob Theriault assisted in many ways and now has a lifetime job, if he wants it, entering these references into Zotero.
    [Show full text]
  • Southern Exposures
    Searching for the Pliocene: Southern Exposures Robert E. Reynolds, editor California State University Desert Studies Center The 2012 Desert Research Symposium April 2012 Table of contents Searching for the Pliocene: Field trip guide to the southern exposures Field trip day 1 ���������������������������������������������������������������������������������������������������������������������������������������������� 5 Robert E. Reynolds, editor Field trip day 2 �������������������������������������������������������������������������������������������������������������������������������������������� 19 George T. Jefferson, David Lynch, L. K. Murray, and R. E. Reynolds Basin thickness variations at the junction of the Eastern California Shear Zone and the San Bernardino Mountains, California: how thick could the Pliocene section be? ��������������������������������������������������������������� 31 Victoria Langenheim, Tammy L. Surko, Phillip A. Armstrong, Jonathan C. Matti The morphology and anatomy of a Miocene long-runout landslide, Old Dad Mountain, California: implications for rock avalanche mechanics �������������������������������������������������������������������������������������������������� 38 Kim M. Bishop The discovery of the California Blue Mine ��������������������������������������������������������������������������������������������������� 44 Rick Kennedy Geomorphic evolution of the Morongo Valley, California ���������������������������������������������������������������������������� 45 Frank Jordan, Jr. New records
    [Show full text]
  • The Early Utilization and the Distribution of Agave in The
    University of New Mexico UNM Digital Repository UNM Bulletins Scholarly Communication - Departments 1938 The ae rly utilization and the distribution of agave in the American southwest Edward Franklin Castetter Willis Harvey Bell Alvin Russell Grove Follow this and additional works at: https://digitalrepository.unm.edu/unm_bulletin Recommended Citation Castetter, Edward Franklin; Willis Harvey Bell; and Alvin Russell Grove. "The ae rly utilization and the distribution of agave in the American southwest." University of New Mexico biological series, v. 5, no. 4, University of New Mexico bulletin, whole no. 335, Ethnobiological studies in the American Southwest, 6 5, 4 (1938). https://digitalrepository.unm.edu/unm_bulletin/31 This Article is brought to you for free and open access by the Scholarly Communication - Departments at UNM Digital Repository. It has been accepted for inclusion in UNM Bulletins by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. hlliig4 The University olNewMexico Bulletin 1 Ethnobiolbgical Studies in the American SouthweSt VI. \The Early Utilization and the Diftribution ofAgave in the American Southweft EDWARD F. CASTETTER, WILLIS H. BELL and ALVIN R. GROVE • .~ ~ r v~r4..f.2.,,",,~- A , ,-' "W'/ I))j j'A1' WJl\( ;JJ;,£~/:(Jcu~~/ HI" I' ~~fi!:~~e . M>rX~;;fre~ UNIVERSITY OF NEW ...//f ':iT' 1938 . Price 50 cents .':.W\~) e.s<:-f1} Qr~: rvJrl The University of New Mexico Vl5 . ,r Bulletin ~('J I 'j"' Ethnobiological Studies In the American Southwest VI. The Early Uttlization and the Distribution ofAgave in the American Southrzvest By EDWARD F. CASTETTER WILLIS H. BELL ALVIN R. GROVE THE UNIVERSITY OF NEW MEXICO BULLETIN Whole Number 335 December 1, 1938 Biological Series, Vol.
