DOCSLIB.ORG

UNIVERSITY of CALIFORNIA, SAN DIEGO Marine Geophysical Study

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

UNIVERSITY OF CALIFORNIA, SAN DIEGO Marine Geophysical Study of Cyclic Sedimentation and Shallow Sill Intrusion in the Floor of the Central Gulf of California A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Oceanography by Jared W. Kluesner Committee in Charge: Professor Peter Lonsdale, Chair Professor Paterno Castillo Professor Graham Kent Professor Falko Kuester Professor Michael Tryon Professor Edward Winterer 2011 Copyright Jared Kluesner, 2011 All rights reserved. The Dissertation of Jared W. Kluesner is approved, and it is acceptable in quality and in form for publication on microfilm and electronically: Chair University of California, San Diego 2011 iii To my parents, Tony and Donna Kluesner and my grandfather James Kluesner iv "...Let us go, we said, into the Sea of Cortez, realizing that we become forever a part of it" The Log from the Sea of Cortez John Steinbeck v TABLE OF CONTENTS Signature Page ...................................................................................... iii Dedication.............................................................................................. iv Epigraph ................................................................................................ v Table of Contents .................................................................................. vi List of Figures ........................................................................................ ix Acknowledgments ................................................................................. xii Vita......................................................................................................... xv Abstract ................................................................................................. xvi Chapter 1. Introduction .......................................................................... 1 1.1 High-Resolution Imaging of Rift-To-Drift Processes................... 2 1.2 References ................................................................................ 8 Chapter 2. Influence of Glacial-Interglacial Cyclicity on Sedimentation and Axial Rift Structure in the Southern Trough, Guaymas Basin.................................................................................... 13 2.1 Abstract ...................................................................................... 14 2.2 Introduction................................................................................. 15 2.3 Geophysical Data....................................................................... 19 2.4 Results and Interpretations ........................................................ 20 2.4.1 Seismic Stratigraphy ........................................................... 20 2.4.2 Lithology and Age of the Seismic Stratigraphic Units.......... 22 2.4.3 Record of Tectonic Deformation and Axial Trough Filling ... 31 vi 2.5 Influence of Glacial/Interglacial Cyclicity on Guaymas Basin Sedimentation ............................................................................ 38 2.6 Cyclic Seismic Stratigraphy Elsewhere Along the Gulf of California Plate Boundary........................................................... 44 2.7 Summary of Conclusions ........................................................... 49 2.8 Acknowledgments ...................................................................... 54 2.9 References ................................................................................. 55 Chapter 3. Geological and Hydrological Effects of Young Intrusive Magmatism in the Central and Southern Gulf of California.. 79 3.1 Abstract ...................................................................................... 80 3.2 Introduction................................................................................. 81 3.3 Geological Setting ...................................................................... 86 3.4 Geophysical Data....................................................................... 89 3.5 Results ....................................................................................... 92 3.5.1 Seismic Characteristics of Magmatic Sills........................... 92 3.5.2 Magmatic Sills and Deformation.......................................... 95 3.5.3 Sills Feeding Sills? .............................................................. 105 3.5.4 Buried Lava Flows?............................................................. 106 3.5.5 Sill Geometry and Emplacement Depth .............................. 107 3.5.6 Sill-Driven Hydrothermal Fluid-Flow.................................... 115 3.5.7 Hydrocarbon Generation, Trapping, and Leakage .............. 124 3.6 Comparison with Magma Intrusion Around Other Turbidite- vii Smothered Spreading Centers................................................... 