Organic petrology and geochemistry source rock of shale Nanggulan formation, Watupuru river traverse, Banjararum, Kulon Progo, Yogyakarta

The interesting concern on the Watupuru River Traverse is the outcroping of Nanggulan Formation shale rock of Eocene Age. There are 2 outcrops of source rock which have different of organic composition and potential of hydrocarbons (HC) along of Watupuru traverse. Paleontological analysis results from measurements of 2 profiles of shale outcrops, the age of shale outcrops 1 and 2 along of track Watupuru River of Late Eocene – Middle Oligocene (P17 – P19) evidenced by the fossils of Globigerina ampliapertura, Globigerina praebulloides leroyi, and Pseudohastigerina micra including Nanggulan Formation. This is confirmed with Kulon Progo Regional Stratigraphy by Rahardjo, et al [5]. The methodology research are shale outcrops profile making (shale outcrops-1 and outcrop-2), organic petrological analysis is to determine the characteristics of the maceral constituents of shale. Meanwhile geochemical analysis is from Total Organic Carbon (TOC), vitrinite reflectance and pyrolysis rock-eval. Based on the results of organic petrology and organic geochemical analysis of 5 shale samples of Nanggulan Formation, which are found in two shale outcrops, where shale outcrop-1 the quality of organic material is moderate to very good organic, dominated by the vitrinite maceral group, kerogen type III (HC potential to gas prone), the origin from terrestrial environment, vitrinite reflectance (Ro=0.26-0.32% Vol.) is immature. While shale outcrop-2 the quality of organic material is very good - special, dominated by alginite maceral, kerogen type II (HC potential to oil prone) the origin from freshwater-saline water environment, vitrinite reflectance (Ro=0.25-026 % Vol.) is immature.