EVOLUTION OF JURASSIC CARBONATE PLATFORM (NE ALGERIAN)

Abstract

This study focuses on an area located at the convergence of the allochthonous and the Atlasic forelands of the Northren Algerian Alpine Belt. The objective of this work is to reconstruct the drowning history of the Jurassic carbonate platform, and discuss its relationship with the geodynamic evolution of the Southern Tethysian margin.

The identification and interpretation of drowning events in the platforms can help significantly to the reconstruction of the depositional, tectonics and eustatic history of these platforms.

The stratigraphic interpretation and correlation of the study area Jurassic series from a few cross-sections, have allowed the highlighting of the platform physiography during this geological period and individualizing three stratigraphic units.

The synthesis of bio-sedimentological data reveals diversified facies, involving various deposits environments ranging from supratidal to deep pelagic peleoenvironments. These facies have evolved within subsidante carbonate ramp. Thereof has experienced drowning (Toarcian) and filling (Tithonian, Berriasian) phases, in relation with the eustatic sea level changes at the global scale and regional tectonics.

Keywords: Jurassique; platform; facies; drawning.