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Introduction San Andreas Fault: an Overview
Introduction This volume is a general geology field guide to the San Andreas Fault in the San Francisco Bay Area. The first section provides a brief overview of the San Andreas Fault in context to regional California geology, the Bay Area, and earthquake history with emphasis of the section of the fault that ruptured in the Great San Francisco Earthquake of 1906. This first section also contains information useful for discussion and making field observations associated with fault- related landforms, landslides and mass-wasting features, and the plant ecology in the study region. The second section contains field trips and recommended hikes on public lands in the Santa Cruz Mountains, along the San Mateo Coast, and at Point Reyes National Seashore. These trips provide access to the San Andreas Fault and associated faults, and to significant rock exposures and landforms in the vicinity. Note that more stops are provided in each of the sections than might be possible to visit in a day. The extra material is intended to provide optional choices to visit in a region with a wealth of natural resources, and to support discussions and provide information about additional field exploration in the Santa Cruz Mountains region. An early version of the guidebook was used in conjunction with the Pacific SEPM 2004 Fall Field Trip. Selected references provide a more technical and exhaustive overview of the fault system and geology in this field area; for instance, see USGS Professional Paper 1550-E (Wells, 2004). San Andreas Fault: An Overview The catastrophe caused by the 1906 earthquake in the San Francisco region started the study of earthquakes and California geology in earnest. -
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A new marine vertebrate assemblage from the Late Neogene Purisima Formation in Central California, part II: Pinnipeds and Cetaceans Robert W. BOESSENECKER Department of Geology, University of Otago, 360 Leith Walk, P.O. Box 56, Dunedin, 9054 (New Zealand) and Department of Earth Sciences, Montana State University 200 Traphagen Hall, Bozeman, MT, 59715 (USA) and University of California Museum of Paleontology 1101 Valley Life Sciences Building, Berkeley, CA, 94720 (USA) [email protected] Boessenecker R. W. 2013. — A new marine vertebrate assemblage from the Late Neogene Purisima Formation in Central California, part II: Pinnipeds and Cetaceans. Geodiversitas 35 (4): 815-940. http://dx.doi.org/g2013n4a5 ABSTRACT e newly discovered Upper Miocene to Upper Pliocene San Gregorio assem- blage of the Purisima Formation in Central California has yielded a diverse collection of 34 marine vertebrate taxa, including eight sharks, two bony fish, three marine birds (described in a previous study), and 21 marine mammals. Pinnipeds include the walrus Dusignathus sp., cf. D. seftoni, the fur seal Cal- lorhinus sp., cf. C. gilmorei, and indeterminate otariid bones. Baleen whales include dwarf mysticetes (Herpetocetus bramblei Whitmore & Barnes, 2008, Herpetocetus sp.), two right whales (cf. Eubalaena sp. 1, cf. Eubalaena sp. 2), at least three balaenopterids (“Balaenoptera” cortesi “var.” portisi Sacco, 1890, cf. Balaenoptera, Balaenopteridae gen. et sp. indet.) and a new species of rorqual (Balaenoptera bertae n. sp.) that exhibits a number of derived features that place it within the genus Balaenoptera. is new species of Balaenoptera is relatively small (estimated 61 cm bizygomatic width) and exhibits a comparatively nar- row vertex, an obliquely (but precipitously) sloping frontal adjacent to vertex, anteriorly directed and short zygomatic processes, and squamosal creases. -
Reef-Coral Fauna of Carrizo Creek, Imperial County, California, and Its Significance
