Upper miocene deposits from elmalabiad (tebessa northeastern of algeria ) : sedimentology, micropaliotology and paleoenviremantal implications

Abstract

The Miocene basin of Tebessa in northern Algeria is known for its low paleontological content. The analysis performed on trend samples at El HajraSafra gave new sedimentological, ichnoological and micropaleontological data. A fine fraction predominates in the sediment, followed by a sandy fraction, followed by a silty fraction with moderate CaCO3 content from the limestone reliefs (Maastricht limestone). Morphological analysis allows to predict more or less important evolutions (long transport) with blunt or less blunt particles. The mineral matrix corresponds to the clay minerals smectite, kaolinite,illite and sepiolite.The ichnological examination of the Ain Sidi Salah section revealed assemblages of eight ichnotaxons:Archaeonassaisp, Arenicolitesisp, Diplocterionisp, Helminthopsisisp,Palaeophycustubulis,Skolithos cf. S. Linearis, Taenidiumisp. These fossil prints were found in Skolithos and Cruziana,indicating a shallow marine environment (oxygen-rich littoral).Micropaleontological studies revealed microfaunal assemblages of 20 species in 10 genera, 13families. covering 10 species of ostracods were identified. Quantitative and qualitative analyses of benthic foraminifera indicate that the Trotonian deposits are located in shallow marine environments (littoral) and rich in oxygen.