The Ordovician Period

This chapter provides general geologic information about the Ordovician Period, including definitions, classifications, fauna and flora, palaeogeography, and tectonic events that occurred during this period. The Karkur Talh, Naqus, and Gabgaba formations are three exposed Ordovician rock units in Egypt. In the subsurface, no Ordovician rock units have been discovered. Each of the rock mentioned above units was discussed in terms of definitions, stratigraphic boundaries, lithological components, distribution and thicknesses, and aga assignment. These rock units could be matched with their counterparts in neighbouring countries such as Libya, Jordan, Saudi Arabia, and Iraq. Based on facies types, faunal and floral associations, and trace fossils, the depositional environments of Ordovician rock units have been identified. A palaeogeographic facies map is created, allowing several synchronous environments to be identified, including cratonic and upland areas, coastal and marginal marine, shoal environments, and continental glacial sediments.