1 U.S. Geological Survey Earthquake Hazards Reduction Program Final

Total Page:16

File Type:pdf, Size:1020Kb

1 U.S. Geological Survey Earthquake Hazards Reduction Program Final U.S. Geological Survey Earthquake Hazards Reduction Program Final Technical Report Estimating Uncertainties of Seismic Hazard Parameters for Nevada Faults, Formations of a Nevada Quaternary Fault Working Group, and Gaining Consensus Fault Parameters Grant Award No. 06HQAG0126 Craig M. dePolo Nevada Bureau of Mines and Geology University of Nevada, Reno, NV 89557 (775) 784-6691 (775) 784-1709 FAX [email protected] Program Element: 1 Key Words: Paleoseismology, Quaternary Fault Behavior, Trench Investigations Abstract Twenty-two nationally recognized scientists, known as the Nevada Quaternary Fault Working Group, assembled and reviewed the current status of research on several of Nevada’s high risk faults, recommended seismic hazard values for faults when possible, and recommended future directions of research on major faults in Nevada. The Working Group met for two days in Reno and reviewed twelve of Nevada’s high-risk faults. Background reports for each fault were distributed to the scientists before the meeting. At the meeting each fault was reviewed, including relevant reports and studies, any known paleoearthquake history, estimated fault slip rates, estimated earthquake recurrence intervals, earthquake segmentation models, and estimated single-event displacements. The working group found that Nevada was still in the early stages of characterizing most of its high-risk faults, and more research and age determinations are needed to constrain seismic hazard parameters. Consequently, it was difficult for the group to determine many consensus fault parameters. The working group did, however, make a series of recommendations to help gain more information so that consensus values can be attained in the future. A follow-up meeting was strongly recommended by the group to review other high risk faults in Nevada, prioritize faults to be studied, and continue making recommendations for important studies. The initial recommendations presented here were developed at the meeting and reviewed by several working group members following the meeting. 1 Table of Contents Section Page Number Abstract 1 Introduction 3 Meeting Agenda 5 Recommended Research Priorities 7 Values used in the 2002 National Maps 13 Radiocarbon Dates 14 Genoa fault 20 Indian Hill fault 41 Carson City fault 49 Kings Canyon fault 58 Mt. Rose fault zone 66 Peavine Peak fault 83 Olinghouse fault zone 91 Pyramid Lake fault zone 104 Warm Springs Valley fault system 127 Las Vegas Valley fault system 143 Eglington fault 161 Black Hills fault zone 173 2 Introduction The Nevada Quaternary Fault Working Group was established to 1) critically evaluate the accuracy and completeness of the paleoseismic-trenching data, particularly with regard to earthquake timing, displacements, and fault slip rate, 2) assign consensus, preferred recurrence interval and vertical slip rate estimates with appropriate confidence limits to the faults reviewed, where the data is adequate to do so, and 3) identify critical gaps in the paleoseismic data and recommend where and what kinds of additional studies that should be performed to ensure Nevada’s earthquake hazard is adequately documented and understood. The Working Group members are: Nevada John Anderson, Nevada Seismological Laboratory John Bell Nevada Bureau of Mines and Geology Craig dePolo Nevada Bureau of Mines and Geology Jon Price Nevada Bureau of Mines and Geology Alan Ramelli, Nevada Bureau of Mines and Geology Tom Sawyer Piedmont GeoSciences Burt Slemmons UNR Emeritus Wanda Taylor UNLV Geoscience Department Steve Wesnousky UNR Center for Neotectonic Studies US Geological Survey Tony Crone Kathy Haller Suzanne Hecker Steve Personius Dave Schwartz Jim Yount External Larry Anderson U.S. Bureau of Reclamation Bill Bryant California Geological Survey John Caskey San Francisco State University Bill Lund Utah Geological Survey Susan Olig URS Tom Rockwell San Diego State University Ivan Wong URS 3 The Working Group convened in mid-November 2007 to review and assess the accuracy and completeness of the paleoseismic data available for eleven high- risk faults, and to make recommendations for additional research necessary to adequately understand and characterize these faults. The faults reviewed were: Reno-Carson City Urban Corridor Genoa fault Carson City fault Kings Canyon fault zone Indian Hill fault zone Mt. Rose fault zone Peavine Peak fault Olinghouse fault zone Pyramid Lake fault zone Warm Springs Valley fault system Las Vegas Urban Area Las Vegas Valley fault system Eglington fault (part of the Las Vegas Valley fault system) Black Hills fault zone This report includes the agenda of the working group meeting, the edited initial recommendations, and the background reports for the twelve faults that were supplied to the Working Group. 