    [Show full text]
  • Genetic Origins and Population Status of Desert Tortoises in Anza-Borrego Desert State Park, California: Initial Steps Towards Population Monitoring
    G ENETIC ORIGINS AND POPULATION STATUS OF DESERT TORTOISES IN A NZA-BORREGO DESERT STATE PARK, CALIFORNIA: INITIAL STEPS TOWARDS POPULATION MONITORING Jeffrey A. Manning, Ph.D. Environmental Scientist California Department of Parks and Recreation Colorado Desert District 200 Palm Canyon Drive Borrego Springs, California 92004 November 2018 Manning, J.A. 2018. Genetic origins and population status of desert tortoises in Anza-Borrego Desert State Park, California: initial steps towards population monitoring. California Department of Parks and Recreation, Colorado Desert District, Borrego Springs, California. 89 pages. i Genetic Origins and Population Status of Desert Tortoises in Anza-Borrego Desert State Park, California: Initial Steps Towards Population Monitoring Final Report Jeffrey A. Manning, Ph.D., Author / Principle Investigator California Department of Parks and Recreation Colorado Desert District 200 Palm Canyon Drive Borrego Springs, California 92004 November 2018 Manning, J.A. 201 8. Genetic origins and population status of desert tortoises in Anza-Borrego Desert State Park, California: initial steps towards population monitoring. California Department of Parks and Recreation, Colorado Desert District, Borrego Springs, California. 89 pages. i FOREWORD The Desert tortoise (Gopherus sp.) was formally reported to science in 1861, and became the official California state reptile in 1972. Recent studies reveal three species, the Mojave desert tortoise (G. agassizii), Sonoran Desert tortoise (G. morafkai), and Sinaloan desert tortoise (G. evgoodei) (Murphy et al. 2011, Edwards et al. 2016; Figure 1). Range-wide declines in the Mojave desert tortoise population led California to prohibit the collection of this species in 1961. Despite this, it was emergency listed as federally endangered and state listed as threatened in 1989, and subsequently listed as federally threatened in 1990 (Federal Register 55, No 63, 50 CFR Part 17).
    [Show full text]
  • Water Resources of Borrego Valley, San Diego County, CA
    WATER RESOURCES OF BORREGO VALLEY SAN DIEGO COUNTY, CALIFORNIA _____________ A Thesis Presented to the Faculty of San Diego State University _____________ In Partial Fulfillment of the Requirements for the Degree Master of Science in Geological Sciences _____________ by Steven Paul Netto Fall 2001 iii Copyright 2001 by Steven Paul Netto iv ACKNOWLEDGMENTS First and foremost I would like to thank my wife Patti. She has sacrificed much over the years while supporting me in so many ways that I cannot find words adequate to express the gratitude that I feel. She has always been there for me and has carried more than her share as I have been occupied with coursework and this thesis effort, while at many times postponing or altogether foregoing her own interests. To my parents, Arnold and Velma Netto, I owe so many thanks. They have frequently expressed their interest, support and encouragement, and from them I have experienced the deepest kindness and generosity. Inspiring words from my father have stuck with me while finishing this thesis, he reminded me that it would take a lot of tenacity, not just know how, to finally get it done. And to my mother, Joan Fordyce, I also owe a debt of gratitude, for always being there with her love, support and enthusiasm. I am very fortunate to have had the opportunity to work with Dr. David Huntley on this project. It has been an enlightening experience for me and I have learned much from him that I will carry with me throughout the rest of my career.
    [Show full text]
  • A . INTRODUCTION B . PURPOSE C. STUDY AREA USER NOTES for SALTON SEA REGION SANTA ANA NE (32 Quads)
    USER NOTES FOR SALTON SEA REGION SANTA ANA NE (32 quads) SAt'TON- EArNW (;1 quad) SANTA ANA SE (2 quads) SALTON Sbr 9W.(32 o, "uuads' EL CENTRO NW (24 quads) NATIONAL WETLAND INVENTORY MAPS A . INTRODUCTION The U .S . Fish & Wildlife Service's National Wetlands Inventory is producing maps showing the location and classification of wetlands and deepwater habitats of the United States . The Classification of Wetlands and Deepwater Habitats of the United States by Cowardin et al . is the classification system used to define and classify wetlands . Photo interpretation conventions, hydric soils lists and wetland plant lists are also available to enhance the use and application of the classification system . B . PURPOSE The purpose of the notes to users is threefold : (1) to provide localized information regarding the production of NWI maps, including specific imagery and interpretation discussion ; (2) to provide a descriptive crosswalk from wetland codes on the map to common names and representative plant species, and (3) to explain local geography, climate, and wetland communities . C . STUDY AREA Geography : The Salton Trough is located in southern California . This study area is composed of five different maps ; Santa Ana NE, SE, Salton Sea NW, SW and El Centro NW (see index map) . This area is situated within two ecoregion provinces ; the American Desert Province and the California Chaparral Province (Bailey 1980) . The California Chaparral Province (no sections) borders the entire valley on the southwest side, from Santa Ar,a NE to El Centro NW . This province is characterized by the Coast Mountain Range which have steep unstable slopes, sharp crests and narrow valleys .