128 3.7 Conclusions................................................................................ 130 3.8 Acknowledgments ...................................................................... 134 3.9 References ................................................................................. 135 Chapter 4. Conclusions ......................................................................... 209 viii LIST OF FIGURES Figure 1.1 Regional Map of Central Gulf of California ........................... 11 Figure 2.1 Topography of Guaymas and Carmen Basins ..................... 63 Figure 2.2 Multibeam Bathymetry of Study Area in Southwestern Guaymas Basin, and the Adjacent Baja California Continental slope.................................................................. 65 Figure 2.3 3D Cutaway of MCS Profile 1 and Multibeam Bathymetry, Crossing the Southern Trough of Guaymas Basin ............... 67 Figure 2.4 MCS Profile 2 ....................................................................... 69 Figure 2.5 Northwestern Sections of MCS Lines 1 and 2 Tied to DSDP Site 478 Drilling Results........................................................ 71 Figure 2.6 Simplified Rift Evolution Model for the Southern Trough in Guaymas Basin .................................................................... 73 Figure 2.7 Detailed Bathymetric Map of Carmen Basin and a Seismic Transit of Carmen axis.......................................................... 75 Figure 2.8 The Turbidite-Accumulating North Pescadero Transform Valley Near its Intersection with the Axial Rift Valley of the North Pescadero Spreading Axis ......................................... 77 Figure 3.1 Topography of Central and Southern Gulf of California........ 147 Figure 3.2 Map of Sedimentary Features in the Central and Southern Gulf of California................................................................... 149 Figure 3.3 Structural Interpretation Map of Central and Southern Gulf of California .......................................................................... 151 Figure 3.4 MCS Profile A ....................................................................... 153 Figure 3.5 MCS Profile B ....................................................................... 155 ix Figure 3.6 MCS Profile C....................................................................... 157 Figure 3.7 MCS Profile D....................................................................... 159 Figure 3.8 MCS Profile E ....................................................................... 161 Figure 3.9 MCS Profile F ....................................................................... 163 Figure 3.10 MCS Profile G..................................................................... 165 Figure 3.11 Bathymetric Map of 3.5 kHz Survey Near Farallon Transform Scarp................................................................. 167 Figure 3.12 3D Grid of the BEKL 3.5 kHz Survey.................................. 169 Figure 3.13 MCS Profiles H and I .......................................................... 171 Figure 3.14 MCS Profile M .................................................................... 173 Figure 3.15 MCS Profile N..................................................................... 175 Figure 3.16 MCS Profile O..................................................................... 177 Figure 3.17 MCS Profile K ..................................................................... 179 Figure 3.18 Plot of Upturned Sill Width vs. Emplacement Depth .......... 181 Figure 3.19 Bathymetric Map Located at the Bend in the Northern Trough of Guaymas Basin.................................................. 183 Figure 3.20 MCS Profile J...................................................................... 185 Figure 3.21 Boundary Element Based Model Panels A, B and C.......... 187 Figure 3.22 Boundary Element Based Model Panels D, E and F.......... 189 Figure 3.23 Sill Emplacement Model Panels A, B, C, D, E, and F ........ 191 Figure 3.24 MCS Profile P ..................................................................... 193 Figure 3.25 MCS Profile H and Analog 3.5 kHz Profile ......................... 195 Figure 3.26 Fluid-Flow Model Panels A, B, C, and D ............................ 197 Figure 3.27 3D Cutaway of MCS Profile M............................................ 199 Figure 3.28 MCS Profile L ..................................................................... 201 x Figure 3.29 Subsection of Profile F ....................................................... 203 Figure 3.30 3.5 kHz Profile Southwest of Carmen Axis......................... 205 Figure 3.31 Multichannel Seismic Reflection
Recommended publications
  • Extension Del Campo De Cerro Prieto Y Futuras Zonas Con Probabilidades Geotermicas En El Valle De Mexicali H

