The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Nicholas H Hinz - One of the best experts on this subject based on the ideXlab platform.
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kinematics of the Northern walker lane an incipient transform fault along the pacific North American Plate boundary
Geology, 2005Co-Authors: James E Faulds, Christopher D Henry, Nicholas H HinzAbstract:In the western Great Basin of North America, a system of dextral faults accommodates 15%–25% of the Pacific–North American Plate motion. The Northern Walker Lane in Northwest Nevada and Northeast California occupies the Northern terminus of this system. This young evolving part of the Plate boundary offers insight into how strike-slip fault systems develop and may reflect the birth of a transform fault. A belt of overlapping, left-stepping dextral faults dominates the Northern Walker Lane. Offset segments of a W-trending Oligocene paleovalley suggest ∼20–30 km of cumulative dextral slip beginning ca. 9–3 Ma. The inferred long-term slip rate of ∼2–10 mm/yr is compatible with global positioning system observations of the current strain field. We interpret the left-stepping faults as macroscopic Riedel shears developing above a nascent lithospheric-scale transform fault. The strike-slip faults end in arrays of ∼N-striking normal faults, suggesting that dextral shear diffuses into extension in the Great Basin. Coeval extension and dextral shear have induced slight counterclockwise fault-block rotations, which may ultimately rotate Riedel shears toward the main shear zone at depth, thus facilitating development of a throughgoing strike-slip fault.
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Kinematics of the Northern Walker Lane: An incipient transform fault along the Pacific–North American Plate boundary
Geology, 2005Co-Authors: James E Faulds, Christopher D Henry, Nicholas H HinzAbstract:In the western Great Basin of North America, a system of dextral faults accommodates 15%–25% of the Pacific–North American Plate motion. The Northern Walker Lane in Northwest Nevada and Northeast California occupies the Northern terminus of this system. This young evolving part of the Plate boundary offers insight into how strike-slip fault systems develop and may reflect the birth of a transform fault. A belt of overlapping, left-stepping dextral faults dominates the Northern Walker Lane. Offset segments of a W-trending Oligocene paleovalley suggest ∼20–30 km of cumulative dextral slip beginning ca. 9–3 Ma. The inferred long-term slip rate of ∼2–10 mm/yr is compatible with global positioning system observations of the current strain field. We interpret the left-stepping faults as macroscopic Riedel shears developing above a nascent lithospheric-scale transform fault. The strike-slip faults end in arrays of ∼N-striking normal faults, suggesting that dextral shear diffuses into extension in the Great Basin. Coeval extension and dextral shear have induced slight counterclockwise fault-block rotations, which may ultimately rotate Riedel shears toward the main shear zone at depth, thus facilitating development of a throughgoing strike-slip fault.
Jason B. Saleeby - One of the best experts on this subject based on the ideXlab platform.
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Transcontinental geologic cross section of the North American Plate near 36° latitude; Part I, Western U.S. from the Pacific oceanic crust to the Mid-Continent
2009Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:The American Geological Institute, in dedication to Marcus E. Milling, is producing a geologic cross section across the southern United States near latitude 36°. The cross section extends from the eastern to the western margin of the North American Plate and will provide an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The cross section will be in two sheets (Eastern and Western U.S.). Each will consist of an annotated 1:2M-scale geological cross section useful for K-12, the general public, introductory college geology classes, and researchers. An oblique DEM at the top of the cross section will add a 3D component. The DEM will overlie a cross section with 4:1 vertical exaggeration that will portray the geology to depths of 150 km which, in turn will overlie a 1:1 cross section extending to 250 km. The western half of the cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. In this region, Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. The scientific “punchline” for this part of the cross section is that the western North American Plate is dynamically uplifting and tectonically active because of interactions with flowing mantle near its base. Both halves of the cross section emphasize that North America provides a field laboratory for understanding the structure and evolution of continental Plates. The continent is profoundly segmented because of its >4 billion year history, and has been built progressively by collision of continental fragments and oceanic terranes to the existing continental nucleus. The overall theme for North America (and for all continents) involves a history where active Plate tectonic processes are superimposed on a heterogeneous existing structure developed during their billion-year evolution.