4 Nevada Quaternary Faults Working Group Meeting AGENDA November 19, 2007 8:00 Introduction, Agenda, and Purpose (dePolo) 8:10 Introduction and Purpose (USGS) 8:30 Utah Working Group Experience (Lund) 8:40 Estimating Two-Sigma Ranges and Uncertainties (Wong) 8:50 Goals, Approach, and Questions (dePolo) 9:00 Carson Range fault system Overview 9:05 Genoa fault 10:15 - BREAK - 10:45 Genoa fault (cont.) 11:00 Carson City faults (Carson City fault, Kings Canyon fault zone, and Indian Hill fault zone) 12:00 - LUNCH - 1:00 Mt. Rose fault zone 2:10 Carson Range fault system Earthquake Segmentation 2:30 - BREAK - 3:00 Peavine Peak fault 4:00 Las Vegas Valley fault system 5:00 Wrap-Up and Outstanding Issues 5:30 - ADJOURN - 5 November 20, 2007 8:00 Eglington fault 9:00 Black Hills fault 10:00 - BREAK - 10:30 Pyramid Lake fault zone 12:00 - LUNCH - 1:00 Warm Springs Valley fault system 2:00 Olinghouse fault zone 2:30 - BREAK - 3:00 Olinghouse fault zone (cont.) 3:30 Planning Special Consideration Zones 3:45 Prioritizing Identified Earthquake Research 4:15 Prioritizing the Next Faults for the Working Group to Review 4:30 Wrap-Up and Outstanding Issues 5:00 - ADJOURN - 6 Nevada Quaternary Fault Working Group Initial Recommendations for Research Priorities for studies of Quaternary Fault in Nevada The level of knowledge needed to reasonably characterize the large hazard and risk associated with Nevada’s major active faults is inadequate and requires an aggressive effort to acquire the geoscience data necessary to evaluate the seismic hazard to Nevada’s urban centers. These data can then be used by scientists, planners, and government officials to aid in adopting practices appropriate to enhance the safety of Nevada’s citizens. These are termed “initial recommendations” because a follow-up meeting is needed to further debate, refine, eliminate, and add to these comments. Divergent views exist among the Working Group members on the relative importance of some of these ideas. Further discussion is needed before these recommendations can be prioritized, and there are other high-risk faults in Nevada that need to be reviewed by the Working Group to explore whether there are additional recommendations. Planning Special Consideration Zones The State of Nevada should develop a strategy to create Planning Special Consideration Zones that will allow for safe development with respect to potentially hazardous earthquake faults. With input from design, engineering, and geoscience professionals, the creation of these zones will guide land-use planners, building officials, and developers in minimizing the adverse effects of fault surface rupture and other earthquake-related hazards. The late Quaternary faults in Nevada urban areas should then be mapped and zoned at a scale of 1:24,000 using the developed strategy. Northern Nevada General Needs for Northern Nevada Abundant information related to late Quaternary faulting and surface ruptures likely exists in a variety of unpublished reports and documents prepared by consultants and construction firms in the Reno-Carson City urban corridor. The contents of these reports could provide new insight into the activity rates or ages of surface ruptures on various fault zones or strands. The working group recommends that an effort be made to systematically poll geoscience consultants in the area, and to collect and archive non-proprietary reports that contain information relevant to fault activity and related hazards. This archive should be based at a state agency where the information will be publicly available. 7 Mt. Rose fault zone The Mt. Rose fault zone includes the Washoe Valley fault zone, the Little Valley fault, and the Virginia Lake fault zone. Currently available paleoseismic data are inadequate to characterize the times of prehistoric large earthquakes along the fault zone. The close proximity of this fault system to the Reno-Carson City urban centers makes its study a priority. The only compelling constrains on paleoearthquakes on the Mt. Rose fault zone from existing data are that two surface-rupturing earthquakes have occurred since about 1,553-1,862 cal. yr BP. Geological and geophysical studies are needed to develop paleoseismic records of earthquakes for the major strands of the zone. These records can be developed by first systematically mapping of fault strands and determining the ages of various faulted deposits. These studies can yield valuable information about long-term slip rates and the time of the most recent event. Geophysical and subsurface studies may be helpful in defining the down-dip and along-strike links between various strands. Eventually, trenching studies at selected sites will be required to define critical parameters such as displacement per event, the times
Recommended publications
  • Rood Et Al 2011 EPSL SNFFZ.Pdf
    This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Earth and Planetary Science Letters 301 (2011) 457–468 Contents lists available at ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl Spatiotemporal patterns of fault slip rates across the Central Sierra Nevada frontal fault zone Dylan H. Rood a,b,⁎, Douglas W. Burbank a, Robert C. Finkel c,d a Department of Earth Science, University of California, Santa Barbara, CA 93106, USA b Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA c CEREGE, Aix en Provence, France d Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA article info abstract Article history: Patterns in fault slip rates through time and space are examined across the transition from the Sierra Nevada Received 23 June 2010 to the Eastern California Shear Zone–Walker Lane belt. At each of four sites along the eastern Sierra Nevada Received in revised form 30 October 2010 frontal fault zone between 38 and 39° N latitude, geomorphic markers, such as glacial moraines and outwash Accepted 2 November 2010 terraces, are displaced by a suite of range-front normal faults.
    [Show full text]
  • Communityw O 7 S 0 B &
    INC PULATION REA PO DU SE RING U 20 NL % 13 2 V EN 7, 5 RO 8 . L 2 C LM 4 S 7 N EN 8 Y 062,2 3 T , 5 E 6 T E 3 NR , G 2 N O 6 A % EW N L I R COM S LM 2 G VE E C E 9 N A A RS N N I L RE T A .6 FR 3 V 3 I N 3 O , M E 3 L IO NR 9 U T OL F A LM 5 N E O S E ALIFO N L C R T R N M T A I U 4 U A S Q . 7 T E A O . o C 0 R C 0 0 9 E M 1 A P 9 FO 0 F G M IN R N O E T O T IN H 1 S S T E N O U E F C O 8 1 I C H G . R O S A 9 T R T N 7 I E 9 M V 0 E A 6 Y S R $ T S 3,086,745,000(ASSISTED BY LVGEA) S E NEW COMPANIES U N I D 26 S N I ANNUAL HOME SALES N 7 U 4 R EMPLOYMENT 5 T E E , COMMUNITYW O 7 S 0 B & 4 A T , 5 L 7 las vegasA perspective E 895,700 , 9.5% 6 L 7 6 UNEMPLOYMENT 4 0 RATE 6 E M M IS E LU A R LUM VO P TOU VO R M A CO ITOR E L R M VIS G TE S A T M N O M V E 6 H O G M ER M SS O $ .
    [Show full text]
  • Las Vegas Aces
    Welcome to LasVegasRelocation Guide to Southern Nevada Trusted everywhere every day. Contents LAS VEGAS VALLEY INFORMATION Climate & Population ......................................................4 Demographics ..................................................................5 Zip Code Map ..................................................................6 Newcomer Resources .......................................................7 Utility Information ...........................................................8 DMV/ Voting ....................................................................9 Employment ...................................................................10 Transportation ................................................................11 Housing ..........................................................................12 Museums/ Galleries .......................................................13 Libraries .........................................................................14 Hospitals ........................................................................15 Churches ........................................................................16 Youth Activities ..............................................................18 Senior Services ...............................................................19 Parks ...............................................................................20 Outdoor Recreation Activities ........................................21 Golfing ...........................................................................22
    [Show full text]
  • 150 Geologic Facts About California
    California Geological Survey - 150th Anniversary 150 Geologic Facts about California California’s geology is varied and complex. The high mountains and broad valleys we see today were created over long periods of time by geologic processes such as fault movement, volcanism, sea level change, erosion and sedimentation. Below are 150 facts about the geology of California and the California Geological Survey (CGS). General Geology and Landforms 1 California has more than 800 different geologic units that provide a variety of rock types, mineral resources, geologic structures and spectacular scenery. 2 Both the highest and lowest elevations in the 48 contiguous states are in California, only 80 miles apart. The tallest mountain peak is Mt. Whitney at 14,496 feet; the lowest elevation in California and North America is in Death Valley at 282 feet below sea level. 3 California’s state mineral is gold. The Gold Rush of 1849 caused an influx of settlers and led to California becoming the 31st state in 1850. 4 California’s state rock is serpentine. It is apple-green to black in color and is often mottled with light and dark colors, similar to a snake. It is a metamorphic rock typically derived from iron- and magnesium-rich igneous rocks from the Earth’s mantle (the layer below the Earth’s crust). It is sometimes associated with fault zones and often has a greasy or silky luster and a soapy feel. 5 California’s state fossil is the saber-toothed cat. In California, the most abundant fossils of the saber-toothed cat are found at the La Brea Tar Pits in Los Angeles.