    Extension Del Campo De Cerro Prieto Y Futuras Zonas Con Probabilidades Geotermicas En El Valle De Mexicali H

    EXTENSION DEL CAMPO DE CERRO PRIETO Y FUTURAS ZONAS CON PROBABILIDADES GEOTERMICAS EN EL VALLE DE MEXICALI H. L. Fonseca L., A. de la Pena 1., 1. Puente c., y E. Diaz C. Comisi6n Federal de Electricidad Coordinadora Ejecutiva de Cerro Prieto Mexicali, Baja California, Mexico RESUMEN instalar una capacidad de generaci6n geotermoel~ctrica del orden de 1000 W~ en e1 Valle de 1:1exicali. En una evaluacion de las condi'eiones" geoliigico-estructurales" dentro de sumarco Con el afan de contribuir al desarrollo de las tectonico regional, y con la integracion de los obTas geotermicas de esta regi-on, en e1 presente trabaj os geologicos y geoU.sicos realizados en el traoajo se e:xponen algunas condiciones geologico­ Campo de Cerro Prieto, se intenta estaolecer la es"tTucturales proprcias para la e:xistencia de posible extension del mismo, asi como otras zonas amoientes geotermicos y la relacion de ciertas que podrian tener probaoilidades de desarrollo anomalJ1as geofisicas con zonas que podrlan tener geotermico dentro del Valle de Mexicali, probabilidades de desarrollo incluyendo la posible extensron del Campo de Cerro Prieto. Este trabajo tiene como antecedente la informacion ootenida de los pozos cons·tru:Cdos· a 1a Cabe mencionar que algunas areas interpretadas fecha, y la informacion geologica y geof5!sica como prospectos geotermicos, han sido senaladas disponible con 10 cual se esta contriDuyendo a la tomando en cuenta la posicion formacion del modelo geologico que en forma informacion respecto a los generalizada establece la geometrta de 10 que Valle Im~erial y, 1a podria constituir el yacimiento geot~rmico del de encontrarse en maximos campo de Cerro Prieto.
  • In the Southern Gulf of California: the Role of the Southern Baja California Microplate and Its Eastern Boundary Zone

    In the Southern Gulf of California: the Role of the Southern Baja California Microplate and Its Eastern Boundary Zone

    University of South Florida Scholar Commons School of Geosciences Faculty and Staff Publications School of Geosciences 2-2020 Quantifying Rates of “Rifting while Drifting” in the Southern Gulf of California: The role of the Southern Baja California Microplate and its Eastern Boundary Zone Paul J. Umhoefer Northern Arizona University C. Plattner Ludwig-Maximilians Universität Rocco Malservisi University of South Florida, [email protected] Follow this and additional works at: https://scholarcommons.usf.edu/geo_facpub Part of the Earth Sciences Commons Scholar Commons Citation Umhoefer, Paul J.; Plattner, C.; and Malservisi, Rocco, "Quantifying Rates of “Rifting while Drifting” in the Southern Gulf of California: The role of the Southern Baja California Microplate and its Eastern Boundary Zone" (2020). School of Geosciences Faculty and Staff Publications. 2226. https://scholarcommons.usf.edu/geo_facpub/2226 This Article is brought to you for free and open access by the School of Geosciences at Scholar Commons. It has been accepted for inclusion in School of Geosciences Faculty and Staff Publications by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. RESEARCH Quantifying rates of “rifting while drifting” in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone Paul J. Umhoefer1,*, C. Plattner2, and R. Malservisi3 1SCHOOL OF EARTH AND SUSTAINABILITY, NORTHERN ARIZONA UNIVERSITY, 624 S. KNOLES DRIVE, ASHURST BUILDING, ROOM A108, FLAGSTAFF, ARIZONA 86011, USA 2DEPARTMENT FÜR UMWELT- UND GEOWISSENSCHAFTEN, LUDWIG-MAXIMILIANS-UNIVERSITÄT MÜNCHEN, SEKTION GEOLOGIE, LUISENSTRASSE 37, 80333 MÜNCHEN, GERMANY 3SCHOOL OF GEOSCIENCES, UNIVERSITY OF SOUTH FLORIDA, 4202 E. FOWLER AVENUE, NES107, TAMPA, FLORIDA 33620, USA ABSTRACT The southern Baja California (Mexico) microplate has been rapidly moving away from the North America plate since ca.
  • Preliminary Catalog of the Sedimentary Basins of the United States

    Preliminary Catalog of the Sedimentary Basins of the United States

    Preliminary Catalog of the Sedimentary Basins of the United States By James L. Coleman, Jr., and Steven M. Cahan Open-File Report 2012–1111 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Coleman, J.L., Jr., and Cahan, S.M., 2012, Preliminary catalog of the sedimentary basins of the United States: U.S. Geological Survey Open-File Report 2012–1111, 27 p. (plus 4 figures and 1 table available as separate files) Available online at http://pubs.usgs.gov/of/2012/1111/. iii Contents Abstract ...........................................................................................................................................................1
  • The Paleoecology and Fire History from Crater Lake