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transcontinental geologic cross section of the North American Plate near 36 latitude part i western u s from the pacific oceanic crust to the mid continent
2009Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:The American Geological Institute, in dedication to Marcus E. Milling, is producing a geologic cross section across the southern United States near latitude 36°. The cross section extends from the eastern to the western margin of the North American Plate and will provide an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The cross section will be in two sheets (Eastern and Western U.S.). Each will consist of an annotated 1:2M-scale geological cross section useful for K-12, the general public, introductory college geology classes, and researchers. An oblique DEM at the top of the cross section will add a 3D component. The DEM will overlie a cross section with 4:1 vertical exaggeration that will portray the geology to depths of 150 km which, in turn will overlie a 1:1 cross section extending to 250 km. The western half of the cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. In this region, Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. The scientific “punchline” for this part of the cross section is that the western North American Plate is dynamically uplifting and tectonically active because of interactions with flowing mantle near its base. Both halves of the cross section emphasize that North America provides a field laboratory for understanding the structure and evolution of continental Plates. The continent is profoundly segmented because of its >4 billion year history, and has been built progressively by collision of continental fragments and oceanic terranes to the existing continental nucleus. The overall theme for North America (and for all continents) involves a history where active Plate tectonic processes are superimposed on a heterogeneous existing structure developed during their billion-year evolution.
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Transcontinental geologic cross section of the North American Plate near 36° latitude; Part II, Atlantic Ocean crust to the Mid-Continent
2009Co-Authors: Robert D. Hatcher, William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Rodger E. Denison, Cindy M. Martinez, G. R. Keller, Zorka SaleebyAbstract:The American Geological Institute Geologic Cross Section of the North American Plate, in memory of Marcus E. Milling, has produced a technical cross section across the continent for researchers, and will produce a geologic section useful for K-12 education, the general public, and introductory college geology classes, to provide better understanding of the tectonic processes that produced southern half of our continent. The technical product consists of the cross section at a 4:1 vertical exaggeration to 150 km, and a section at 1:1 that portrays the geology to depths of 250 km, with an oblique DEM, adding a 3D component. The E segment extends westward from 67° to 99° W, from Atlantic Ocean crust E of the Blake Spur magnetic anomaly (BSMA) across the East Coast magnetic anomaly (ECMA) and modern continental margin; across the Appalachians, the Nashville dome, Mississippi Embayment (ME) and into the Mid-Continent. The modern continental margin records the Mesozoic rift-to-drift transition following breakup of Pangea, which includes the enigmatic BSMA (abandoned ridge segment?) and ECMA (mafic intrusions formed by decompression melting as Africa separated from Laurentia?); the southern Appalachians accreted through three Paleozoic orogenies to the Neoproterozoic-early Paleozoic Laurentian margin, and the subsurface Grenville front, recording two complete Wilson cycles; then crosses much of the Mid-Continent, which records accretion of the Mid-Proterozoic Mazatzal and Yavapai arcs and late plutons. The Mid-Continent component illustrates cratonic stability despite major Phanerozoic tectonic events along its southern and eastern margins. Relatively thin Phanerozoic cover characterizes the continental interior, with local thickening across the ME and Reelfoot rift. The E section also crosses the New Madrid and East Tennessee seismic zones, the two most active in the eastern U.S. Recorded here is a history and crustal formation processes spanning almost 2 Ga, with normal-thickness crust (30-40 km) beneath the E segment, except beneath the topographically high southern Appalachians (~50 km), suggesting the eastern U.S. highlands may be explained by local isostatic imbalance.