THE REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CALIFORNIA, AND ITS SIGNIFICANCE . .By THOMAS WAYLAND VAUGHAN . INTRODUCTION. occur has been determined by Drs . Arnold and Dall to be lower Miocene . The following conclusions seem warranted : Knowledge of the existence of the unusually (1) There was water connection between the Atlantic and interesting coral fauna here discussed dates Pacific across Central America not much previous to the from the exploration of Coyote Mountain (also upper Oligocene or lower Miocene-that is, during the known as Carrizo Mountain) by H . W. Fair- upper Eocene or lower Oligocene . This conclusion is the same as that reached by Messrs. Hill and Dall, theirs, how- banks in the early nineties.' Dr. Fairbanks ever, being based upon a study of the fossil mollusks . (2) sent the specimens of corals he collected to During lower Miocene time the West Indian type of coral Prof. John C. Merriam, at the University of fauna extended westward into the Pacific, and it was sub- California, who in turn sent them to me . sequent to that time that the Pacific and Atlantic faunas There were in the collection representatives of have become so markedly differentiated . two species and one variety, which I described As it will be made evident on subsequent under the names Favia merriami, 2 Stephano- pages that this fauna is much younger than ctenia fairbanksi,3 and Stephanoccenia fair- lower Miocene, the inference as to the date of banksi var. columnaris .4 As the geologic hori- the interoceanic connection given in the fore- zon was not even approximately known at that going quotation must be modified . -
Appendices D Through I
Appendix D Operation & Maintenance Appendix D. Operation and Maintenance Plan Operation and Maintenance Plan This document presents the operation and maintenance (O&M) plan for Western Area Power Administration’s (Western) Sierra Nevada Region (SNR) transmission line systems. 1.0 Inspection/System Management In compliance with Western’s Reliability Centered Maintenance Program, Western would conduct aerial, ground, and climbing inspections of its existing transmission infrastructure since initial construction. The following paragraphs describe Western’s inspection requirements. Aerial Inspections Aerial inspections would be conducted a minimum of every 6 months by helicopter or small plane over the entire transmission system to check for hazard trees1 or encroaching vegetation, as well as to locate damaged or malfunctioning transmission equipment. Typically, aerial patrols would be flown between 50 and 300 feet above Western’s transmission infrastructure depending on the land use, topography, and infrastructure requirements. In general, the aerial inspections would pass over each segment of the transmission line within a one-minute period. Ground Inspections Annual ground inspections would check access to the towers/poles, tree clearances, fences, gates, locks, and tower hardware, and ensure that each structure would be readily accessible in the event of an emergency. They would allow for the inspection of hardware that would not be possible by air, and identify redundant or overgrown access roads that should be permanently closed and returned to their natural state. Ground inspections would typically be conducted by driving a pickup truck along the ROW and access roads. Detailed ground inspections would be performed on 20 percent of all lines and structures annually, for 100 percent inspection every 5 years. -
Deep Sea Drilling Project Initial Reports Volume 13
M. HAJOS 34.5. THE MEDITERRANEAN DIATOMS Marta Hajos, Hungarian Geological Institute, Budapest, Hungary INTRODUCTION species. The relevant information has been obtained from the references cited at the end of this chapter and from Ten washed samples taken at eight levels from the drill investigations of Hungarian fossiliferous localities. cores of the Mediterranean expedition of the Deep Sea The 175 taxa investigated belong primarily to the phyla Drilling Project were sent for study to the present writer by Chrysophyta and Bacillariophyta, and are accompanied in Paulian Dumitrica of the Geological Institute, Bucharest, subordinate numbers by representatives of Phytolitharia, Rumania. He had found these samples to be the richest Acritarcha, Radiolaria and Porifera. diatom-bearing sediments both in terms of species and The paleoecological assignments shown in Table 1 and individuals. the complete floral spectrum allow three paleo-ecological Two samples from Core 13 of Site 124—Balearic Rise1 divisions, representing three areas of the Mediterranean and were selected near levels of finely laminated dolomitic three different sedimentary facies, to be distinguished. marls with dark green to black interbeds. This dolomitic unit is part of the evaporite series cored in the deep Balearic Division 1 — Siliceous Dolomitic Marls of Site 124 Basin. All six samples from Sites 127 and 128 in the 2 Hellenic Trench of the Ionian Basin are from layers of The sediments of the two samples from Site 124 dark sapropelitic ooze, where the siliceous microfauna is (124-13-2, 89-90 cm and 124-13-2, 127-129 cm) were particularly abundant. The remaining two samples are from apparently deposited under the same ecological conditions. -
5 Geologic and Geotechnical Assessments
5 Geologic and Geotechnical Assessments 5.1 Regional and Site Geology Gilpin Geosciences, Inc. assessed the site conditions and prepared an engineering geologic evaluation of the project area, which is included as Appendix D. The site is located in the Coast Ranges geomorphic province that is characterized by northwest-southeast trending valleys and ridges. These are controlled by folds and faults that resulted from the collision of the Farallon and North American plates and subsequent shearing along the San Andreas Fault. The Merced Formation crops out in a broad trough that is partially exposed along the coastal bluffs of the site vicinity. It is of Plio-Pleistocene age (5 million to 10,000 years ago) and is characterized by sands and fine-grained deposits deposited in near-shore ocean environments with some units deposited onshore as dune fields. It is mapped as filling a northwest-southeast trending, fault-bounded basin that is exposed for approximately 3.8 miles along the sea cliffs from Mussel Rock on the south to the north end of Lake Merced. The Merced Formation is overlain by the Late Pleistocene age (125,000 to 10,000 years ago) Colma Formation, which is composed of sandy near-shore and beach deposits and recent dune sands. Several investigators have mapped the Merced Formation in the bluffs in the site vicinity. Hall (1966 and 1967) and Clifton and Hunter (1987) mapped the Merced Formation in detail to understand the age range and rapid changes in depositional environments preserved in the deposits outcropping along the Fort Funston / Thornton Beach coastal bluffs. -
Sediment Provenance and Dispersal of Neogene–Quaternary Strata of the Southeastern San Joaquin Basin and Its Transition Into the GEOSPHERE; V
Research Paper THEMED ISSUE: Origin and Evolution of the Sierra Nevada and Walker Lane GEOSPHERE Sediment provenance and dispersal of Neogene–Quaternary strata of the southeastern San Joaquin Basin and its transition into the GEOSPHERE; v. 12, no. 6 southern Sierra Nevada, California doi:10.1130/GES01359.1 Jason Saleeby1, Zorka Saleeby1, Jason Robbins2, and Jan Gillespie3 13 figures; 2 tables; 2 supplemental files 1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA 2Chevron North America Exploration and Production, McKittrick, California 93251, USA 3Department of Geological Sciences, California State University, Bakersfield, California 93311, USA CORRESPONDENCE: jason@ gps .caltech .edu CITATION: Saleeby, J., Saleeby, Z., Robbins, J., and ABSTRACT INTRODUCTION Gillespie, J., 2016, Sediment provenance and dis- persal of Neogene–Quaternary strata of the south- eastern San Joaquin Basin and its transition into We have studied detrital-zircon U-Pb age spectra and conglomerate clast The Sierra Nevada and Great Valley of California are structurally coupled the southern Sierra Nevada, California: Geosphere, populations from Neogene–Quaternary siliciclastic and volcaniclastic strata and move semi-independently within the San Andreas–Walker Lane dextral v. 12, no. 6, p. 1744–1773, doi:10.1130/GES01359.1. of the southeastern San Joaquin Basin, as well as a fault-controlled Neo- transform system as a microplate (Argus and Gordon, 1991; Unruh et al., 2003). gene basin that formed across the southernmost Sierra Nevada; we call this Regional relief generation and erosion of the Sierra Nevada are linked to sub- Received 9 May 2016 Accepted 31 August 2016 basin the Walker graben. -
USGS Professional Paper 1740