    [Show full text]
  • Peninsular Bighorn Sheep 2016-17 Annual Report
    CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE PENINSULAR BIGHORN SHEEP 2016-17 ANNUAL REPORT Photo By Jeff Young This report presents information on the status, distribution, and management of peninsular bighorn sheep from 1 January 2016 to 31 May 2017 Authors Janene Colby and Randy Botta South Coast Region California Department of Fish and Wildlife Peninsular Bighorn Sheep Annual Report 2016-17 Table of Contents Executive Summary……………………………………………….....1 Background……………………………………………………….........3 Population Size and Estimation………………………….……..3 Radio-Collar Status………………………………………………...…5 Cause-Specific Mortality and Survival………………………..5 Lamb Survival and Recruitment……………………………….10 Distribution and Movement…………………………………….12 San Jacinto Mountains………………………………..…….…...12 Northern Santa Rosa Mountains…………………...…...12 Central Santa Rosa Mountains………………………...........13 Southern Santa Rosa Mountains………………………....... 14 Coyote Canyon……….………………………………………........15 Northern San Ysidro Mountains…………………...….…15 Southern San Ysidro Mountains……………..…….…….16 Vallecito Mountains…………..………………………….…...17 Carrizo Canyon…………………………………………….….….18 Threats to Recovery…………………………………….……..…..19 San Jacinto Mountains…………………………..................19 Northern Santa Rosa Mountains……………………………....19 Central Santa Rosa Mountains………………….……....…..19 Southern Santa Rosa Mountains…………………….…...…21 Coyote Canyon…………………………………………….….…...21 Northern San Ysidro Mountains…………………..….……..22 Southern San Ysidro Mountains……………………….…....22 Vallecito Mountains…………………………………………..….22 Carrizo Canyon……………………………………………..….…..23
    [Show full text]
  • Warbler, Yellow-Rumped
    Wood Warblers — Family Parulidae 477 Yellow-rumped Warbler Dendroica coronata The Yellow-rumped Warbler is probably San Diego County’s most abundant winter visitor. If the White- crowned Sparrow exceeds it, it is not by much. Eucalyptus groves and other exotic trees planted in developed areas suit the Yellow-rumped Warbler at least as much as natural sage scrub, chaparral, and woodland. The birds are strongly concentrated in the coastal lowland but are found almost through- out the county, lacking only from the most rugged parts of the Anza–Borrego Desert. As a breeding species, however, the Yellow-rumped Warbler is a recent colonist, rare and confined to coniferous Photo by Anthony Mercieca forest on San Diego County’s highest mountains. Because almost all Yellow-rumped Warblers are readily distin- guished in the field as belong- ing to either the eastern or the western group of subspecies, and the status of each is so different, this account refers to them by their traditional names, Audubon’s Warbler for the yellow-throated western birds, Myrtle Warbler for the white-throated eastern ones. See under Taxonomy for the status of the Myrtle. Winter: San Diego County must be near the core of the Audubon’s Warbler’s winter range. The spe- cies is common to abundant 478 Wood Warblers — Family Parulidae Breeding distribution: Audu- bon’s Warbler is another of those birds, like the Fox Sparrow, Green-tailed Towhee, and Dusky Flycatcher, whose breeding habi- tat lies in an elevation zone bare- ly pierced by San Diego County’s highest peaks. The warblers are now of annual occurrence in the Cuyamaca Mountains, with up to eight, including five singing males, on Middle Peak (M20) 11 June 2000 (R.
    [Show full text]
  • Recovery Plan for Bighorn Sheep in the Peninsular Ranges, California
    u.s. Fish & Wildlife Service Recovery Plan for Bighorn Sheep in the Peninsular Ranges, California 010753 010208 Recovery Plan for Bighorn Sheep in the Peninsular Ranges, California U.S. Fish and Wildlife Service Region 1 Approved: Manager, C ia/Nevada Operations Office Region , U.S. Fish and Wildlife Service Date: 010754 010210 The Recovery Plan for Bighorn Sheep in the Peninsular Ranges, California, was developed in cooperation with: Bureau ofLand Management U.S. Forest Service Agua Caliente Band ofCahuilla Indians California Department of Fish and Game California Department ofParks and Recreation Date: ~ Date: IQ41.7./L2Q. Tnbal Chairman, Agua Caliente Band of Cahuilla Indians Date: /Pz— 00 Ii.Director. Ca fornia Department Fish and Game _ Date: __________ Director, California Dep yent of Parks and Recrcation 010755 010211 Primary Author The primary author of this recovery plan is: Esther Rubin University of California, Davis Davis, California The plan was written with the assistance ofthe Peninsular Bighom Sheep Recovery Team (see Acknowledgments). i 010756 010212 Disclaimer Recovery plans delineate reasonable actions required to recover andlor protect listed species. We, the Fish and Wildlife Service, publish recovery plans, sometimes preparing them with the assistance of recovery teams, contractors, State and other Federal agencies, Tribes, and other affected and interested parties. Recovery teams serve as independent advisors to the Fish and Wildlife Service. Objectives ofthe plan will be attained and any necessary funds made available, subject to budgetary and other constraints affecting the parties involved. Recovery plans do not obligate cooperating or other parties to undertake specific tasks and may not represent the views nor the official positions or approval ofany individuals or agencies involved in the plan formulation, other than our own.