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transcontinental geologic cross section of the North American Plate near 36 latitude part ii atlantic ocean crust to the mid continent
2009Co-Authors: Robert D. Hatcher, William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Rodger E. Denison, Cindy M. Martinez, G. R. Keller, Zorka SaleebyAbstract:The American Geological Institute Geologic Cross Section of the North American Plate, in memory of Marcus E. Milling, has produced a technical cross section across the continent for researchers, and will produce a geologic section useful for K-12 education, the general public, and introductory college geology classes, to provide better understanding of the tectonic processes that produced southern half of our continent. The technical product consists of the cross section at a 4:1 vertical exaggeration to 150 km, and a section at 1:1 that portrays the geology to depths of 250 km, with an oblique DEM, adding a 3D component. The E segment extends westward from 67° to 99° W, from Atlantic Ocean crust E of the Blake Spur magnetic anomaly (BSMA) across the East Coast magnetic anomaly (ECMA) and modern continental margin; across the Appalachians, the Nashville dome, Mississippi Embayment (ME) and into the Mid-Continent. The modern continental margin records the Mesozoic rift-to-drift transition following breakup of Pangea, which includes the enigmatic BSMA (abandoned ridge segment?) and ECMA (mafic intrusions formed by decompression melting as Africa separated from Laurentia?); the southern Appalachians accreted through three Paleozoic orogenies to the Neoproterozoic-early Paleozoic Laurentian margin, and the subsurface Grenville front, recording two complete Wilson cycles; then crosses much of the Mid-Continent, which records accretion of the Mid-Proterozoic Mazatzal and Yavapai arcs and late plutons. The Mid-Continent component illustrates cratonic stability despite major Phanerozoic tectonic events along its southern and eastern margins. Relatively thin Phanerozoic cover characterizes the continental interior, with local thickening across the ME and Reelfoot rift. The E section also crosses the New Madrid and East Tennessee seismic zones, the two most active in the eastern U.S. Recorded here is a history and crustal formation processes spanning almost 2 Ga, with normal-thickness crust (30-40 km) beneath the E segment, except beneath the topographically high southern Appalachians (~50 km), suggesting the eastern U.S. highlands may be explained by local isostatic imbalance.
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Geologic Cross Section of the North American Plate near 36° Latitude, Part I: Western U.S. from the Pacific Oceanic Crust to the Mid-Continent
2008Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:A geologic cross section across the southern United States near latitude 36° provides an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The American Geological Institute, in dedication to Marcus E. Milling, will produce an annotated 1:1 M-scale technical cross section across the continent useful to researchers, and a 1:2 M-scale geological cross section useful for K-12, the general public, and introductory college geology classes. The visual product will consist of an oblique DEM, to add a 3D component, along with the cross section at 4:1 vertical exaggeration that will portray the geology to depths of 250 km. The cross section extends from the eastern to the western margin of the North American Plate. The western half consists of a tectonically active domain in which Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. This wide deforming Plate margin domain provides a field laboratory for understanding the structure and evolution of continental Plates. The western segment of the GeCSNAP cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. A theme of the cross section is dynamic mantle flow under the western U.S. where lithosphere is sinking beneath the Sierra Nevada and asthenosphere is upwelling in the Basin and Range, near the western edge of the Colorado Plateau, and in the Rio Grande rift.
David M. Tralli - One of the best experts on this subject based on the ideXlab platform.
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Variation of seismic slip in the Gulf of California and the possible effect on geodetic measurements of Pacific‐North American Plate motion
Journal of Geophysical Research, 1992Co-Authors: Fumiko Tajima, David M. TralliAbstract:The Gulf of California is a unique tectonic transition zone which progresses from an oceanic ridge-transform system at the mouth of the gulf to a predominantly continental transform system in southern California. Slip rates estimated from seismic moment data amount to about 17 to 30% of the accumulated tectonic slip in the gulf predicted by the NUVEL-1 Plate motion model, even after accounting for the transition in crustal structure. The seismic to tectonic slip ratios also appear to increase slightly from south to North. This trend in the seismic moment release may reflect changes in the accommodation of Pacific-North American Plate motion along the gulf which can be examined geodetically. On the other hand, geodetic measurements of the relative Plate motion can be disturbed by short-term effects associated with episodic seismicity. To assess these effects, the surface displacements due to typical transform events in the gulf are estimated using a simple dislocation model. The results of this numerical calculation suggest that if a large transform event (M0 ∼ 1.5 × 1026 dyne cm) were to occur within 100 to 200 km of a geodetic baseline, for example one comprised in the GEOMEX Global Positioning System network across the southern gulf, the relative distance measurements could be affected by up to 15 mm. This is marginally at the error level of a few millimeters plus 2 parts in 108 of baseline length for GEOMEX measurements, which thus are sensitive only to the far-field displacement along the Plate boundary (over baselines of a few hundred kilometers in length).