    [Show full text]
  • 2019 Scec Annual Technical Report
    1 2019 SCEC ANNUAL TECHNICAL REPORT - SCEC Award 19031 Evaluate & Refine 3D Fault and Deformed Surface Geometry to Update & Improve the SCEC Community Fault Model Craig Nicholson Marine Science Institute, University of California, Santa Barbara, CA 93106-6150 Summary Since SCEC3, I and my colleagues Andreas Plesch, Chris Sorlien, John Shaw, Egill Hauksson, and now Scott Marshall continue to make steady and significant improvements to the SCEC Community Fault Model (CFM), culminating in the release of CFM-v5.3 [Nicholson et al., 2019]. This on-going systematic update represents a substantial improvement of 3D fault models for southern California. The CFM-v3 fault set was expanded from 170 faults to over 860 fault objects and alternative representations in CFM- v5.3 that define nearly 400 faults organized into 106 complex fault systems (Fig.1). Most of these updated 3D fault models were developed by UCSB, or to which UCSB made significant contributions. This includes all the major fault models of major fault systems (e.g., San Andreas, San Jacinto, Elsinore- Laguna Salada, Newport-Inglewood, Imperial, Garlock, etc.), and most major faults in the Mojave, Eastern & Western Transverse Ranges, offshore Borderland, and updated faults within designated Special Fault Study or Earthquake Gate Areas (Fig.1) [Nicholson et al., 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019; Sorlien et al, 2012, 2014, 2015, 2016; Sorlien and Nicholson, 2015]. These new models allow for more realistic, curviplanar, complex 3D fault geometry, including changes in dip and dip direction along strike and down dip, based on the changing patterns of earthquake hypocenter and nodal plane alignments and, where possible, imaging subsurface fault geometry with industry seismic reflection data.
    [Show full text]
  • Quaternary Fault and Fold Database of the United States
    Jump to Navigation Quaternary Fault and Fold Database of the United States As of January 12, 2017, the USGS maintains a limited number of metadata fields that characterize the Quaternary faults and folds of the United States. For the most up-to-date information, please refer to the interactive fault map. Kings Canyon fault zone (Class A) No. 1654 Last Review Date: 2014-06-10 citation for this record: Adams, K., Sawyer, T.L., and Haller, K.M., compilers, 2014, Fault number 1654, Kings Canyon fault zone, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, https://earthquakes.usgs.gov/hazards/qfaults, accessed 12/14/2020 02:35 PM. Synopsis This nearly continuous north- to northeast-striking fault zone consists of: (1) generally range- and hill-front faults bounding Carson Range north of U.S. 50 and along southeast front of Sugarloaf; (2) piedmont faults adjacent to the range- and hill-front faults form near mouth of Kings Canyon northeastward to Indian Mountain; and (3) primarily intermontane, bedrock faults extending from Kings Canyon northward to southern margin of Washoe Valley. Fault zone may be structurally related to the Carson Range fault [1285] to the south based on a possibly splaying relationship. The intermontane fault are included in this zone because of similar strike, recency of movement, and proximity to other faults in the zone. Detailed surficial and bedrock mapping are the sources of data. Trench investigations have been accomplished, but detailed studies of scarp morphology have not
    [Show full text]
  • Air Photo Lineaments, Southern Sierra Nevada, California
    DEPARTMENT OF THE INTERIOR U. S. GEOLOGICAL SURVEY Air photo lineaments, southern Sierra Nevada, California by Donald C. Ross1 Open-File Report 89-365 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U. S. Government. 'Menlo Park, California 1989 CONTENTS Page Introduction .................................................................................................................................... i Discussion .................................................................................................................................... 2 Air photo lineaments along known faults.............................................................................. 2 San Andreas and Garlock faults................................................................................. 2 Kern Canyon-Breckenridge-White Wolf fault zone.................................................. 2 Durmc>c>d fault?.........7...:............... 2 Pinyon Peak fault....................................................................................................... 4 Jawbone fault............................................................................................................. 4 Sierra Nevada fault.................................................................................................... 4 Kern River fault........................................................................................................
