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Stratigraphy of the Mesozoic rocks above the Semail Ophiolite, Oman

Published online by Cambridge University Press:  01 May 2009

N. H. Woodcock
Affiliation:
Department of Earth Sciences, Downing Street, Cambridge CB2 3EQ
A. H. F. Robertson
Affiliation:
Grant Institute of Geology, West Mains Road, Edinburgh EH9 3JW

Summary

A revised stratigraphy is presented for the rocks which lie between the Upper Cretaceous Semail ophiolite and its post-emplacement sediment cover of uppermost Cretaceous to Tertiary age. Above the pelagic sediments of the ophiolite (Suhaylah Formation, Cenomanian–Turonian) occur ophiolite-derived clastic sediments (Zabyat Formation, ?Turonian–?Campanian) related to early stages of ophiolite emplacement. These formations are structurally overlain by the Batinah Complex, comprising Triassic to Cretaceous lithologies, all previously equated with the Hawasina rocks that now lie tectonically beneath the ophiolite. We recognize a lower melange unit to the complex, which demonstrably includes Hawasina lithologies. The melange formed by superficial rather than deep processes, but the mechanism by which Hawasina material was supplied to the ophiolite surface is unproven. The upper unit of the Batinah Complex shows a coherent stratigraphy which contrasts with that of the Hawasina. It comprises three main allochthonous tectonic sheets, within which we recognize three formations and one other informal unit. The upper Batinah Complex may have been tectonically derived not from the now subjacent Arabian margin but from another margin with a passive Mesozoic history.

Type
Articles
Copyright
Copyright © Cambridge University Press 1982

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