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variation of seismic slip in the gulf of california and the possible effect on geodetic measurements of pacific North American Plate motion
Journal of Geophysical Research, 1992Co-Authors: Fumiko Tajima, David M. TralliAbstract:The Gulf of California is a unique tectonic transition zone which progresses from an oceanic ridge-transform system at the mouth of the gulf to a predominantly continental transform system in southern California. Slip rates estimated from seismic moment data amount to about 17 to 30% of the accumulated tectonic slip in the gulf predicted by the NUVEL-1 Plate motion model, even after accounting for the transition in crustal structure. The seismic to tectonic slip ratios also appear to increase slightly from south to North. This trend in the seismic moment release may reflect changes in the accommodation of Pacific-North American Plate motion along the gulf which can be examined geodetically. On the other hand, geodetic measurements of the relative Plate motion can be disturbed by short-term effects associated with episodic seismicity. To assess these effects, the surface displacements due to typical transform events in the gulf are estimated using a simple dislocation model. The results of this numerical calculation suggest that if a large transform event (M0 ∼ 1.5 × 1026 dyne cm) were to occur within 100 to 200 km of a geodetic baseline, for example one comprised in the GEOMEX Global Positioning System network across the southern gulf, the relative distance measurements could be affected by up to 15 mm. This is marginally at the error level of a few millimeters plus 2 parts in 108 of baseline length for GEOMEX measurements, which thus are sensitive only to the far-field displacement along the Plate boundary (over baselines of a few hundred kilometers in length).
Robert D. Hatcher - One of the best experts on this subject based on the ideXlab platform.
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Transcontinental geologic cross section of the North American Plate near 36° latitude; Part I, Western U.S. from the Pacific oceanic crust to the Mid-Continent
2009Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:The American Geological Institute, in dedication to Marcus E. Milling, is producing a geologic cross section across the southern United States near latitude 36°. The cross section extends from the eastern to the western margin of the North American Plate and will provide an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The cross section will be in two sheets (Eastern and Western U.S.). Each will consist of an annotated 1:2M-scale geological cross section useful for K-12, the general public, introductory college geology classes, and researchers. An oblique DEM at the top of the cross section will add a 3D component. The DEM will overlie a cross section with 4:1 vertical exaggeration that will portray the geology to depths of 150 km which, in turn will overlie a 1:1 cross section extending to 250 km. The western half of the cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. In this region, Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. The scientific “punchline” for this part of the cross section is that the western North American Plate is dynamically uplifting and tectonically active because of interactions with flowing mantle near its base. Both halves of the cross section emphasize that North America provides a field laboratory for understanding the structure and evolution of continental Plates. The continent is profoundly segmented because of its >4 billion year history, and has been built progressively by collision of continental fragments and oceanic terranes to the existing continental nucleus. The overall theme for North America (and for all continents) involves a history where active Plate tectonic processes are superimposed on a heterogeneous existing structure developed during their billion-year evolution.
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transcontinental geologic cross section of the North American Plate near 36 latitude part i western u s from the pacific oceanic crust to the mid continent
2009Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:The American Geological Institute, in dedication to Marcus E. Milling, is producing a geologic cross section across the southern United States near latitude 36°. The cross section extends from the eastern to the western margin of the North American Plate and will provide an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The cross section will be in two sheets (Eastern and Western U.S.). Each will consist of an annotated 1:2M-scale geological cross section useful for K-12, the general public, introductory college geology classes, and researchers. An oblique DEM at the top of the cross section will add a 3D component. The DEM will overlie a cross section with 4:1 vertical exaggeration that will portray the geology to depths of 150 km which, in turn will overlie a 1:1 cross section extending to 250 km. The western half of the cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. In this region, Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. The scientific “punchline” for this part of the cross section is that the western North American Plate is dynamically uplifting and tectonically active because of interactions with flowing mantle near its base. Both halves of the cross section emphasize that North America provides a field laboratory for understanding the structure and evolution of continental Plates. The continent is profoundly segmented because of its >4 billion year history, and has been built progressively by collision of continental fragments and oceanic terranes to the existing continental nucleus. The overall theme for North America (and for all continents) involves a history where active Plate tectonic processes are superimposed on a heterogeneous existing structure developed during their billion-year evolution.
