Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles
In the southeast corner of the Caribbean, westward subduction of (Atlantic) oceanic South America beneath the Lesser Antilles transitions to east‐west transform motion between continental South America and the Caribbean plate. This geometry requires negatively buoyant, subducting, oceanic South Amer...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2008-11-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2008GC002084 |
| _version_ | 1797257625964904448 |
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| author | S. A. Clark M. Sobiesiak C. A. Zelt M. B. Magnani M. S. Miller M. J. Bezada A. Levander |
| author_facet | S. A. Clark M. Sobiesiak C. A. Zelt M. B. Magnani M. S. Miller M. J. Bezada A. Levander |
| author_sort | S. A. Clark |
| collection | DOAJ |
| description | In the southeast corner of the Caribbean, westward subduction of (Atlantic) oceanic South America beneath the Lesser Antilles transitions to east‐west transform motion between continental South America and the Caribbean plate. This geometry requires negatively buoyant, subducting, oceanic South American lithosphere to progressively detach from positively buoyant, continental South American lithosphere. The most widely accepted model is slab break‐off, with oblique arc‐continent collision and northwest dipping, continental subduction precipitating narrow rifting in the subducting slab. In contrast, the subduction‐transform edge propagator (STEP) model conceptualizes progressive detachment along a vertical, dip‐slip tear through the lithosphere, with stress focused at the edge of the propagating transform boundary. We present four types of seismic data to resolve the ongoing lithospheric detachment: local seismicity, receiver functions, wide‐angle seismic velocity inversion, and a regional, balanced cross section constrained by petroleum industry data. These four data sets image a near‐vertical tear extending through the entire lithosphere, revealing a key mechanism for the structural evolution of Venezuela. |
| first_indexed | 2024-04-24T22:40:37Z |
| format | Article |
| id | doaj.art-8d930b81ba934b1b847e7a1dd68cb936 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-04-24T22:40:37Z |
| publishDate | 2008-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-8d930b81ba934b1b847e7a1dd68cb9362024-03-19T04:50:49ZengWileyGeochemistry, Geophysics, Geosystems1525-20272008-11-01911n/an/a10.1029/2008GC002084Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser AntillesS. A. Clark0M. Sobiesiak1C. A. Zelt2M. B. Magnani3M. S. Miller4M. J. Bezada5A. Levander6Department of Earth Science Rice University Houston Texas 77251 USAGeoForschungsZentrum Potsdam D‐14473 Potsdam GermanyDepartment of Earth Science Rice University Houston Texas 77251 USACenter for Earthquake Research and Information University of Memphis Memphis Tennessee 38152 USADepartment of Earth Science Rice University Houston Texas 77251 USADepartment of Earth Science Rice University Houston Texas 77251 USADepartment of Earth Science Rice University Houston Texas 77251 USAIn the southeast corner of the Caribbean, westward subduction of (Atlantic) oceanic South America beneath the Lesser Antilles transitions to east‐west transform motion between continental South America and the Caribbean plate. This geometry requires negatively buoyant, subducting, oceanic South American lithosphere to progressively detach from positively buoyant, continental South American lithosphere. The most widely accepted model is slab break‐off, with oblique arc‐continent collision and northwest dipping, continental subduction precipitating narrow rifting in the subducting slab. In contrast, the subduction‐transform edge propagator (STEP) model conceptualizes progressive detachment along a vertical, dip‐slip tear through the lithosphere, with stress focused at the edge of the propagating transform boundary. We present four types of seismic data to resolve the ongoing lithospheric detachment: local seismicity, receiver functions, wide‐angle seismic velocity inversion, and a regional, balanced cross section constrained by petroleum industry data. These four data sets image a near‐vertical tear extending through the entire lithosphere, revealing a key mechanism for the structural evolution of Venezuela.https://doi.org/10.1029/2008GC002084lithospheric detachmentmantle dynamicsSTEPjelly sandwichslab break‐offtear |
| spellingShingle | S. A. Clark M. Sobiesiak C. A. Zelt M. B. Magnani M. S. Miller M. J. Bezada A. Levander Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles Geochemistry, Geophysics, Geosystems lithospheric detachment mantle dynamics STEP jelly sandwich slab break‐off tear |
| title | Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles |
| title_full | Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles |
| title_fullStr | Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles |
| title_full_unstemmed | Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles |
| title_short | Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles |
| title_sort | identification and tectonic implications of a tear in the south american plate at the southern end of the lesser antilles |
| topic | lithospheric detachment mantle dynamics STEP jelly sandwich slab break‐off tear |
| url | https://doi.org/10.1029/2008GC002084 |
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