Paleobiodiversity and Tectono-Sedimentary Records in the Mediterranean Tethys and Related Eastern Areas pp 221-223 | Cite as
Foraminiferal and Geochemical Input to OAE 2 Event at Jebel Bou Arif (Aures, Eastern Algeria)
Abstract
To highlight the anoxic event (OAE2) in the Aurès, a multidisciplinary study was conducted on the northern slope of Djebel Bou Arif (Aurès) where the sedimentation is marked by (1) marl-limestone deposits rich in bivalves and echinids and by foraminiferal limestones of the lower Turonian represented by Whiteinella archeocretacea [1], Helvetoglobotruncana Helvetica [2], Heterohelix sp. Microfacial analysis coupled with foraminiferal counting results, for quantitative and qualitative analyzes to calculate bioeonotic indices, demonstrated periods of basin instability. Two peaks of faunal renewal were observed. The first occurred at the Cenomanian-Turonian passage. It coincides with the anoxic event OAE2 and the second during the Middle Turonian. The interpretation of the geochemical results (CaCO3, TOC: Total Organic Carbone, δ13C and δ18O) indicates the presence of an important anoxic phase that starts in the Whiteinella archeocretacea zone and increases at the base of the Helvetoglobotruncana helvetica zone. The presence of organic matter associated with the evolutionary response of benthic foraminifera preceding the δ13C isotopic signal explains a well-marked transgressive regime.
Keywords
Cenomanian Turonian Aures OAE2 Foraminifera GeochemistryReferences
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