Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps
In the Alps a major extensional shear zone unroofed eclogites in its footwall from 30 kbar to c. 10 kbar, implying of the order of 60 km of relative vertical movement in the period 45-36 Ma. The horizontal component of divergence was of the order of 100 km. We use the foreland basin sedimentary reco...
| Main Authors: | , , |
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| Format: | Journal Article |
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Geological Society of London
2001
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| Online Access: | http://www.lyellcollection.org/ http://hdl.handle.net/20.500.11937/11674 |
| _version_ | 1848747868715745280 |
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| author | Wheeler, J. Reddy, Steven Cliff, R. |
| author_facet | Wheeler, J. Reddy, Steven Cliff, R. |
| author_sort | Wheeler, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | In the Alps a major extensional shear zone unroofed eclogites in its footwall from 30 kbar to c. 10 kbar, implying of the order of 60 km of relative vertical movement in the period 45-36 Ma. The horizontal component of divergence was of the order of 100 km. We use the foreland basin sedimentary record to prove that the extension was contemporaneous with thrusting in units structurally beneath the eclogites (the Brianconnais and/or External Zones). This thrust-related convergence during that time period was of the order of 44-56 km and therefore of the same order of magnitude as internal zone divergence. Extension may have been driven by internal density contrasts. Buoyant continental crust underneath the mafic eclogites, or dense subducted slab offset from the orogen, can induce extension. Any dynamic model must account for the comparable magnitudes of extension and shortening in adjacent parts of the orogen: relative plate motions in the period 45-36 Ma played a subsidiary role. |
| first_indexed | 2025-11-14T06:55:59Z |
| format | Journal Article |
| id | curtin-20.500.11937-11674 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:55:59Z |
| publishDate | 2001 |
| publisher | Geological Society of London |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-116742017-02-27T15:15:16Z Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps Wheeler, J. Reddy, Steven Cliff, R. extension kinematics Alps foreland basins eclogite In the Alps a major extensional shear zone unroofed eclogites in its footwall from 30 kbar to c. 10 kbar, implying of the order of 60 km of relative vertical movement in the period 45-36 Ma. The horizontal component of divergence was of the order of 100 km. We use the foreland basin sedimentary record to prove that the extension was contemporaneous with thrusting in units structurally beneath the eclogites (the Brianconnais and/or External Zones). This thrust-related convergence during that time period was of the order of 44-56 km and therefore of the same order of magnitude as internal zone divergence. Extension may have been driven by internal density contrasts. Buoyant continental crust underneath the mafic eclogites, or dense subducted slab offset from the orogen, can induce extension. Any dynamic model must account for the comparable magnitudes of extension and shortening in adjacent parts of the orogen: relative plate motions in the period 45-36 Ma played a subsidiary role. 2001 Journal Article http://hdl.handle.net/20.500.11937/11674 http://www.lyellcollection.org/ Geological Society of London fulltext |
| spellingShingle | extension kinematics Alps foreland basins eclogite Wheeler, J. Reddy, Steven Cliff, R. Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title | Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title_full | Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title_fullStr | Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title_full_unstemmed | Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title_short | Kinematic linkage between internal zone extension and shortening in more external units in the NW Alps |
| title_sort | kinematic linkage between internal zone extension and shortening in more external units in the nw alps |
| topic | extension kinematics Alps foreland basins eclogite |
| url | http://www.lyellcollection.org/ http://hdl.handle.net/20.500.11937/11674 |