    [Show full text]
  • California Department of Fish and Wildlife Peninsular Bighorn Sheep Annual Report 2015
    CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE PENINSULAR BIGHORN SHEEP 2015 ANNUAL REPORT A cooperative effort by the California Department of Fish and Wildlife, U.S. Fish and Wildlife Service, and California Department of Parks and Recreation Photo by Janene Colby This report presents information on the status, distribution, and management of peninsular bighorn sheep in eastern San Diego County and portions of Riverside and Imperial Counties for 2015 Authors Janene Colby and Randy Botta South Coast Region California Department of Fish and Wildlife Peninsular Bighorn Sheep Annual Report 2015 Table of Contents Executive Summary………………………………………………...1 Background……………………………………………………….......3 Capture and Radio-collaring……………………………………3 Radio Collar Status………………………………………………….4 Population Size and Estimation…………………….………..5 Respiratory Disease………………………………………………..5 Cause Specific Mortality and Survival……………………..6 Lamb Survival and Recruitment……………………………...8 Distribution and Movement………………………………….11 San Jacinto Mountains………………………………………...12 Central Santa Rosa Mountains………………………........12 Southern Santa Rosa Mountains……………………….....15 Vallecito Mountains………………………………………......16 Threats to Recovery………………………………………….….17 San Jacinto Mountains…………………………................17 Northern Santa Rosa Mountains………………………….17 Central Santa Rosa Mountains………………….……...…17 Southern Santa Rosa Mountains…………………….……19 Coyote Canyon…………………………………………….….…19 Northern San Ysidro Mountains………………….….…...19 Southern San Ysidro Mountains……………………..…...20 Vallecito Mountains……………………………………………20
    [Show full text]
  • Mason Valley Groundwater Basin Bulletin 118
    Hydrologic Region Colorado River California’s Groundwater Mason Valley Groundwater Basin Bulletin 118 Mason Valley Groundwater Basin • Groundwater Basin Number: 7-59 • County: San Diego • Surface Area: 5,530 acres (8.6 square miles) Basin Boundaries and Hydrology The Mason Valley Groundwater Basin underlies a southeast-trending valley in eastern San Diego County. Elevation of the valley floor ranges from about 2,500 to 3,000 feet above sea level. The basin is bounded by nonwater- bearing rocks of the Laguna Mountains on the west and northwest, of the Granite Mountains on the north, of the Vallecito Mountains on the east, and of the Sawtooth Range on the south and southeast. Maximum elevation in the surrounding mountains is 5,665 feet at Garnet Mountain in the Laguna Mountains (Strand 1962; Rogers 1965). Annual average precipitation ranges from about 12 to 20 inches. Mason Valley is drained by Vallecito Creek, which discharges eastward into Vallecito Valley (Brown 1923; Rogers 1965). Hydrogeologic Information Water Bearing Formations Groundwater is found in unconsolidated younger Quaternary alluvial deposits and underlying unconsolidated to semi-consolidated older Tertiary to Quaternary alluvial deposits (DWR 1954). Recharge and Discharge Areas Recharge of the basin is from surface and subsurface inflow from Vallecito Creek by way of Rodriguez Canyon on the northwest, from infiltration of runoff through course-grained alluvial deposits at the base of the surrounding mountains, and from percolation of precipitation that falls on the valley floor. Groundwater moves east and discharges as underflow of Vallecito Creek into the Vallecito-Carrizo Valley Groundwater Basin (Brown 1923; Rogers 1965).
    [Show full text]