    [Show full text]
  • The Stratigraphie Evolution of the El Paso Basin, Southern California: Implications for the Miocene Development of the Garlock Fault and Uplift of the Sierra Nevada
    The stratigraphie evolution of the El Paso basin, southern California: Implications for the Miocene development of the Garlock fault and uplift of the Sierra Nevada DANA P. LOOMIS Department of Geology, University of North Carolina, Chapel Hill, North Carolina 27514 DOUGLAS W. BURBANK Department of Geological Sciences, University of Southern California, Los Angeles, California 90089-0740 ABSTRACT This paper presents the results of stratigraphic, chronologic, and tec- tonic investigations of the Miocene Ricardo Group in the El Paso basin. The Ricardo Group is a 1,700-m-thick sequence of Miocene vol- Sedimentary and magnetostratigraphic data provide evidence for the onset canic rocks and continental sedimentary rocks deposited between ~19 of east-west extension north of the Garlock fault about 10 Ma and for the and 7 Ma in the El Paso basin, near the junction of the Garlock fault emergence of the Sierra Nevada as a topographic upland about 8 Ma. In and the Sierra Nevada frontal fault in southern California. The combi- addition to these age constraints for the Garlock fault and Sierra Nevada, nation of stratigraphic and structural data from the Ricardo Group this analysis also provides an opportunity to test some plate-tectonic mod- with chronologic and rotational histories derived from magnetostrati- els for the late Cenozoic sedimentary and tectonic evolution of southern graphic and radiometric studies provides some new constraints for the California. Sedimentary evidence from the El Paso basin is largely consist- morphotectonic emergence of the Sierra Nevada, the initiation of ent with proposals that basin growth and sedimentation (Glazner and strike-slip movement on the Garlock fault, and related east-west ex- Loomis, 1984) and basin-and-range extension (Ingersoll, 1982; Glazner tension in the southern Basin and Range region.
    [Show full text]
  • Tectonic Controls on Alluvial Fan Dissection in the El Paso Mountains
    Gaffney 1 Tectonic Controls on Alluvial Fan Dissection in the El Paso Mountains A Senior Project Presented to the Faculty of the Natural Resources and Environmental Sciences Department California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Bachelor of Science By Michael Gaffney © Michael Gaffney June, 2018 Gaffney 2 ACKNOWLEDGEMENTS: I would like to thank Dr. Antonio Garcia for his tremendous support and guidance on this project. ABSTRACT: The localized dissection of alluvial fans along the western El Paso Mountains is under question. A relatively minor, south dipping normal fault, previously unmentioned in scientific literature, cuts across Quaternary terraces and alluvial fans in the piedmont of the El Paso Mountains. The linear trend of footwall uplift and the pattern of stream incision into the footwall adjacent to the linear trend of footwall uplift reveal that fan dissection is a result of base level fall caused by ongoing tectonism along the El Paso fault system. The regional importance is discussed as the timing of faulting reveals relatively recent uplift of the El Paso Mountains, and a model of extensional strain partitioning is argued for to account for this uplift in the tectonically complex Garlock Fault Zone. Gaffney 3 INTRODUCTION: The study location is in Red Rock Canyon State Park, which is close to the boundary between the Sierra Nevada mountain range and the Mojave Desert (Fig. 1). The precise study area is in the southern part of Red Rock Canyon State Park along the mountain front of the El Paso Mountains (Fig. 2). The focus is on the western extent of the El Paso Mountains because the alluvial fans are more dissected here than they are along the rest of the range (Fig.
