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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 3. (March)

First Page: 516

Last Page: 516

Title: Marine Permian Rocks of Tunisia: ABSTRACT

Author(s): J. Keith Rigby, Norman D. Newell, Donald W. Boyd

Article Type: Meeting abstract


The only marine Permian rocks in northern Africa are exposed in the Djebel Tebaga area of southern Tunisia. Fault-duplicated sections of approximately 850 m of marine shale, limestone, and dolomite, are exposed over a distance of approximately 15 km, in the mountains 25 km northwest of Medenine.

The sections grade upward from moderately deep marine shale and carbonate rocks, through a dolomitic, shallow marine section, to interbedded red and green terrigenous clastic and minor carbonate beds deposited in a littoral environment. The upper section is red beds, at and above the Permian-Triassic boundary. The apparently conformable sequence of Permian and Triassic rocks document a quiet termination of Tethyan marine deposition and suggest that the northern margin of the African plate was not involved in significant forward motion.

Marine Permian rocks near Medenine represent reef complexes that accumulated in relatively low-energy environments, interrupted only by short high-energy pulses of deposition. Reef talus is rare. The reefs are composed principally of algae with some sponges and limited bryozoans and brachiopods. Sponges are particularly abundant around the shaly margins of the carbonate masses. Echinoderms, gastropods, brachiopods, and bivalves are relatively minor interbioherm elements and are scattered through the abundant sponges. Fusulinaceans of the Neoschwagerina-Yabeina assemblage occur throughout the marine part of the sequence. Post-Jurassic faulting and possible intra-Permian folding interrupt the section.

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Copyright 1997 American Association of Petroleum Geologists