DOCSLIB.ORG

Environmental Setting

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Chapter 2 Environmental Setting Table of Contents 2.1 Introduction ........................................................................................... 2-1 2.2 Land Use ................................................................................................ 2-2 2.2.1 Existing Conditions .......................................................................... 2-2 2.2.2 Land Use Categories ........................................................................ 2-3 2.2.3 Land Use Controls ........................................................................... 2-7 2.2.4 Open Space (Public Lands and Private Easements) ........................ 2-9 2.3 Physical Resources ............................................................................... 2-15 2.3.1 Location ......................................................................................... 2-15 2.3.2 Topography ................................................................................... 2-15 2.3.3 Geology and Soils .......................................................................... 2-16 2.3.4 Climate .......................................................................................... 2-19 2.3.5 Hydrology ...................................................................................... 2-21 2.4 Biological Resources ............................................................................ 2-23 2.4.1 Methods ........................................................................................ 2-23 2.4.2 Biological Diversity in the Study Area ........................................... 2-31 2.4.3 Natural Communities and Land Cover Types ................................ 2-32 2.4.4 Habitat Connectivity and Wildlife Linkages ................................... 2-76 2.1 Introduction This chapter describes the physical and biological resources within the study area that are relevant to the Conservation Strategy. This chapter includes a land use section that provides an overview of the major land use and open space management agencies operating within the study area. The physical resources section provides a characterization of the topography, geology and soils, climate, and hydrology of the study area. The biological resources section includes a discussion of biological diversity, natural communities, land cover types, and focal species in the study area. Together, the land use, physical resources, and biological resources sections provide the necessary context for the biological goals and objectives upon which Chapter 3, “Conservation Strategy,” is based. East Alameda County Conservation Strategy 2-1 October 2010 ICF 00906.08 Chapter 2 Environmental Setting 2.2 Land Use This section examines existing land use conditions and land use plans in east Alameda County. This section provides history and context for land use in the study area; reviews existing land use conditions and relevant land use plans; presents the criteria used to determine land use categories; and discusses significant existing open spaces in the study area and an open space type classification system. 2.2.1 Existing Conditions East Alameda County encompasses 271,485 acres (approximately 424 square miles) and represents 52% of Alameda County, which has a land area of 525,540 acres (approximately 821 square miles). Alameda County is located north of Santa Clara County, west of San Joaquin County, and south of Contra Costa County (see Figure 1-1 for the regional location of the study area). East Alameda County is situated east of the San Leandro Hills and Walpert Ridge (Corbett 2005). The cities of Dublin, Livermore, Pleasanton, a portion of the city of Hayward, and surrounding unincorporated areas are the major developed areas of east Alameda County (Alameda County Community Development Agency 2002). The cities of Dublin, Livermore, and Pleasanton are completely included in the study area. According to the most recent Census data, the population of east Alameda County is approximately 171,652, about 12% of the population of the entire county, which is 1,443,741 (U.S. Census Bureau 2000). In east Alameda County, Livermore has the most residents, with a population of 80,723(City of Livermore 2009); followed by Pleasanton, with a population of 68,755 (City of Pleasanton 2009a); and Dublin, with a population of 46,934 (City of Dublin 2009a). Located between the urban areas surrounding the San Francisco Bay and the Central Valley, east Alameda County has had considerable growth pressure in the recent past. In 1990, the population was approximately 133,000 and will most likely exceed 250,000 by 2010, representing an 88% growth (Alameda County Community Development Agency 2002). The Association of Bay Area Governments (ABAG) has projected