ABSTRACT
Publications on the Silurian strata of Arabia and own fieldwork in the eastern Ennedi Mountains and other parts of NW and NE Sudan led to a better understanding of the structural, paleogeographical and paleoclimatological situation in Silurian times. If the well documented situation in the Murzuk and Ghadames basins is typical for the NE African part of Gondwana, than the Lower Silurian sea transgressed rapidly far south and the subsequent northward regression was very slow. In NE Sudan, species of the rugosa group like Cruziana furcifera, C. goldfussi and C. rouaulti are typical for the Early Ordovician strata underlying the Early Silurian. The Early Silurian strata are characterized by Cruziana acacensis. The paleogeographic situation in Eastern Libya, Egypt, Northern Chad and Northern Sudan is more difficult to reconstruct, because subsidence was less intense and outcropping sediments are dominated by nearshore and fluvial deposits lacking index fossils.
