Stratigraphic And Structural Controls On The Distribution Of Silurian Source Rocks In Northern Gondwana: Results Of A Field Based Study In Southern Libya

Rhuddanian transgressive black shales deposited across northern Gondwana include world class hydrocarbon source intervals in North Africa, Arabia and southern Turkey. The highest TOC values are usually concentrated in one (or more) layers in the lower part of the Silurian succession. These source units are commonly referred to as hot shales because high TOC values are often coincident with elevated uranium contents. Hot shales were deposited during the early stages of the Silurian marine transgression and their distribution was controlled by relief on the underlying depositional surface (Lüning et al., 2003). Understanding how glacial and tectonic processes influenced topography on the pre-Silurian depositional surface and how such topography influenced the deposition of hot shales can therefore reduce risk during hydrocarbon exploration.