Age, Stratigraphy, and Correlations of the Late Neogene Purisima Formation, Central California Coast Ranges By Charles L. Powell II1, John A. Barron1, Andrei M. Sarna-Wojcicki1, Joseph C. Clark2, Frank A. Perry3, Earl E. Brabb4, and Robert J. Fleck1 Abstract Counties inland to the San Andreas Fault (fig. 1). These scat- tered outcrops have been grouped as the Purisima Formation The Purisima Formation is an important upper Miocene because they are all fine- to coarse-grained clastic rocks, with and Pliocene stratigraphic unit in central California, cropping dark andesitic fragments and locally abundant silicic tephra, out from the coast at Point Reyes north of San Francisco to and occupy the same stratigraphic position at their various more extensive exposures in the Santa Cruz Mountains to the exposures. Since first described by Haehl and Arnold (1904), south. The fine-grained rocks in the lower parts of the Puri- the Purisima Formation has been considered to be of Pliocene sima Formation record a latest Miocene transgressive event, or of late Miocene to Pliocene age. Differing age assignments whereas the middle and upper parts of the formation consist have resulted from the wide stratigraphic range of many com- of increasingly clastic-rich siltstones and sandstones resulting monly encountered megafossils and from the lack of agree- from uplift of adjacent coastal regions and the Sierra Nevada ment on the placement of the Miocene-Pliocene Series bound- during Pliocene transgressive and regressive sea-level events. ary between the provincial megafaunal chronology and that Exposures of the Purisima occur in three different, fault- of international usage. -
California State University, Northridge the Geology Of
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE THE GEOLOGY OF THE INNER BASIN MARGIN, NEWPORT BEACH TO DANA POINT, ORANGE COUNTY, CALIFORNIA A thesis submitted in partial satisfaction of the requirements for the degree of Master of Science in Geology by Stephen Charles Sterling January, 1982 The Thesis of Stephen Charles Sterling is approved: California State University, Northridge i i CONTENTS Page ABSTRACT INTRODUCTION 1 General Statement 1 Geographic Setting Bathymetric Setting 2 Previous Investigations 2 METHODS AND PROCEDURES 7 General Statement 7 Navigation 10 Velocity Analysis 10 Velocity Functions 11 Depth Migration 13 Ac know l edgemen ts 13 GEOLOGIC SETTING 15 REGIONAL STRATIGRAPHY 23 General Statement 23 Basement 23 Superjacent Rocks 26 Jurassic-Early Miocene 26 Middle to Late Miocene 27 Pliocene 32 Pleistocene 36 Holocene 37 SEISMIC STRATIGRAPHY 38 General Statement 38 iii Page Basement 38 r1i ocene 39 Pliocene 43 ONSHORE STRUCTURE 48 OFFSHORE STRUCTURE 52 General Statement 52 Faults 52 The Newport-Inglewood Fault Zone 52 Other Faults 58 Structural Highs and Lows 61 Correlation of Onshore-Offshore Geologic Features 63 NEOGENE EVOLUTION OF THE INNER BASIN MARGIN 67 General Statement 67 Pre-depositional Events 67 Neogene Events 69 Depositional History 69 Structural Evolution 73 SUMMARY AND CONCLUSIONS 75 REFERENCES 80 iv LIST OF ILLUSTRATIONS Figure Page .,.. l. Location of study area 4 2. Bathymetry of the inner basin margin 5 3. Tracklines of common depth point seismic lines in the study area 9 4. Major structural blocks of the Los Angeles basin 17 5. Location of geologic features referred to in text 19 6. Composite sections showing regional correlation of units 24 7. -
Palaeontological Society of Japan
Transactions and Proceedings of the Palaeontological Society of Japan New Series No. 87 Palaeontological Society of Japan September 30, 1972 Editor: Takashi HAMADA Associate editor: Yasuhide IWASAKI Officers for 1971 -1972 President: · Tokio SHIKAMA Councillors (* Executives): Kiyoshi ASANO*, Kiyotaka CHINZEI*, Takashi HAMADA*, Tetsuro HANAI*, Kotora HATAI, Itaru HAYAMI, Koichiro IcHIKAWA, Taro KANAYA, Kametoshi KANMERA, Tamio KOTAKA, Tatsuro MATSUMOTO*, Hiroshi OZAKI*, Tokio SHIKAMA *, Fuyuji TAKA!*, Yokichi TAKA YANAGI Secretaries: W ataru HASHIMOTO, Saburo KANNO Executive Committee General Affairs: Tetsuro HANAI, Naoaki AOKI Membership: Kiyotaka CHINZEI, Toshio KOIKE Finance: Fuyuji T AKAI, Hisayoshi !Go Planning : Hiroshi OZAKI, Kazuo ASAMA Publications Transactions : Takashi HAMADA, Y asuhide IwASAKI Special Papers: Tatsuro MATSUMOTO, Tomowo OzAWA " Fossils": Kiyoshi ASANO, Toshiaki TAKAYAMA All communications relating to this journal should be addressed to the PALAEONTOLOGICAL SOCIETY OF JAPAN c/o Business Center for Academic Societies, Japan Yayoi 2-4-16, Bunkyo-ku, Tokyo 113, Japan. Sole agent: University of Tokyo Press, Hongo, Tokyo Trans. Proc. Palaeont. Soc. Japan; N.S., No. 87, pp. 377-394, pl. 47, September 30, 1972 601. TWO SMALL DESMOCERATID AMMONITES FROM HOKKAIDO (STUDIES OF THE CRETACEOUS AMMONITES FROM HOKKAIDO AND SAGHALIEN-XXIV)* TATSURO MATSUMOTO!), TATSUO MURAMOT02> and AKITOSHI INOMN> ~l::.ffljitffti:-T:A.:c-e 7 :Af31.'H~~7 :..-'.:C-;1-1 ~ 2 f!fi: -t'O) 1 fi~~}]IJ!I!!)JJ3.!1E.;'f-O)r$-e / ~ =- 7 :..-'0) Mantelliceras japonicum 1\'.'17• t?:>iit L. t: "b 0)'"(', Wfr~Wfrm! C. VC:::.. :::.lr.ilcl!lXT .Qo :::.. hvinl<:f*~O)fE:Q~ 2 em JE.l?:>fO)'J''!!'t', JLI:l~v'ijWiWTrilfi~ "b t:,, mi»EEIB~Jl!:Q~y L. -