that the populations of Livermore, Pleasanton, and Dublin will grow to 89,600; 75,300; and 56,800 by the year 2015, and 95,500; 79,100; and 62,700 by the year 2020, respectively (Association of Bay Area Governments 2006). Dublin was incorporated in 1982 (City of Dublin 2009b), Livermore was incorporated in 1876 (City of Livermore 2009), and Pleasanton was incorporated in 1894 (City of Pleasanton 2009a). Dublin was incorporated to accommodate the increasing demand for commercial and residential development in the area, and has experienced a more recent increase in growth compared to Livermore East Alameda County Conservation Strategy 2-2 October 2010 ICF 00906.08 Chapter 2 Environmental Setting and Pleasanton, which have grown steadily since incorporation (City of Dublin 2009b). Recent growth in the region and the subsequent impacts on residents’ quality of life are major concerns for the region (Alameda County Community Development Agency 2002). The County and Cities of Livermore, Pleasanton, and Dublin maintain a strong commitment to protecting the natural and agricultural resources within and surrounding their respective jurisdictions. Reflecting this vision, the County and Cities of Livermore and Pleasanton have each adopted an Urban Growth Boundary (UGB), while Dublin has adopted Planning Area Boundaries as an ultimate build-out line. More detail on the open space policies and UGBs is provided in Sections 2.2.4 and 2.2.3.1 below for each participating jurisdiction. 2.2.2 Land Use Categories Understanding the current land use patterns and potential future land uses in the study area were an important step in developing the strategy discussed in Chapter 3. This understanding, in conjunction with an assessment of the biological resources in the study area allowed for the development of a conservation strategy that is informed by the current land use patterns in the county. Furthermore, land use designations aid the process by informing agencies as to the areas that are currently protected, areas that are likely to be affected, and areas where conservation will need to occur. The general plans for the cities of Dublin, Livermore, and Pleasanton and Alameda County were used to identify the future extent and location of urban and rural development in the study area. Land use designations vary across jurisdictions and are in many more categories than necessary for conservation planning purposes, so the designations were simplified and standardized. The process by which a land use map was developed and how land use categories for the Conservation Strategy were assigned is described below. 2.2.2.1 Land Use Methodology Land use planning designations for Alameda County and the cities of Dublin, Livermore, and Pleasanton were used to develop a single land use map for the Conservation Strategy. Future land uses were assumed to be consistent with the County’s general and specific plans (East County Area Plan [2002]; South Livermore Valley Area Plan [adopted by Alameda County Board of Supervisors on February 3, 1993]); and the general plans for the City of Dublin [2008], City of Livermore [2004], and the City of Pleasanton [2009b]). The County’s general and specific plans project future land use to 2010, and the Dublin, Livermore, and Pleasanton general plans project future land use to 2025. Using these East Alameda County Conservation Strategy 2-3 October 2010 ICF 00906.08 Chapter 2 Environmental Setting projections for this strategy is appropriate given the strength of each jurisdiction’s commitment to constraining future growth within established UGBs (see Section 2.2.3 below for a discussion of local land use controls). One hundred five land use planning designations from the four land use authorities were aggregated into the following three simplified land use planning categories: Urban/Developed; Private agriculture, and/or Rangelands; and Public Lands. Development of these categories was guided by the nature of the potential activities that will require a discretionary permit within each land use category and their relative impact on biological resources. For example, the many urban land use categories (e.g., commercial, industrial, mixed use) were combined into a single land use category, “Urban/Developed,” because all of the land uses result in similar effects on biological resources. Table 2-1 shows general plan land uses and the land use categories to which they were converted for this strategy. Some land use designations were split into two or more of the land use categories for this strategy. 2.2.2.2 Generalized Land Use Categories Historically, agriculture has played a major role in the economy of Alameda County (Alameda County Community Development Department 2008). Agriculture continues to be an important part of
Recommended publications
  • Chapter 5: Parks, Recreation, and Open Space