    The Paleoecology and Fire History from Crater Lake

    THE PALEOECOLOGY AND FIRE HISTORY FROM CRATER LAKE, COLORADO: THE LAST 1000 YEARS By Charles T. Mogen A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Environmental Science and Policy Northern Arizona University August 2018 Approved: R. Scott Anderson, Ph.D., Chair Nicholas P. McKay, Ph.D. Darrell S. Kaufman, Ph.D. Abstract High-resolution pollen, plant macrofossil, charcoal and pyrogenic Polycyclic Aromatic Hydrocarbon (PAH) records were developed from a 154 cm long sediment core collected from Crater Lake (37.39°N, 106.70°W; 3328 m asl), San Juan Mountains, Colorado. Several studies have explored Holocene paleo-vegetation and fire histories from mixed conifer and subalpine bogs and lakes in the San Juan and southern Rocky Mountains utilizing both palynological and charcoal studies, but most have been at relatively low resolution. In addition to presenting the highest resolution palynological study over the last 1000 years from the southern Rocky Mountains, this thesis also presents the first high-resolution pyrogenic PAH and charcoal paired analysis aimed at understanding both long-term fire history and the unresolved relationship between how each of these proxies depict paleofire events. Pollen assemblages, pollen ratios, and paleofire activity, indicated by charcoal and pyrogenic PAH records, were used to infer past climatic conditions. Although the ecosystem surrounding Crater Lake has remained a largely spruce (Picea) dominated forest, the proxies developed in this thesis suggest there were two distinct climate intervals between ~1035 to ~1350 CE and ~1350 to ~1850 CE in the southern Rocky Mountains, associated with the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) respectively.
  • Why Did the Southern Gulf of California Rupture So Rapidly?—Oblique Divergence Across Hot, Weak Lithosphere Along a Tectonically Active Margin

    Why Did the Southern Gulf of California Rupture So Rapidly?—Oblique Divergence Across Hot, Weak Lithosphere Along a Tectonically Active Margin

    Why did the Southern Gulf of California rupture so rapidly?—Oblique divergence across hot, weak lithosphere along a tectonically active margin breakup, is mainly dependent on the thermal structure, crust- Paul J. Umhoefer, Geology Program, School of Earth Sciences & Environmental Sustainability, Northern Arizona University, al thickness, and crustal strength of the lithosphere when Flagstaff, Arizona 86011, USA; [email protected] rifting begins (e.g., Buck, 2007), as well as forces at the base of the lithosphere and far-field plate interactions (Ziegler and Cloetingh, 2004). ABSTRACT Continental rupture at its two extremes creates either large Rifts in the interior of continents that evolve to form large ocean basins or small and narrow marginal seas depending oceans typically last for 30 to 80 m.y. and longer before com- largely on the tectonic setting of the rift. Rupture of a conti- plete rupture of the continent and onset of sea-floor spreading. nent that creates large oceans most commonly initiates as A distinct style of rifts form along the active tectonic margins of rifts in old, cold continental lithosphere or within former continents, and these rifts more commonly form marginal seas large collisional belts in the interior of large continents, part and terranes or continental blocks or slivers that are ruptured of the process known as the Wilson Cycle (Wilson, 1966). away from their home continent. The Gulf of California and the Rupture to create narrow marginal seas commonly occurs in Baja California microplate make up one of the best examples active continental margins and results in the formation of of the latter setting and processes.
  • Patricia Persaud

