Simultaneous extensional exhumation across the Alboran Basin; implications for the causes of late orogenic extension

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doi: 10.1130/0091-7613(2003)031<0251:SEEATA>2.0.CO;2
Author(s): Platt, J. P.; Whitehouse, M. J.; Kelley, S. P.; Carter, A.; Hollick, L.
Author Affiliation(s): Primary:
University College London-Birkbeck, Research School of Earth Sciences, London, United Kingdom
Other:
Swedish Museum of Natural History, Sweden
Open University, United Kingdom
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 31(3), p.251-254. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. With GSA Data Repository Item 2003024. 32 refs.; illus., incl. sketch map
Summary: Large-scale crustal thinning of the Alpine orogen in the westernmost Mediterranean (Alboran Sea and surrounding regions) was rapid, simultaneous over an area of 60,000 km2, and took place ∼25 m.y. after the main crustal thickening event. Crustal thinning, which locally exposed subcontinental mantle, was accompanied by high-grade metamorphism and partial melting. Both U-Pb dating of zircon and thermal modeling of cooling histories indicate that the thermal peak was reached between 23 and 21 Ma over the entire region. Final exhumation and cooling followed immediately. Possible explanations for this dramatic late orogenic extension include subduction rollback, slab detachment, lithospheric delamination, and convective removal of subcontinental lithosphere. Of these processes, only convective removal of subcontinental lithosphere predicts a significant time lapse between crustal thickening and the onset of extension, the simultaneity of extension over the whole region, and heating of rock during rapid exhumation to produce the high-grade metamorphic event.
Year of Publication: 2003
Research Program: ODP Ocean Drilling Program
Key Words: 03 Geochronology; 16 Structural Geology; Absolute age; Africa; Alboran Sea; Andalusia Spain; Beni Bouchera Massif; Betic Cordillera; Cathodoluminescence; Cenozoic; Continental lithosphere; Convection; Cooling; Crustal thinning; Dates; Decompression; Europe; Exhumation; Experimental studies; Extension; High-grade metamorphism; Iberian Peninsula; Leg 161; Lithosphere; Mediterranean Sea; Mediterranean region; Metamorphic rocks; Metamorphism; Miocene; Morocco; Neogene; Nesosilicates; North Africa; ODP Site 976; Ocean Drilling Program; Orogeny; Orthosilicates; P-T conditions; Partial melting; Rif; Serrania de Ronda; Silicates; Southern Europe; Spain; Tertiary; U/Pb; U/Th/Pb; West Mediterranean; Zircon; Zircon group
Coordinates: N361219 N361219 W0041845 W0041845
Record ID: 2003025981
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States