Gastropoda:Muricidae
The malacologicalsocietymalacological society of Japan Jeur. Malac,) fi re VENUS {Jap. - Vol, 5z No. 3 ( l99g): 2e9 223 Originand Biogeographic History of Ceratostoma (Gastropoda: Muricidae) Kazutaka AMANo and Geerat J. VERMEIJ of943ofGeoscience. Jbetsu Uhiversity oj' EZIucation. i2xmayashiki-1. Jbetsu, MigataDqpartmentPrellercture, -85i2 Japan, and Department of Geolegy and Center for Population Uitiversity Calijbrnia at Davis, One Shields Avenue, Davis, CA 95616 USABiology Abstract: We examined the two Neogene species of the ocenebrine muricid gastropod genus Ceratostoma Herrmannsen, 1846, from Japan and North Korea, namely, C. makiyamai The (Hatai & Kotaka, 1952) and C. sp,, both from the early middle Miecene. genus Ceratostotna is divisible into fouT groups based on C. nuttalli (Conrad), C. virginiae (Maury), C, fotiatum (Gemelin), and C. rorijIuum (Adams & Reeve). Three Miocene species from Kamehatka assigned by Russian workers to Ceratostoma are difficult to evaluate owing to poor preservation. Purpura turris Nomland, from the Pliecene of California, which was assigned to Ceratostoma by earlicr authors, is here tentatively assigned to Crassilabrum Jousseaume, 1880, have arisen the the early Miocene, it The genus Ceratostoma may in Atlantic. By had reached California, and then spTead westward to northeast Asia by earLy middle Mio- Miocene ccne time. This pattern of east to west expansion during the early half of the also characterizes many other north-temperate marine genera, including the ocenebrine NiiceUa. Keywords: origin, biogeography, Ceratostoma, Muricidae Introduction muricid Ceratostoma liye in shallow Recent species of the ocenebrine gastropod genus waters on both sides of the temperate and boreal North Pacific. There are six living species: C nuttaUi (Conrad) from California and Baja California, C. -
Qt53v080hx.Pdf
UC Berkeley PaleoBios Title A new Early Pliocene record of the toothless walrus Valenictus (Carnivora, Odobenidae) from the Purisima Formation of Northern California Permalink https://escholarship.org/uc/item/53v080hx Journal PaleoBios, 34(0) ISSN 0031-0298 Author Boessenecker, Robert W. Publication Date 2017-06-15 DOI 10.5070/P9341035289 Peer reviewed eScholarship.org Powered by the California Digital Library University of California PaleoBios 34:1-6, June 15, 2017 PaleoBios OFFICIAL PUBLICATION OF THE UNIVERSITY OF CALIFORNIA MUSEUM OF PALEONTOLOGY Boessenecker, Robert W. (2017). A New Early Pliocene Record of the Toothless Walrus Valenictus (Carnivora, Odobenidae) from the Purisima Formation of Northern California. Cover photo: Life restoration of the extinct Pliocene walrus Valenictus and flightless auks (Mancalla) hauled out on the rocky shore of the uplifted Coast Ranges of California (top right); cliff exposures of the Purisima Formation near Santa Cruz, from where Valenictus was collected by Wayne Thompson (left); bivalves, chiefly Clinocardium meekianum, exposed in the Purisima Formation near the locality (bottom). Photo credit and original artwork: Robert W. Boessenecker. Citation: Boessenecker, Robert W. 2017. A New Early Pliocene Record of the Toothless Walrus Valenictus (Carnivora, Odobenidae) from the Puri- sima Formation of Northern California. PaleoBios, 34. ucmp_paleobios_35289 A New Early Pliocene Record of the Toothless Walrus Valenictus (Carnivora, Odobenidae) from the Purisima Formation of Northern California ROBERT W. BOESSENECKER1,2 1Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 29424; [email protected] 2University of California Museum of Paleontology, University of California, Berkeley, CA 94720 The walrus (Odobenus rosmarus) is a large tusked molluskivore that inhabits the Arctic and is the sole living member of the family Odobenidae.