    Patricia Persaud

    A bottom-driven mechanism for distributed faulting in the Gulf of California Rift Patricia Persaud1, Eh Tan2, Juan Contreras3 and Luc Lavier4 2017 GeoPRISMS Theoretical and Experimental Institute on Rift Initiation and Evolution [email protected], Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisiana 70803; 2 Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan; 3 Centro de Investigación Científca y de Educación Superior de Ensenada, Ensenada, BC, Mexico; 4 University of Texas Austin, Institute for Geophysics, Austin, TX 78712 Introduction Modeling strain partitioning and distribution of deformation in Application to the Northern Gulf Observations in the continent-ocean transition of the Gulf • Our model with an obliquity of 0.7, and linear basal velocity of California (GOC) show multiple oblique-slip faults oblique rifts boundary conditions reveals a delocalized fault pattern of distributed in a 200x70 km2 area (Fig. 4). In contrast, north contemporaneously active faults, multiple rift basins and and south of this broad pull-apart structure, major transform variable fault dips representative of faulting in the N. Gulf. faults accommodate plate motion. We propose that the FIG. 9 • The r=0.7 model is able to predict the broad geometrical mechanism for distributed faulting results from the boundary arrangement of the two Upper Delfn, Lower Delfn and conditions present in the GOC, where basal shear is Wagner basins as segmented basins with tilted fault blocks, distributed between the southernmost fault of the San and multiple oblique-slip bounding faults characteristic of Andreas system and the Ballenas Transform fault. FIG. 8 incomplete strain-partitioning. We also confrm with our We hypothesize that in oblique-extensional settings numerical results that numerous oblique-slip faults whether deformation is partitioned in a few dip-slip and accommodate slip in the study area instead of throughgoing strike-slip faults, or in numerous oblique-slip faults may large-offset transform faults.
  • Lithospheric Rupture in the Gulf of California – Salton Trough Region

    Lithospheric Rupture in the Gulf of California – Salton Trough Region

    Lithospheric Rupture in the Gulf of California – Salton Trough Region MARGINS-RCL Workshop Ensenada, Mexico, 9-13 January, 2006 ABSTRACTS http://www.rcl-cortez.wustl.edu Contents An Author Index is located in the back Seismic imaging of the transition from continental rifting to seafloor spreading, Woodlark Rift system, Papua New Guinea ………………………………………6 Rift-to-rift Drift Transition in the Gulf of California …………………………………….7 Low-angle normal faults in the northern Gulf of California extensional province: summary and implications for fault mechanics and strain partitioning ………….8 Volcanism along the eastern margin of the Salton Trough: Constraints on the kinematics of initiation of the southern San Andreas transform fault system ………………10 Numerical models of extending and rifting thickened continental crust….……………..11 Gravity Modeling and Crustal Structure of northern eastern Baja California and the western Salton Trough …………………………………………………………..12 Constraining Upper Mantle Flow Using Seismic Anisotropy & Geodynamic Modeling.13 Crustal Structure of the Southern Gulf of California, the East Pacific Rise to the Jalisco Block …………………………………………………………………………….14 Why It Is Hard to Make a Core Complex ………………………………………………15 Exotic vs. Fringing Arc Models For the Growth Of Continents: Evidence From Mesozoic Arc-Related Basins of Baja California and Western Mexico……………………16 An overview of the petrology of oceanic basement in the southern Gulf of California ...17 Seismotectonics and Upper Mantle Deformation at the Southern Basin and Range Province in Sonora,
  • Active Applicant Report Type Status Applicant Name

    Active Applicant Report Type Status Applicant Name

    Active Applicant Report Type Status Applicant Name Gaming PENDING ABAH, TYRONE ABULENCIA, JOHN AGUDELO, ROBERT JR ALAMRI, HASSAN ALFONSO-ZEA, CRISTINA ALLEN, BRIAN ALTMAN, JONATHAN AMBROSE, DEZARAE AMOROSE, CHRISTINE ARROYO, BENJAMIN ASHLEY, BRANDY BAILEY, SHANAKAY BAINBRIDGE, TASHA BAKER, GAUDY BANH, JOHN BARBER, GAVIN BARRETO, JESSE BECKEY, TORI BEHANNA, AMANDA BELL, JILL 10/1/2021 7:00:09 AM Gaming PENDING BENEDICT, FREDRIC BERNSTEIN, KENNETH BIELAK, BETHANY BIRON, WILLIAM BOHANNON, JOSEPH BOLLEN, JUSTIN BORDEWICZ, TIMOTHY BRADDOCK, ALEX BRADLEY, BRANDON BRATETICH, JASON BRATTON, TERENCE BRAUNING, RICK BREEN, MICHELLE BRIGNONI, KARLI BROOKS, KRISTIAN BROWN, LANCE BROZEK, MICHAEL BRUNN, STEVEN BUCHANAN, DARRELL BUCKLEY, FRANCIS BUCKNER, DARLENE BURNHAM, CHAD BUTLER, MALKAI 10/1/2021 7:00:09 AM Gaming PENDING BYRD, AARON CABONILAS, ANGELINA CADE, ROBERT JR CAMPBELL, TAPAENGA CANO, LUIS CARABALLO, EMELISA CARDILLO, THOMAS CARLIN, LUKE CARRILLO OLIVA, GERBERTH CEDENO, ALBERTO CENTAURI, RANDALL CHAPMAN, ERIC CHARLES, PHILIP CHARLTON, MALIK CHOATE, JAMES CHURCH, CHRISTOPHER CLARKE, CLAUDIO CLOWNEY, RAMEAN COLLINS, ARMONI CONKLIN, BARRY CONKLIN, QIANG CONNELL, SHAUN COPELAND, DAVID 10/1/2021 7:00:09 AM Gaming PENDING COPSEY, RAYMOND CORREA, FAUSTINO JR COURSEY, MIAJA COX, ANTHONIE CROMWELL, GRETA CUAJUNO, GABRIEL CULLOM, JOANNA CUTHBERT, JENNIFER CYRIL, TWINKLE DALY, CADEJAH DASILVA, DENNIS DAUBERT, CANDACE DAVIES, JOEL JR DAVILA, KHADIJAH DAVIS, ROBERT DEES, I-QURAN DELPRETE, PAUL DENNIS, BRENDA DEPALMA, ANGELINA DERK, ERIC DEVER, BARBARA
  • Bottom Water and Bottom Configuration of the Great Atlantic Deeps. (1) (2)

    Bottom Water and Bottom Configuration of the Great Atlantic Deeps. (1) (2)

    bOTTOM WATER AND bOTTOM CONFIGURATION OF THE GREAT ATLANTIC DEEPS. (1) (2). (Extract from the Results of the German Atlantic Expedition) by G e o r g WUST. The problem of the origin and distribution of bottom water has been discussed from early times, and often. This results from the fact that more abundant materials of observation exist for the bottom than for the deep layers, because measurements of bottom temperature have been taken not only by exploring vessels, but also by hydro- graphic and cable-laying ships. The remarkably low temperatures of nearly o° C. on the bottom, which were confirmed on each occasion, also early served as the principal foun­ dation of the hypothesis of the polar origin of the bottom water. The polar bottom currents are consequently members of the deep oceanic circulation, the existence of which had been deduced from the distribution of the temperature before the Challenger expedi­ tion. If it had been thought before that time that the Arctic and Antarctic currents showed roughly the same development and met at the equator, it became clear, after the Challenger and Gazelle observations, that the principal mass of the bottom waters of the great oceans comes from the Antarctic Basin ; that in the Atlantic Ocean this bottom current chiefly leads into the western trough ; and that it can still be detected in the form of a cold stream as far as the equator (in its last ramifications it even passes the equator and reaches the North Atlantic). These expeditions have also shown the value of bottom temperatures for revealing the first magnitude shapes of the ocean bottom, a value which has been proved for the Atlantic Ocean by two examples which have become classic.
  • Cedar Breaks National Monument NRCA

    Cedar Breaks National Monument NRCA

    National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Cedar Breaks National Monument Natural Resource Condition Assessment Natural Resource Report NPS/NCPN/NRR—2018/1631 ON THIS PAGE Markagunt Penstemon. Photo Credit: NPS ON THE COVER Clouds over Red Rock. Photo Credit:© Rob Whitmore Cedar Breaks National Monument Natural Resource Condition Assessment Natural Resource Report NPS/NCPN/NRR—2018/1631 Author Name(s) Lisa Baril, Kimberly Struthers, and Patricia Valentine-Darby Utah State University Department of Environment and Society Logan, Utah Editing and Design Kimberly Struthers May 2018 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service. The series supports the advancement of science, informed decision-making, and the achievement of the National Park Service mission. The series also provides a forum for presenting more lengthy results that may not be accepted by publications with page limitations. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner.
  • Kinematics and Extent of the Piemont-Liguria Basin

