| Autor: |
Jacques Kornprobst, Ali Saquaque, Kevin Hefferan, Hassan Admou, Marcel Bohn, Jeffrey A. Karson, Rabia Hilal, Thierry Juteau, Scott D. Samson |
| Rok vydání: |
2002 |
| Předmět: |
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| Zdroj: |
Precambrian Research. 118:179-194 |
| ISSN: |
0301-9268 |
| DOI: |
10.1016/s0301-9268(02)00109-2 |
| Popis: |
Blueschists from the Bou Azzer inlier provide compelling evidence for Late Proterozoic subduction in the Anti-Atlas Mountains of Morocco. High-pressure/low-temperature metabasites containing blue amphibole minerals crossite and magnesioriebeckite record pressures in excess of 5 kbar. Together with regional relationships, the geologic setting of the blueschists constrains the polarity of Pan African subduction in this region, which occurred from ∼750 to 600 Ma. Blueschist facies rocks crop out in a heterogeneous assemblage of variably deformed and metamorphosed tectonic slices of ophiolitic fragments enclosed in a schistose serpentinite matrix. The melange belt containing the blueschist facies rocks is intruded by a number of diorite plutons, one of which has yielded a U/Pb radiometric age of 650 Ma. Together with Transaharan Belt to the southeast, the Anti-Atlas suture zone exposed within the Bou Azzer inlier contains among the oldest known blueschist-bearing, ophiolitic melanges in the world. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect