11482nam 2200661Ia 450 991081249590332120200520144314.01-280-21277-297866102127740-309-54327-40-585-14400-1(CKB)111004366658502(OCoLC)427404659(CaPaEBR)ebrary10062759(SSID)ssj0000197762(PQKBManifestationID)11189641(PQKBTitleCode)TC0000197762(PQKBWorkID)10162416(PQKB)10856378(MiAaPQ)EBC3376919(Au-PeEL)EBL3376919(CaPaEBR)ebr10062759(CaONFJC)MIL21277(OCoLC)923266967(EXLCZ)9911100436665850219891211d1989 ua 0engurcn|||||||||txtrdacontentcrdamediacrrdacarrierMargins a research initiative for interdisciplinary studies of processes attending lithospheric extension and convergence : proceedings of a workshop sponsored by the National Research Council, Beckman Center, Irvine, California, November 20-23, 1988 /Continental Margins Committee, Ocean Studies Board, Commission on Physical Sciences, Mathematics, and Resources, National Research Council1st ed.Washington, D.C. National Academy Press19891 online resource (295 pages) illustrationsBibliographic Level Mode of Issuance: Monograph0-309-04188-0 Includes bibliographical references.Margins: A Research Initiative for Interdisciplinary Studies of Processes Attending Lithospheric Extension and Convergence -- Copyright -- PREFACE -- Contents -- PART I REPORT OF THE CONTINENTAL MARGINS WORKSHOP -- Executive Summary -- OVERVIEW -- Mechanics of Faulting -- Fluid Flow -- Growth and Modification of Continental Crust -- Depositional Systems at the Edge of the Continents -- DEVELOPMENT OF A SCIENCE PLAN -- Formation of a Margins Initiative Committee -- Organization of Workshops -- 1 Introduction -- IMPETUS FOR THE WORKSHOP -- ORGANIZATION AND SUPPORT OF THE WORKSHOP -- Passive Margins -- Active Margins -- CHARGES TO THE WORKING GROUPS -- 2 Results of the Workshop -- MARGIN PROCESSES: A NEW RATIONALE FOR RESEARCH INTO LITHOSPHERIC CONVERGENCE AND DIVERGENCE -- Divergent Margins -- Convergent And Translational Margins -- Deformational Processes -- Magmatic Processes -- Fluid Flow -- Sedimentation Processes -- Mantle Dynamics -- FUTURE DIRECTIONS FOR RESEARCH ON MARGIN PROCESSES: REQUIREMENTS FOR SUCCESS -- Communication and Collaboration Among Scientists -- Databases -- Computational Facilities -- Scientific Drilling -- Seismic Facilities -- Chemical Analytical Facilities -- Theoretical and Computational Studies -- 3 Components of A Margins Initiative -- A NEW APPROACH FOR MARGINS RESEARCH -- A MARGINS INITIATIVE COMMITTEE -- PLANNING WORKSHOPS -- DRAFTING A SCIENTIFIC PLAN -- PART II REPORTS OF THE WORKING GROUPS -- 4 Passive Margins: Group 1 Mechanics of Rifting and Associated Magmatism -- PREAMBLE -- Surface Geological Mapping in the Basin and Range Province -- Deep Seismic Reflection Profiling On Extended Continental Lithosphere and Laboratory Measurements of Lithospheric Materials -- Shallow Marine Reflection Profiling and Surface Geologic Studies of the East African Rift System.Marine Geophysical Studies of the Deep Structure of Passive Margins in the Central and North Atlantic Oceans -- Theoretical Modeling of Subsidence and Thermal History In Sedimentary Basins and the Lithosphere a Continuum -- Isotope And Trace Element Analysis of Rift Volcanics and Xenoliths -- THE SINGLE MOST IMPORTANT SCIENTIFIC OBJECTIVE -- NEEDED STUDIES -- Determine the Distribution of Three-Dimensional Strain in the Lithosphere -- Low-Angle Normal Faulting in the Crust -- The Interplay Between Extension and the Rheological Stratification of the Lithosphere -- Structural and Magmatic Segmentation of Rifts in the Context of the Mechanics of Rifting and Heterogeneities of the Lithosphe -- Determine the Causes of Compositional, Temporal, and Spatial Variations in Magmatism and Degassing -- Vertical and Lateral Magmatic Transport -- The Transition From Rift to Ridge Magmatism -- Mobility of the Crust-Mantle Boundary During Rifting -- Determine the Cause for Spatial and Temporal Variability of Uplift and Subsidence in Rift Systems -- The Timing and Rate of Vertical Motion -- Isostasy During and After Rifting -- Uplift and Subsidence as an Independent Constraint on the Overall Structure of the Rift -- The Interplay Between Rift Structure, Topography, Erosion, and Deposition -- 5 Passive Margins: Group 2 Rift and Passive Margin Basins- The Sedimentary Record -- PREAMBLE -- BACKGROUND -- Scientific -- Economic -- Biospheric -- THE SINGLE MOST IMPORTANT SCIENTIFIC OBJECTIVE -- The Specific Processes Involved -- Origin of Stratification -- Origin of Stratigraphic Sequences -- Stratigraphic Documentation of Global Synergisms -- Improved Temporal Resolution -- Critical Problems -- Stratigraphic Problems -- Processes -- Events -- NEEDED STUDIES -- Kinds of Information -- Data Collection Methods and Tools -- Laboratory, Theoretical, and Numerical Developments.Dynamical Sediment Flux and Accumulation Models -- Backstripping Models -- Seismic Expression of Stratal Geometries -- Measurement Capabilities Needed -- STRATEGIES REQUIRED TO ACHIEVE THE GOALS -- 6 Passive Margins Group 3 Divergent Continental Margins-Post-Rifting Internal Processes -- SUMMARY -- BACKGROUND -- THE SINGLE MOST IMPORTANT SCIENTIFIC OBJECTIVE -- Processes Involved -- Critical Problems -- NEEDED STUDIES -- Obtaining Snapshots of Fluid and Chemical Fluxes in Divergent Margin Basins -- Fluid Seeps on Flanks and Toes of Divergent Margins -- Geopressured Fluid Flow -- Heat Flow -- Determining the Cumulative Effects of Fluid and Chemical Fluxes in Divergent Margin Basins -- Diagenetic Cements -- Gas Hydrates -- Hydrocarbon Maturation -- Developing Integrated Models to Simulate Fluid-Chemical Processes in Divergent Margins -- Local Models -- The Integrated Process Model -- STRATEGY REQUIRED TO ACHIEVE GOALS -- BROADER IMPLICATIONS -- Selected Bibliography -- 7 Active Margins: Group 1 Dynamics of Short-Term Deformation At Active Margins -- THE SINGLE MOST IMPORTANT SCIENTIFIC OBJECTIVE -- THREE MAJOR AREAS FOR INVESTIGATION -- What Controls Aseismic Deformation and the Recurrence Characteristics and Locations of Catastrophic Earthquakes? -- What Controls Accretion, Nonaccretion, and Erosion of the Upper Plate at Convergent Margins? -- What Determines the Partitioning of Deformation In Plate-Boundary Zones? -- NEEDED STUDIES -- Geometry of the Downgoing Plate -- Structures, Geodetics, and Seismicity of Subduction Margins -- Numerical Modeling -- Enhanced Geophysical Instrumentation -- Submarine and Rapidly Deployed Geodetics -- Ocean-Bottom Seismometers -- Measurements of Stress and Deep Structures -- Rheological Studies -- 8 Active Margins: Group 2 Geologic Evolution of Active Continental Margins.THE SINGLE MOST IMPORTANT SCIENTIFIC OBJECTIVE -- How are Terranes Formed, Moved, and Accreted? -- What are the Consequences of Changes in Plate Motion for Active Plate Boundaries? -- What Controls Vertical Motions in the Forearc Region of Convergent Margins? -- Specific Problems -- What Controls Arc Rifting and the Development of Backarc Basins? -- What Causes the Initiation of Subduction? -- NEEDED STUDIES -- Mapping, Paleomagnetics, Petrology, and Geochemistry of Terranes -- Cross-Disciplinary Studies of Rifting and Backarc Basins -- Geodetic and Geomorphic Studies of Propagating Subduction -- 9 Active Margins: Group 3 Mass and Chemical Transfer -- INTRODUCTION -- Melting Pot of the Earth: Crustal Formation and Modification at Active Margins -- CRITICAL PROBLEMS -- Chemical Variability of Input from the Subducting Plate -- Mass Transfer Across Plate Boundaries -- Mantle Wedge Processes -- Crustal Processes -- Chemical Variability of the Output: Geochemistry of Magmas and Fluids at Active Margins -- Episodicity of Volcanism: Reflection of a Nonlinear System -- NEEDED STUDIES -- 10 Supplementary Note on Rock Mechanics Problems at Active Margins -- LABORATORY EXPERIMENTS -- CONDITIONS IN CONTINENTAL MARGINS -- PARADOX OF STRESS MAGNITUDES ON FAULTS -- PART III BACKGROUND PAPERS -- Contents -- ACTIVE CONTINENTAL MARGINS MECHANICS OF PLATE MOTION -- MECHANICS, KINEMATICS, AND DEFORMATION MODES AT CONVERGENT MARGINS -- Introduction -- Selected Problems -- Future Research Directions -- References -- Figure Captions -- DRIVING FORCES: SLAB SUBDUCTION AND MANTLE CONVECTION -- Introduction -- State of Current Knowledge -- Empirical -- Observations -- Models -- Key Questions -- New Observations, Experiments, and Models -- Seismology -- Geodesy -- Mineral Physics -- Numerical Modeling -- Bibliography -- FIGURE CAPTIONS.ACTIVE CONTINENTAL MARGINS EGEOLOGIC EVOLUTION OF ACTIVE CONTINENTAL MARGINS -- INITIATION OF SUBDUCTION -- Introduction -- State of Knowledge -- Outstanding Questions -- Targets for Future Research -- 1. Conventional Oceanographic Studies -- 2. On-land studies of ophiolites and other emergent forearcs -- 3. Special Projects -- References -- INTRAOCEANIC CONVERGENT MARGINS -- Introduction -- Magmatism -- Structure and Stratigraphy -- Fluids and Thermal Regime -- Methods for Studying These Margins -- Selected References -- COLLISION OF SEAMOUNTS, RIDGES, AND CONTINENTAL FRAGMENTS: THEIR EFFECTS ON CONVERGENT MARGINS -- Some Tectonic Processes Accompanying Collision -- Questions -- References -- Figure Caption -- ACTIVE CONTINENTAL MARGINS MASS AND CHEMICAL TRANSFER -- MASS FLUX AND CRUSTAL EVOLUTION AT CONVERGENT MARGINS -- I. Introduction: the Present Crust-Mantle System -- II. Mass Flux at Convergent Margins -- a) Global Overview -- b) Input-Output Analysis Of Subduction Process (S-Process) Crustal Recycling -- c) Regional Variability -- III. Crustal Evolution -- a) Coupling of Mantle-Crust Evolution -- b) Crustal Additions, Crustal Composition, and Lower Crustal Delamination -- Outstanding Questions -- a) Processes of Mass Transfer -- b) Mass Flux and the Geological Record -- c) Relation of Mantle Heterogeneity to Plate Convergence -- References -- PASSIVE CONTINENTAL MARGINS MECHANICS OF RIFTING OF THE LITHOSPHERE -- COMMENTS ON RIFTING AND PASSIVE MARGIN EVOLUTION IN LIGHT OF SOME RECENT STUDIES -- References -- IGNEOUS PROCESSES AND THE EVOLUTION OF RIFTED CONTINENTAL MARGINS -- Some Suggestions for Future Research -- References -- PASSIVE CONTINENTAL MARGINS RIFT AND PASSIVE MARGIN BASINS - THE SEDIMENTARY RECORD -- INVESTIGATING THE SEDIMENTARY RECORD: SEQUENCE STRATIGRAPHY-THE RECORD OF TECTONISM AND THE GLOBAL OCEAN ENVIRONMENT.Introduction.Plate tectonicsCongressesContinental marginsCongressesEarthCrustCongressesPlate tectonicsContinental margins551.1/36National Research Council (U.S.).Continental Margins Committee.MiAaPQMiAaPQMiAaPQBOOK9910812495903321Margins1957656UNINA