    Kinematics and Extent of the Piemont-Liguria Basin

    https://doi.org/10.5194/se-2020-161 Preprint. Discussion started: 8 October 2020 c Author(s) 2020. CC BY 4.0 License. Kinematics and extent of the Piemont-Liguria Basin – implications for subduction processes in the Alps Eline Le Breton1, Sascha Brune2,3, Kamil Ustaszewski4, Sabin Zahirovic5, Maria Seton5, R. Dietmar Müller5 5 1Department of Earth Sciences, Freie Universität Berlin, Germany 2Geodynamic Modelling Section, German Research Centre for Geosciences, GFZ Potsdam, Germany 3Institute of Geosciences, University of Potsdam, Potsdam, Germany 4Institute for Geological Sciences, Friedrich-Schiller-Universität Jena, Germany 10 5EarthByte Group, School of Geosciences, The University of Sydney, NSW 2006, Australia Correspondence to: Eline Le Breton ([email protected]) Abstract. Assessing the size of a former ocean, of which only remnants are found in mountain belts, is challenging but crucial to understand subduction and exhumation processes. Here we present new constraints on the opening and width of the Piemont- Liguria (PL) Ocean, known as the Alpine Tethys together with the Valais Basin. We use a regional tectonic reconstruction of 15 the Western Mediterranean-Alpine area, implemented into a global plate motion model with lithospheric deformation, and 2D thermo-mechanical modelling of the rifting phase to test our kinematic reconstructions for geodynamic consistency. Our model fits well with independent datasets (i.e. ages of syn-rift sediments, rift-related fault activity and mafic rocks) and shows that the PL Basin opened in four stages: (1) Rifting of the proximal continental margin in Early Jurassic (200-180 Ma), (2) Hyper- extension of the distal margin in Early-Middle Jurassic (180-165 Ma), (3) Ocean-Continent Transition (OCT) formation with 20 mantle exhumation and MORB-type magmatism in Middle-Late Jurassic (165-154 Ma), (4) Break-up and “mature” oceanic spreading mostly in Late Jurassic (154-145 Ma).
  • Bathymetry and Active Geological Structures in the Upper Gulf of California Luis G

    Bathymetry and Active Geological Structures in the Upper Gulf of California Luis G

    BOLETÍN DE LA SOCIEDAD GEOLÓ G ICA MEXICANA VOLU M EN 61, NÚ M . 1, 2009 P. 129-141 Bathymetry and active geological structures in the Upper Gulf of California Luis G. Alvarez1*, Francisco Suárez-Vidal2, Ramón Mendoza-Borunda2, Mario González-Escobar3 1 Departamento de Oceanografía Física, División de Oceanología. 2 Departamento de Geología, División de Ciencias de la Tierra. 3 Departamento de Geofísica Aplicada, División de Ciencias de la Tierra. Centro de Investigación Científica y de Educación Superior de Ensenada, B.C. Km 107 carretera Tijuana-Ensenada, Ensenada, Baja California, México, 22860. * Corresponding author: E-mail: [email protected] Abstract Bathymetric surveys made between 1994 and 1998 in the Upper Gulf of California revealed that the bottom relief is dominated by narrow, up to 50 km long, tidal ridges and intervening troughs. These sedimentary linear features are oriented NW-SE, and run across the shallow shelf to the edge of Wagner Basin. Shallow tidal ridges near the Colorado River mouth are proposed to be active, while segments in deeper water are considered as either moribund or in burial stage. Superposition of seismic swarm epicenters and a seismic reflection section on bathymetric features indicate that two major ridge-troughs structures may be related to tectonic activity in the region. Off the Sonora coast the alignment and gradient of the isobaths matches the extension of the Cerro Prieto Fault into the Gulf. A similar gradient can be seen over the west margin of the Wagner Basin, where in 1970 a seismic swarm took place (Thatcher and Brune, 1971) overlapping with a prominent ridge-trough structure in the middle of the Upper Gulf.