    Chapter 5: Parks, Recreation, and Open Space

    5 Parks, Recreation, and Open Space This chapter is a guide to the parks, recreation and open space resources in Humboldt County. Humboldt is home to recreational, park, and open space resources of statewide, nationwide, and even global significance. With this in mind, the first two sections describe these resources, while the final section addresses existing policies and policy issues identified during Phase I along with policy options that respond to them. 5.1 PARK AND RECREATION FACILITIES Humboldt County has a wealth of outdoor recreational opportunities and areas of incomparable value and unsurpassed beauty. More than twenty percent of the county’s 2.3 million acres are protected open space, forests, and recreation areas. Within the county boundaries, there are 4 federal parks and beaches, 10 state parks (3 of which are encompassed by Redwood National Park), 16 county parks and beaches, recreational areas and reserves, and National Parkland and National Forest land. These areas contribute to the quality of life in Humboldt County and provide needed recreation opportunities for residents of neighboring counties and from all over the world as well. Parklands are important elements of the Humboldt economy through both their role in the timber industry and the tourist industry. As tourism eclipses timber as the stronghold of Humboldt’s economy, parks and recreational resources will prove of greater and greater value to Humboldt’s future. The natural qualities of Humboldt County attract a great many people from outside the county. The tourist industry and demand for park resources in Humboldt are linked to the accessibility of parkland.
  • Late Cenozoic Tectonics of the Central and Southern Coast Ranges of California

    Late Cenozoic Tectonics of the Central and Southern Coast Ranges of California

    OVERVIEW Late Cenozoic tectonics of the central and southern Coast Ranges of California Benjamin M. Page* Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115 George A. Thompson† Department of Geophysics, Stanford University, Stanford, California 94305-2215 Robert G. Coleman Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115 ABSTRACT within the Coast Ranges is ascribed in large Taliaferro (e.g., 1943). A prodigious amount of part to the well-established change in plate mo- geologic mapping by T. W. Dibblee, Jr., pre- The central and southern Coast Ranges tions at about 3.5 Ma. sented the areal geology in a form that made gen- of California coincide with the broad Pa- eral interpretations possible. E. H. Bailey, W. P. cific–North American plate boundary. The INTRODUCTION Irwin, D. L. Jones, M. C. Blake, and R. J. ranges formed during the transform regime, McLaughlin of the U.S. Geological Survey and but show little direct mechanical relation to The California Coast Ranges province encom- W. R. Dickinson are among many who have con- strike-slip faulting. After late Miocene defor- passes a system of elongate mountains and inter- tributed enormously to the present understanding mation, two recent generations of range build- vening valleys collectively extending southeast- of the Coast Ranges. Representative references ing occurred: (1) folding and thrusting, begin- ward from the latitude of Cape Mendocino (or by these and many other individuals were cited in ning ca. 3.5 Ma and increasing at 0.4 Ma, and beyond) to the Transverse Ranges. This paper Page (1981).
  • Geologic Gems of California's State Parks

    Geologic Gems of California's State Parks

    STATE OF CALIFORNIA – EDMUND G. BROWN JR., GOVERNOR NATURAL RESOURCES AGENCY – JOHN LAIRD, SECRETARY CALIFORNIA GEOLOGICAL SURVEY DEPARTMENT OF PARKS AND RECREATION – LISA MANGAT, DIRECTOR JOHN D. PARRISH, Ph.D., STATE GEOLOGIST DEPARTMENT OF CONSERVATION – DAVID BUNN, DIRECTOR PLATE 1 The rugged cliffs of Del Norte Coast Redwoods State Park are composed of some of California’s Bio-regions the most tortured, twisted, and mobile rocks of the North American continent. The California’s Geomorphic Provinces rocks are mostly buried beneath soils and covered by vigorous redwood forests, which thrive in a climate famous for summer fog and powerful winter storms. The rocks only reveal themselves in steep stream banks, along road and trail cut banks, along the precipitous coastal cliffs and offshore in the form of towering rock monuments or sea stacks. (Photograph by CalTrans staff.) Few of California’s State parks display impressive monoliths adorned like a Patrick’s Point State Park displays a snapshot of geologic processes that have castle with towering spires and few permit rock climbing. Castle Crags State shaped the face of western North America, and that continue today. The rocks Park is an exception. The scenic beauty is best enjoyed from a distant exposed in the seacliffs and offshore represent dynamic interplay between the vantage point where one can see the range of surrounding landforms. The The Klamath Mountains consist of several rugged ranges and deep canyons. Klamath/North Coast Bioregion San Joaquin Valley Colorado Desert subducting oceanic tectonic plate (Gorda Plate) and the continental North American monolith and its surroundings are a microcosm of the Klamath Mountains The mountains reach elevations of 6,000 to 8,000 feet.
  • 2010 Urban Water Management Plan

