Antarctic/Scotia plate convergence off southernmost Chile
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| Format: | Artículo científico |
| Sprache: | en |
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Universitat de Barcelona
2007
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| _version_ | 1866814309533745152 |
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| author | A. Polonia |
| author_facet | A. Polonia |
| contents | Antarctic/Scotia plate convergence off southernmost Chile A. Polonia L. Torelli Ciencias de la Tierra Trench Marine geology Plate tectonics Continental margin Subduction complex The southern tip of South America off Chile has suffered a long phase of ocean-continent convergence which has shapedthe continental margin through different phases of accretion and tectonic erosion. The present accretionary wedge is a discontinuousgeological record of plate convergence and records only part of the accretionary processes resumed after Chileridge consumption (14 Ma). The structural style of the subduction complex, such as rates of sediment accretion and tectonicerosion, structural vergence, width of the accretionary wedge, taper angle and deformation in the forearc basin, variesalong the margin. Large taper values are related to narrow wedges and seaward vergent structures. Low tapers occur wheredeformation at the toe of the accretionary complex is spread over wide areas and is related both to landward and seawardvergent thrust faults. Seismic data interpretation contributes to define more accurately frontal wedge morphology andgeometry of subduction and suggests that different modes of accretion together with tectonic erosion may be active concurrentlyalong the trench at different locations. In areas of subduction driven accretionary processes the majority of trenchsediments are involved in accretionary processes and sediments are uplifted and piled up in the form of imbricate thrustsheets. In areas where the wedge is non-accretionary the continental margin shows steeper continental slopes associatedwith narrow accretionary wedges, more intense sediment disruption and very shallow décollement levels. Variation instructural style and in the geometry of the forearc region setting off Southernmost Chile, has been interpreted as related tothe existence of different structural domains: the nature of their boundaries is still unclear mainly for the lack of high resolutionbathymetric data. They have been tentatively related to tectonic lineaments belonging to the Magellan Fault systemand/or to the character and morphology of the converging plates (lateral heterogeneities, sea-mounts and fracture zones),which produce a segmentation of the margin 2007 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50550403 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.4 Vol.5 |
| format | Artículo científico |
| id | redalyc_50550403 |
| language | en |
| publishDate | 2007 |
| publisher | Universitat de Barcelona |
| spellingShingle | Antarctic/Scotia plate convergence off southernmost Chile A. Polonia Ciencias de la Tierra Trench Marine geology Plate tectonics Continental margin Subduction complex Antarctic/Scotia plate convergence off southernmost Chile A. Polonia L. Torelli Ciencias de la Tierra Trench Marine geology Plate tectonics Continental margin Subduction complex The southern tip of South America off Chile has suffered a long phase of ocean-continent convergence which has shapedthe continental margin through different phases of accretion and tectonic erosion. The present accretionary wedge is a discontinuousgeological record of plate convergence and records only part of the accretionary processes resumed after Chileridge consumption (14 Ma). The structural style of the subduction complex, such as rates of sediment accretion and tectonicerosion, structural vergence, width of the accretionary wedge, taper angle and deformation in the forearc basin, variesalong the margin. Large taper values are related to narrow wedges and seaward vergent structures. Low tapers occur wheredeformation at the toe of the accretionary complex is spread over wide areas and is related both to landward and seawardvergent thrust faults. Seismic data interpretation contributes to define more accurately frontal wedge morphology andgeometry of subduction and suggests that different modes of accretion together with tectonic erosion may be active concurrentlyalong the trench at different locations. In areas of subduction driven accretionary processes the majority of trenchsediments are involved in accretionary processes and sediments are uplifted and piled up in the form of imbricate thrustsheets. In areas where the wedge is non-accretionary the continental margin shows steeper continental slopes associatedwith narrow accretionary wedges, more intense sediment disruption and very shallow décollement levels. Variation instructural style and in the geometry of the forearc region setting off Southernmost Chile, has been interpreted as related tothe existence of different structural domains: the nature of their boundaries is still unclear mainly for the lack of high resolutionbathymetric data. They have been tentatively related to tectonic lineaments belonging to the Magellan Fault systemand/or to the character and morphology of the converging plates (lateral heterogeneities, sea-mounts and fracture zones),which produce a segmentation of the margin 2007 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50550403 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.4 Vol.5 |
| title | Antarctic/Scotia plate convergence off southernmost Chile |
| topic | Ciencias de la Tierra Trench Marine geology Plate tectonics Continental margin Subduction complex |
| url | https://www.redalyc.org/articulo.oa?id=50550403 |