    [Show full text]
  • Relocation Guide
    CORPORATE CIRCLE MAIN SUMMERLIN 2370 Corporate Circle, Suite 100 9075 W. Diablo Drive, Suite 100 7201 W. Lake Mead Boulevard, Suite 101 Henderson, NV 89074 Las Vegas, NV 89148 Las Vegas, NV 89128 702.940.0200 702.407.8894 702.836.80001 Welcome to Chicago Title of Nevada Chicago Title is a member of the Fidelity National Financial (NYSE:FNF) family of companies, a leading provider of title insurance, mortgage services, and diversified services. The nations largest title insurance company. We pride ourselves in our service and the ability to restructure our workflow to meet that of our clients. We understand that as our customer, you need Chicago Title to make the process of your transaction as seamless and as smooth as possible! With over 1,100 title companies, and 16,000 employees throughout the United States and Canada, our title insurance and settlement services business is truly nationwide, but also extremely connected to the local markets we serve. Whether you are a first time home buyer, sophisticated developer, or investor our talented and industry-specific management teams, as well as motivated, professional workforce with market-specific knowledge and expertise, create value for clients, customers, and shareholders by maintaining industry-leading margins and service levels. Our collaborative management process is aligned with market demands, ensuring our operations consider local market conditions when leveraging technology and work process in order to improve efficiencies. Our goal is to foster and support a corporate culture where our employees and managers seek to operate independently and profitably at the local level, while continually learning and improving performance based on best practices shard across the enterprise.
    [Show full text]
  • Stadiums, Arenas and Events Centers
    Stadiums, Arenas and Events Centers As legalized gaming has spread throughout the United States and the around the world, Las Vegas has diversified its non-gaming offerings to continue to attract visitors as a world-class tourist destination. Special events, such as concerts and sporting events, play an increasingly larger role in the diversity of the visitor experience, and those events are frequently hosted by a handful of high-capacity venues such as stadiums, arenas and events centers. After building 60,000 rooms during the past two decades, Las Vegas is now building reasons to fill them – stadiums, arenas and events centers are key element of that shift. Large-Capacity Multi-Purpose Venues in Southern Nevada Maximum Year Venue Capacity Built Sam Boyd Stadium 40,000* 1971 T-Mobile Arena 20,000 2016 Thomas & Mack Center 18,500 1983 MGM Grand Garden Arena 16,800 1993 Mandalay Bay Events Center 12,000 1999 Cashman Field 10,000 1983 Orleans Arena 9,000 2003 * Sam Boyd Stadium capacity ranges from 36,000 to 40,000 depending on seating arrangement Today, special events play a larger role in attracting visitors to Las Vegas than just a decade ago. In 2004, 4 percent of visitors cited a special event as the primary reason for their visit, a number that had been relatively unchanged for years before and after, according the annual visitor profile survey by the Las Vegas Convention and Visitors Authority (“LVCVA”). That figure has climbed higher in recent years, reaching 9 percent in 2013 before settling at 7 percent in 2014.
    [Show full text]
  • Late Quaternary Deformation and Seismic Risk Vl in the Northern Sierra Nevada-Great Basin Boundary Zone Near the Sweetwater Mountains, California and Nevada
    University of Nevada Reno !Late Quaternary deformation and seismic risk vl in the northern Sierra Nevada-Great Basin Boundary Zone near the Sweetwater Mountains, California and Nevada A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology by Garry Fallis Hayes W\ April 1985 i MINIS 1 LIBRARY University of Nevada Reno April 1985 ii ABSTRACT Remote-sensing, seismic and field studies indi­ cate three major zones of Quaternary deformation near the Sweetwater Mountains. Holocene fault scarps are present in the Antelope, Little Ante­ lope, Smith and Bridgeport Valleys, and in the Sonora Basin. Two other vaguely defined zones, between Carson and Antelope valleys, and from the Bridgeport Valley east to Bald Mountain, may repre­ sent Mio-Pliocene zones of faulting which more recently have acted as conjugate shears releasing stress between fault basins in the Western Great Basin between the Sierra Nevada and Walker Lane shear zone. The northern portion of the Sierra Nevada-Great Basin Boundary Zone is less active than the south­ ern part in Owens Valley, as shown by lower slip rates, shorter fault lengths and lower levels of historical seismicity. Maximum Credible Earthquake magnitudes for the fault basins range from 6.3 to 7.2, with expected displacements of 3 meters or more. iii ACKNOWLEDGEMENTS The author would like to thank Dr. D.B. Slemmons, Craig DePolo and J.O. Davis for helpful discussions during the course of this study. Special thanks to Craig DePolo, Susan Hciyss and Ron Smith, who assisted with the field studies, and to Glenn Hayes who assisted with the manuscript preparation.
    [Show full text]