    2010 Urban Water Management Plan

    2010 URBAN WATER MANAGEMENT PLAN December 15, 2010 Zone 7 Water Agency Livermore, CA 2010 URBAN WATER MANAGEMENT PLAN Prepared by: Zone 7 Water Agency 100 North Canyons Parkway Livermore, CA 94551 (925) 454-5000 Version: December 15, 2010 ZONE 7 WATER AGENCY Report Contributors: Kurt Arends, P.E. – Assistant General Manager of Engineering Boni Brewer – Public Information Officer Jarnail Chahal, P.E. – Principal Engineer Jill Duerig, P.E. – General Manager Amparo Flores, P.E. – Associate Engineer JaVia Green – Staff Analyst Matt Katen, P.G. – Principal Engineer Brad Ledesma, P.E. – Associate Engineer Robyn Navarra – Water Conservation Coordinator Sal Segura, P.E. – Associate Engineer Vince Wong, P.E. - Assistant General Manager of Operations Report Contact: Amparo Flores, (925) 454-5019, [email protected] or Brad Ledesma, (925) 454-5038, [email protected] TABLE OF CONTENTS 1. Introduction ........................................................................................................................ 1-1 1.1 Previous Urban Water Management Plans ........................................................................ 1-1 1.2 The Purpose of the 2010 UWMP ....................................................................................... 1-1 1.3 Plan Contents and Organization......................................................................................... 1-2 1.4 Changes from the 2005 UWMP ......................................................................................... 1-2 2. General Service Area ........................................................................................................
  • Bigbig Sursur

    Bigbig Sursur

    CalCal PolyPoly -- PomonaPomona GeologyGeology ClubClub SpringSpring 20032003 FFieldield TTriprip BigBig SurSur David R. Jessey Randal E. Burns Leianna L. Michalka Danielle M. Wall ACKNOWLEDGEMENT The authors of this field guide would like to express their appreciation and sincere thanks to the Peninsula Geologic Society, the California Geological Survey and Caltrans. Without their excellent publications this guide would not have been possible. We apologize for any errors made through exclusion or addition of trip field stops. For more detailed descriptions please see the following: Zatkin, Robert (ed.), 2000, Salinia/Nacimiento Amalgamated Terrane Big Sur Coast, Central California, Peninsula Geological Society Spring Field Trip 2000 Guidebook, 214 p. Wills, C.J., Manson, M.W., Brown, K.D., Davenport, C.W. and Domrose, C.J., 2001, LANDSLIDES IN THE HIGHWAY 1 CORRIDOR: GEOLOGY AND SLOPE STABILITY ALONG THE BIG SUR COAST, California Department of Conservation Division of Mines & Geology, 43 p. 0 122 0 00' 122 0 45' 121 30 Qal Peninsula Geological Society Qal G a b i Qt la Field Trip to Salina/Nacimento 1 n R S a A n L Big Sur Coast, Central California I g N qd A e S R Qt IV E Salinas R S a lin a s Qs V Qal 101 a Qs Monterey Qc lle Qt Qp y pgm Tm Qm Seaside pgm EXPLANATION Qt Chualar Qp Qt UNCONSOLIDATED Tm pgm SEDIMENTS Qp Carmel Qal sur Qs Qal Alluvium qd CARMEL RIVER Tm Qal Point sur Qs Dune Sand Tm Lobos pgm 0 S 0 36 30 ie ' r 36 30' pgm ra Qt Quaternary non-marine d CARMEL e S terrace deposits VALLEY a Qal lin a Qt Pleistocene non-marine Tm pgm s Qc 1 Tm Tula qd rcit Qp Plio-Pleistocene non-marine qd os F ault Qm Pleistocene marine Terrace sur sur deposits qd Tm COVER ROCKS pgm qd Tm Monterey Formation, mostly qm pgm qm pgm marine biogenic and sur pgm clastic sediments middle to qdp sur qd late Miocene in age.
  • Development and Implications of a Sediment Budget for the Upper Elk River Watershed, Humboldt County1

