Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
Extensional dismemberment of the Betic Cordillera during Late Oligocene to Early Miocene time caused attenuation and excision of a crustal section overlying mantle peridotite. An integrated study of metapelites overlying the peridotite sheet in the Carratraca area shows truncation of a typical oroge...
| Formaat: | Journal article |
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| Gepubliceerd in: |
Geological Society of London
1999
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| Onderwerpen: |
| _version_ | 1826282818138800128 |
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| collection | OXFORD |
| description | Extensional dismemberment of the Betic Cordillera during Late Oligocene to Early Miocene time caused attenuation and excision of a crustal section overlying mantle peridotite. An integrated study of metapelites overlying the peridotite sheet in the Carratraca area shows truncation of a typical orogenic cycle of burial and heating by rapid exhumation and late- to post-tectonic, low-pressure metamorphism. Attenuation by a factor of five or more condensed a greenschist to granulite section to 4 km structural thickness. Initially coaxial attenuation of the sequence, involving formation of a flat-lying foliation and conjugate shear bands, was superseded by non-coaxial deformation concentrated along low-angle, top-to-the-NE, extensional fault zones. These excised parts of the metamorphic section; a 2 km loss was calculated across one fault zone. Thermobarometry throughout this section demonstrates that the structural attenuation was related to isothermal decompression to low pressures (2-4 kbar) even at the base of the crustal section. A late thermal event largely postdates the ductile stage of attenuation, particularly in the upper part of the section. Thermal modelling implies that this thermal event could not have been produced by the hot peridotite sheet alone. Rapid tectonic exhumation and asthenospheric upwelling are the probable causes, following detachment of material from the base of the lithosphere. |
| first_indexed | 2024-03-07T00:49:34Z |
| format | Journal article |
| id | oxford-uuid:85eaa507-44c7-46f3-aafc-7a73177d43a2 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T00:49:34Z |
| publishDate | 1999 |
| publisher | Geological Society of London |
| record_format | dspace |
| spelling | oxford-uuid:85eaa507-44c7-46f3-aafc-7a73177d43a22022-03-26T22:00:38ZAttenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:85eaa507-44c7-46f3-aafc-7a73177d43a2Earth sciencesEarth SciencesOxford University Research Archive - ValetGeological Society of London1999Extensional dismemberment of the Betic Cordillera during Late Oligocene to Early Miocene time caused attenuation and excision of a crustal section overlying mantle peridotite. An integrated study of metapelites overlying the peridotite sheet in the Carratraca area shows truncation of a typical orogenic cycle of burial and heating by rapid exhumation and late- to post-tectonic, low-pressure metamorphism. Attenuation by a factor of five or more condensed a greenschist to granulite section to 4 km structural thickness. Initially coaxial attenuation of the sequence, involving formation of a flat-lying foliation and conjugate shear bands, was superseded by non-coaxial deformation concentrated along low-angle, top-to-the-NE, extensional fault zones. These excised parts of the metamorphic section; a 2 km loss was calculated across one fault zone. Thermobarometry throughout this section demonstrates that the structural attenuation was related to isothermal decompression to low pressures (2-4 kbar) even at the base of the crustal section. A late thermal event largely postdates the ductile stage of attenuation, particularly in the upper part of the section. Thermal modelling implies that this thermal event could not have been produced by the hot peridotite sheet alone. Rapid tectonic exhumation and asthenospheric upwelling are the probable causes, following detachment of material from the base of the lithosphere. |
| spellingShingle | Earth sciences Earth Sciences Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain |
| title | Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
|
| title_full | Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
|
| title_fullStr | Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
|
| title_full_unstemmed | Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
|
| title_short | Attenuation and excision of a crustal section during extensional exhumation: the Carratraca Massif, Betic Cordillera, southern Spain
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| title_sort | attenuation and excision of a crustal section during extensional exhumation the carratraca massif betic cordillera southern spain |
| topic | Earth sciences Earth Sciences |