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Transcontinental geologic cross section of the North American Plate near 36° latitude; Part II, Atlantic Ocean crust to the Mid-Continent
2009Co-Authors: Robert D. Hatcher, William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Rodger E. Denison, Cindy M. Martinez, G. R. Keller, Zorka SaleebyAbstract:The American Geological Institute Geologic Cross Section of the North American Plate, in memory of Marcus E. Milling, has produced a technical cross section across the continent for researchers, and will produce a geologic section useful for K-12 education, the general public, and introductory college geology classes, to provide better understanding of the tectonic processes that produced southern half of our continent. The technical product consists of the cross section at a 4:1 vertical exaggeration to 150 km, and a section at 1:1 that portrays the geology to depths of 250 km, with an oblique DEM, adding a 3D component. The E segment extends westward from 67° to 99° W, from Atlantic Ocean crust E of the Blake Spur magnetic anomaly (BSMA) across the East Coast magnetic anomaly (ECMA) and modern continental margin; across the Appalachians, the Nashville dome, Mississippi Embayment (ME) and into the Mid-Continent. The modern continental margin records the Mesozoic rift-to-drift transition following breakup of Pangea, which includes the enigmatic BSMA (abandoned ridge segment?) and ECMA (mafic intrusions formed by decompression melting as Africa separated from Laurentia?); the southern Appalachians accreted through three Paleozoic orogenies to the Neoproterozoic-early Paleozoic Laurentian margin, and the subsurface Grenville front, recording two complete Wilson cycles; then crosses much of the Mid-Continent, which records accretion of the Mid-Proterozoic Mazatzal and Yavapai arcs and late plutons. The Mid-Continent component illustrates cratonic stability despite major Phanerozoic tectonic events along its southern and eastern margins. Relatively thin Phanerozoic cover characterizes the continental interior, with local thickening across the ME and Reelfoot rift. The E section also crosses the New Madrid and East Tennessee seismic zones, the two most active in the eastern U.S. Recorded here is a history and crustal formation processes spanning almost 2 Ga, with normal-thickness crust (30-40 km) beneath the E segment, except beneath the topographically high southern Appalachians (~50 km), suggesting the eastern U.S. highlands may be explained by local isostatic imbalance.
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transcontinental geologic cross section of the North American Plate near 36 latitude part ii atlantic ocean crust to the mid continent
2009Co-Authors: Robert D. Hatcher, William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Rodger E. Denison, Cindy M. Martinez, G. R. Keller, Zorka SaleebyAbstract:The American Geological Institute Geologic Cross Section of the North American Plate, in memory of Marcus E. Milling, has produced a technical cross section across the continent for researchers, and will produce a geologic section useful for K-12 education, the general public, and introductory college geology classes, to provide better understanding of the tectonic processes that produced southern half of our continent. The technical product consists of the cross section at a 4:1 vertical exaggeration to 150 km, and a section at 1:1 that portrays the geology to depths of 250 km, with an oblique DEM, adding a 3D component. The E segment extends westward from 67° to 99° W, from Atlantic Ocean crust E of the Blake Spur magnetic anomaly (BSMA) across the East Coast magnetic anomaly (ECMA) and modern continental margin; across the Appalachians, the Nashville dome, Mississippi Embayment (ME) and into the Mid-Continent. The modern continental margin records the Mesozoic rift-to-drift transition following breakup of Pangea, which includes the enigmatic BSMA (abandoned ridge segment?) and ECMA (mafic intrusions formed by decompression melting as Africa separated from Laurentia?); the southern Appalachians accreted through three Paleozoic orogenies to the Neoproterozoic-early Paleozoic Laurentian margin, and the subsurface Grenville front, recording two complete Wilson cycles; then crosses much of the Mid-Continent, which records accretion of the Mid-Proterozoic Mazatzal and Yavapai arcs and late plutons. The Mid-Continent component illustrates cratonic stability despite major Phanerozoic tectonic events along its southern and eastern margins. Relatively thin Phanerozoic cover characterizes the continental interior, with local thickening across the ME and Reelfoot rift. The E section also crosses the New Madrid and East Tennessee seismic zones, the two most active in the eastern U.S. Recorded here is a history and crustal formation processes spanning almost 2 Ga, with normal-thickness crust (30-40 km) beneath the E segment, except beneath the topographically high southern Appalachians (~50 km), suggesting the eastern U.S. highlands may be explained by local isostatic imbalance.
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Geologic Cross Section of the North American Plate near 36° Latitude, Part I: Western U.S. from the Pacific Oceanic Crust to the Mid-Continent
2008Co-Authors: William R. Muehlberger, Karl E. Karlstrom, Jason B. Saleeby, Zorka Saleeby, Rodger E. Denison, Cynthia Martinez, Robert D. HatcherAbstract:A geologic cross section across the southern United States near latitude 36° provides an up-to-date working model for the structure of the North American Plate and its interactions with the upper mantle asthenosphere. The American Geological Institute, in dedication to Marcus E. Milling, will produce an annotated 1:1 M-scale technical cross section across the continent useful to researchers, and a 1:2 M-scale geological cross section useful for K-12, the general public, and introductory college geology classes. The visual product will consist of an oblique DEM, to add a 3D component, along with the cross section at 4:1 vertical exaggeration that will portray the geology to depths of 250 km. The cross section extends from the eastern to the western margin of the North American Plate. The western half consists of a tectonically active domain in which Plate boundary deformation is inducing and interacting with a complex intraPlate deformational field in a 1000-km-wide uplifted orogenic Plateau that extends as far east as the Great Plains. This wide deforming Plate margin domain provides a field laboratory for understanding the structure and evolution of continental Plates. The western segment of the GeCSNAP cross section extends from the coastal Franciscan accretionary complex, across the Salinia forearc microPlate, the San Andreas fault, the Cretaceous forearc basin, the Sierra Nevada Mesozoic magmatic arc, the eastern California shear zone of the Basin and Range province, the Colorado Plateau, the Rio Grand rift, the Rocky Mountains, and the western Great Plains. A theme of the cross section is dynamic mantle flow under the western U.S. where lithosphere is sinking beneath the Sierra Nevada and asthenosphere is upwelling in the Basin and Range, near the western edge of the Colorado Plateau, and in the Rio Grande rift.
Shinichi Miyazaki - One of the best experts on this subject based on the ideXlab platform.
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Plate convergence and long term crustal deformation in central japan
Geophysical Research Letters, 2001Co-Authors: Kosuke Heki, Shinichi MiyazakiAbstract:Surveys by continuous Global Positioning System in and around Japan revealed that the Amurian Plate collides with the North American Plate in central Japan by ∼2 cm/yr. Long-term crustal deformation seems to be influenced mainly by this collision although subduction of oceanic Plates governs short-term elastic deformation over the arc. Here we study the long-term deformation field by carefully removing the short-term signals inferred from a-priori Plate convergence vectors and coupling strengths predicted by a thermal model. The obtained field shows that the change in velocities occurs along the longitude 135° ∼ 137°, and there exist a relatively rigid block and zones accommodating strains. Characteristic compressional deformation is found Northwest of Izu due possibly to the collision of the Izu-Bonin arc with Honshu. Plate convergence rate along the Nankai-Suruga Trough is considerably smaller in eastern parts, due partly to the transition from the Amurian to the North American Plate of the landward side, and partly to the motion of the Izu MicroPlate relative to the Philippine Sea Plate. This accounts for longer recurrence intervals of interPlate earthquakes in the Suruga Trough where the Tokai earthquake is anticipated to occur.
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Plate convergence and long‐term crustal deformation in central Japan
Geophysical Research Letters, 2001Co-Authors: Kosuke Heki, Shinichi MiyazakiAbstract:Surveys by continuous Global Positioning System in and around Japan revealed that the Amurian Plate collides with the North American Plate in central Japan by ∼2 cm/yr. Long-term crustal deformation seems to be influenced mainly by this collision although subduction of oceanic Plates governs short-term elastic deformation over the arc. Here we study the long-term deformation field by carefully removing the short-term signals inferred from a-priori Plate convergence vectors and coupling strengths predicted by a thermal model. The obtained field shows that the change in velocities occurs along the longitude 135° ∼ 137°, and there exist a relatively rigid block and zones accommodating strains. Characteristic compressional deformation is found Northwest of Izu due possibly to the collision of the Izu-Bonin arc with Honshu. Plate convergence rate along the Nankai-Suruga Trough is considerably smaller in eastern parts, due partly to the transition from the Amurian to the North American Plate of the landward side, and partly to the motion of the Izu MicroPlate relative to the Philippine Sea Plate. This accounts for longer recurrence intervals of interPlate earthquakes in the Suruga Trough where the Tokai earthquake is anticipated to occur.