Etude Biostratigraphique (foraminifères) et paléoécologique de la coupe de Slamna dans la région de Saida (Algérie Nord-Occidentale).

Abstract

This Work is based on the micropaleontological and biostratigraphic study of foraminifera in the claysandstone levels of the formation of the Callovian Age Saida Clays in the region of slamna the Mount of Saida. On the lithostratigraphic level, the series is represented by a clay-sandstone alternation admitting high carbonate levels of Callovian age which is rich in foraminifera. The taxonomic study of 17 samples shows a microfauna of foraminifera, very diverse, which contains 34 species belonging to 18 genera, some of which have a biostratigraphic interest. Biostratigraphically, the vertical distribution of the foraminifera has made it possible to highlight three (03) different microfaunic assemblages, which are succeeded from lower Callovian to Upper Callovian. From paleoecological point of view, paleo-environmental interpretations are based on microfauna data of foraminifera and and calcimetric analysis of clays to follow the variations in CaCo3 content. The results show an evolution from a deep to a shallow environment.