    Development and Implications of a Sediment Budget for the Upper Elk River Watershed, Humboldt County1

    Proceedings of the Coast Redwood Science Symposium—2016 Development and Implications of a Sediment Budget for the Upper Elk River Watershed, Humboldt County1 2 3 3 3 Lee H. MacDonald, Michael W. Miles, Shane Beach, Nicolas M. Harrison, 4 5 6 Matthew R. House, Patrick Belmont, and Ken L. Ferrier Abstract A number of watersheds on the North Coast of California have been designated as sediment impaired under the Clean Water Act, including the 112 km2 upper Elk River watershed that flows into Humboldt Bay just south of Eureka. The objectives of this paper are to: 1) briefly explain the geomorphic context and anthropogenic uses of the Elk River watershed; 2) develop a process-based sediment budget for the upper watershed, including an explicit assessment of the uncertainties in each component; and 3) use the results to help guide future management and restoration. Natural (background) sediment inputs are believed to be relatively high due to high uplift rates, weak Miocene-Pliocene bedrock materials, steep slopes, high rainfall, and resulting high landslide frequency. The primary land use in the upper watershed is industrial timberlands, and intensive logging in the 1980s and 1990s greatly increased sediment production rates and downstream aggradation. Road improvements and major changes in forest practices have caused anthropogenic sediment inputs to drop by roughly an order of magnitude since the 1990s. Suspended sediment yields plotted against annual maximum peak flows indicate a decline since 2013, suggesting that the legacy pulse of sediment is now moving into the lower portions of the watershed and that improved management practices are having a beneficial effect.
  • Living with Fire in California's Coast Ranges

    Living with Fire in California's Coast Ranges

    SYMPOSIUM PROGRAM LIVING WITH FIRE IN CALIFORNIA’S COAST RANGES Promoting Fire-Resilient Communities and Landscapes in an Era of Global Change PHOTO CREDITS FROM LEFT TO RIGHT 1. COFFEY PARK, TUBBS FIRE - JOHN BURGESS 2. NUNS FIRE - KENT PORTER 3. POCKET FIRE - KENT PORTER MONDAY MAY 7 Setting the stage: Fire ecology and fire history of the Central and North Coast Ranges 08:30-08:50 1. Welcome, introduction, Sonoma State University welcome Hugh Safford, US Forest Service Pacific and agenda SW Region, Lenya Quinn-Davidson, UC-Cooperative Extension, and Lisa Vollendorf, SSU Provost 08:50-09:10 2. Fire ecology basics: a primer for northern California Lenya Quinn-Davidson, UC- communities Cooperative Extension 09:10-09:45 3. Fire ecology of the central and north Coast Ranges of Scott Stephens, UC-Berkeley California 09:45-10:15 4. Modern era fire history in the Central Coast Region: What Marshall Turbeville, CAL FIRE, the past can tell us about the future Sonoma-Lake-Napa Unit 10:15-10:35 Discussion 10:35-10:55 Break (coffee and tea provided) Understanding the Wine Country Fires 10:55-11:40 5. Fall 2017 Sonoma Fires: An operational perspective on Greg Bertelli, CAL FIRE, Sonoma-Lake- emergency response, tactics, and the modern Urban-Interface Napa Unit fire problem 11:40-12:10 Discussion 12:10-13:40 Lunch (Provided) Understanding the Wine Country Fires (cont) 13:40-14:10 6. Meteorology and weather associated with extreme wildfire Craig Clements, San Jose State in Coastal California University 14:10-14:40 7. Nexus between climate, weather and ignition sources: Jon Keeley, US Geological Survey Regional patterns in California 14:40-15:00 Discussion 15:00-15:20 Break Fire and humans 15:20-15:50 8.
  • United States Department of the Interior Geological Survey Geologic Map of the Las Positas, Greenville, and Verona Faults, Easte

    United States Department of the Interior Geological Survey Geologic Map of the Las Positas, Greenville, and Verona Faults, Easte

    UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY GEOLOGIC MAP OF THE LAS POSITAS, GREENVILLE, AND VERONA FAULTS, EASTERN ALAMEDA COUNTY, CALIFORNIA By DARRELL G, HERD Open-file report 77-689 INTRODUCTION Livermore Valley, a large east-trending valley in eastern Alameda County, California, approximately 50 kn east of San Francisco, is unique in the central Coast Ranges, where all other major valleys trend northwest* Bounded on the west and east by two major right-lateral strike-slip fault zones the Calaveras-Sunol and the Greenville, Liverraore Valley was originally believed to be crossed by other northwest-trending faults, inferred from ground-water level differences and geophysical anomalies (California Dept. Water Resources, 1963, 1966, 1974; Wight, 1974). Recent mapping in Liverraore Valley and surrounding areas (Herd, 1975) has revealed the existence of the Las Positas fault zone, a high-angle, northeast- trending fault zone that forms the southern limit of the valley and extends from La Costa Valley, east of the Calaveras-Sunol fault zone, northeastward to the Greenville fault zone. The Las Positas fault zone is the first reported northeast-trending fault zone in the central Coast Ranges of California with a history of Quaternary movement. Purpose of map This map depicts the geologic setting of the Las Positas and Greenville fault zones, which bound Livermore Valley on the south and east, and the Verona fault, which lies southwest of Liverraore Valley. The map presents a new interpretation of the geology of Livermore Valley and adjoining areas, and contains new subdivisions of the Quaternary stratigraphy. The recency and recurrence of displacements along the three faults is assessed and an interpretation of the tectonic setting of Livermore Valley proposed.
  • AT Dublin Project Water Supply Assessment

    AT Dublin Project Water Supply Assessment

    DUBLIN SAN RAMON SERVICES DISTRICT Board of Directors NOTICE OF REGULAR MEETING TIME: 6 p.m. DATE: Tuesday, February 20, 2018 PLACE: Regular Meeting Place 7051 Dublin Boulevard, Dublin, CA AGENDA Our mission is to provide reliable and sustainable water, recycled water, and wastewater services in a safe, efficient, and environmentally responsible manner. 1. CALL TO ORDER 2. PLEDGE TO THE FLAG 3. ROLL CALL – Members: Duarte, Halket, Howard, Misheloff, Vonheeder-Leopold 4. SPECIAL ANNOUNCEMENTS/ACTIVITIES 5. PUBLIC COMMENT (MEETING OPEN TO THE PUBLIC) At this time those in the audience are encouraged to address the Board on any item of interest that is within the subject matter jurisdiction of the Board and not already included on tonight’s agenda. Comments should not exceed five minutes. Speakers’ cards are available from the District Secretary and should be completed and returned to the Secretary prior to addressing the Board. The President of the Board will recognize each speaker, at which time the speaker should proceed to the lectern, introduce him/herself, and then proceed with his/her comment. 6. REPORTS 6.A. Reports by General Manager and Staff Event Calendar Correspondence to and from the Board 6.B. Joint Powers Authority and Committee Reports 6.C. Agenda Management (consider order of items) 7. APPROVAL OF MINUTES 7.A. Regular Meeting Minutes of February 6, 2018 Recommended Action: Approve by Motion 8. CONSENT CALENDAR Matters listed under this item are considered routine and will be enacted by one Motion, in the form listed below. There will be no separate discussion of these items unless requested by a Member of the Board of Directors or the public prior to the time the Board votes on the Motion to adopt.
  • MITIGATED NEGATIVE DECLARATION for the Tesla Road

