Source Rock Characteristics, Organic Maturity, and Hydrocarbon Potential of the Lower Paleozoic Sequences in the Taurus Belt of Turkey

Like elsewhere in the world, Lower Paleozoic (Cambrian-Ordovician-Silurian) formations in Turkey are also exposed in limited areas. Lower Paleozoic sequences are exposed at various parts of the Taurus belt in southern Turkey. In this study, organic matter content, type, and maturity of organic matter and their hydrocarbon potential were investigated. In addition, the Lower Paleozoic is very restricted with respect to species and their diversity. Therefore, it is very important to investigate type and content of organic matter within the Lower Paleozoic sediments. In general, total organic carbon (TOC) values of Lower Paleozoic sequences are extremely low. TOC could not be measured in Cambrian, Ovack, and Caltepe limestones. Shales in the Emirgazi region have very low TOC values. Ordovician and Silurian units also have low TOC values. Total organic carbon in these sequences is residual carbon. In the S2-TOK kerogen diagram, all organic materials are plotted in the Type III kerogen field. All samples were composed dominantly of residual organic matter and lesser amounts of Type III kerogen. According to Tmax values, the Cambrian, Ordovician, and Silurian formations are over maturity character. In addition, these sequences have very low S1, S2, and HI values.