Essai de synthese stratigraphique du Paleozoique inferieur de la bordure septentrionale de la syneclise de Taoudeni (Sahara occidental)

Abstract

A tillite bed divides the lower Paleozoic of the northern border of the Taoudeni syncline into two unconformable series--the lower, or Infracambrian series and the upper, or Cambrian series. Recent studies involving the Infracambrian resulted in the recognition of three subdivisions. The lower, Char group, rests unconformably on the Precambrian basement. The middle, Atar group, is transgressive on the Char and is characterized by the development of carbonate intervals which contain stromatolites. The upper, Assabet el Hassian group, is transgressive on the Atar and contains fine sandstones, pelites, and argillites. These groups are recognizable from Atar (Mauritania) to the Algerian frontier.