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Exhumation during oblique transpression: The Feiran–Solaf region, Egypt
Author(s) -
ABUALAM T. S.,
STÜWE K.
Publication year - 2009
Publication title -
journal of metamorphic geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.639
H-Index - 114
eISSN - 1525-1314
pISSN - 0263-4929
DOI - 10.1111/j.1525-1314.2009.00827.x
Subject(s) - geology , metamorphic rock , metamorphism , metamorphic core complex , tectonics , geochemistry , compression (physics) , transpression , basement , tectonic phase , dome (geology) , petrology , shield , deformation (meteorology) , seismology , geomorphology , extensional definition , sinistral and dextral , oceanography , materials science , civil engineering , engineering , composite material
The Feiran–Solaf metamorphic complex of Sinai, Egypt, is one of the highest grade metamorphic complexes of a series of basement domes that crop out throughout the Arabian‐Nubian Shield. In the Eastern Desert of Egypt these basement domes have been interpreted as metamorphic core complexes exhumed in extensional settings. For the Feiran–Solaf complex an interpretation of the exhumation mechanism is difficult to obtain with structural arguments as all of its margins are obliterated by post‐tectonic granites. Here, metamorphic methods are used to investigate its tectonic history and show that the complex was characterized by a single metamorphic cycle experiencing peak metamorphism at ∼700–750 °C and 7–8 kbar and subsequent isothermal decompression to ∼4–5 kbar, followed by near isobaric cooling to 450 °C. Correlation of this metamorphic evolution with the deformation history shows that peak metamorphism occurred prior to the compressive deformation phase D 2 , while the compressive D 2 and D 3 deformation occurred during the near isothermal decompression phase of the P–T loop. We interpret the concurrence of decompression of the P–T path and compression by structural shortening as evidence for the Najd fault system exhuming the complex in an oblique transpressive regime. However, final exhumation from ∼15 km depth must have occurred due to an unrelated mechanism.