    MITIGATED NEGATIVE DECLARATION for the Tesla Road

    Draft INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION for the Tesla Road Winery ALAMEDA COUNTY CALIFORNIA Prepared for: Alameda County CDA Planning Division Prepared by: Denise Duffy & Associates Contact: Denise Duffy 947 Cass St. Suite 5 Monterey, California 93940 July 31, 2015 This page left intentionally blank. MITIGATED NEGATIVE DECLARATION Project: Tesla Road Winery Lead Agency: Alameda County PROJECT DESCRIPTION This Mitigated Negative Declaration (MND), supported by the attached Initial Study (IS), evaluates the environmental effects of a proposed multi‐use wine facility at the northeast corner of the Greenville Road and Tesla Road intersection outside of Livermore, within unincorporated Alameda County, California. The applicant, RAO Company, is proposing the construction of a new 19,944 square foot (sq. ft.) building on the the property. The building’s primary function would be to provide space for wine tasting, tours, and special events, and administrative offices for employees. The building would provide a dedicated space to process wine, serve customers, and hold events. Alameda County is the lead agency for this project and has prepared this MND. FINDINGS An IS has been prepared to assess the projects potential effects on the environment and the significance of those effects. Based on the Initial Study, it has been determined that the proposed project would not have any significant effects on the environment once mitigation measures are implemented. This conclusion is supported by the following findings: 1. The proposed project would have no impact related to greenhouse gas emissions, aesthetics, agricultural resources, hazards/hazardous materials, land use/planning mineral resources, population/housing, public services, and recreation.
  • Chronology of Emplacement of Mesozoic Batholithic Complexes in California and Western Nevada by J

    Chronology of Emplacement of Mesozoic Batholithic Complexes in California and Western Nevada by J

    Chronology of Emplacement of Mesozoic Batholithic Complexes In California and Western Nevada By J. F. EVERNDEN and R. W. KISTLER GEOLOGICAL SURVEY PROFESSIONAL PAPER 623 Prepared in cooperation with the University of California (Berkeley) Department of Geological Sciences UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1970 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HICKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Con;gress CSJtalog-card No. 7s-.60.38'60 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1.25 (paper cover) CONTENTS Page Abstract-------------------------------~---------------------------------------------------------------------- 1 Introduction--------------------------------------------------------------------------------~----------------- 1 Analyt:cal problems ____________________ -._______________________________________________________________________ 2 Analytical procedures______________________________________________________________________________________ 2 Precision and accuracy ___________________ -.- __ _ _ _ _ __ _ _ _ __ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 Potassium determinations_______________________________________________________________________________ · 2 Argon determinations--------~------------------~------------------------------------------------------ 5 Chemical and crystallographic effects on potassium-argon ages----------.-----------------------------------------
  • Late Neogene and Quaternary Landscape Evolution of the Northern California Coast Ranges: Evidence for Mendocino Triple Junction Tectonics

    Late Neogene and Quaternary Landscape Evolution of the Northern California Coast Ranges: Evidence for Mendocino Triple Junction Tectonics

    Late Neogene and Quaternary landscape evolution of the northern California Coast Ranges: Evidence for Mendocino triple junction tectonics Jane Lock† Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA Harvey Kelsey‡ Department of Geology, Humboldt State University, Arcata, California 95521, USA Kevin Furlong§ Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA Adam Woolace# Department of Geology, Humboldt State University, Arcata, California 95521, USA ABSTRACT the double-humped pattern of uplift and our understanding of the lithospheric forces subsidence migrates, and the Coast Ranges that have built the orogen, and recognizing the A landscape records the surface response emerge. Smaller drainages develop and tectonic signal recorded by the landscape. We to tectonics at time scales intermedi- evolve by stream capture and fl ow reversal, describe how the surface responds to tectonics ate between short time-scale information and the two main divides migrate in concert in northern California, and we use the tectonic derived from seismic imaging and global with the triple junction. In contrast to the signal contained in the landscape to test and positioning systems and the long-term geo- systematic development of the small streams, develop our understanding of the geodynamics. logic record. We link late Neogene and the largest trunk streams can maintain grade A variety of mechanisms has been proposed Quaternary deposits and landforms in the through regions of high uplift, and coastal to explain the timing of uplift of the northern northern California Coast Ranges to the tec- river mouths remain stationary despite the California Coast Ranges. Dumitru (1989), using tonics of the Mendocino triple junction.