TY - JOUR AU - Edy Sutriyono, AU - Endang Wiwik Dyah Hastuti, AU - Budhi Kuswan Susilo, PY - 2021/11/23 Y2 - 2024/03/29 TI - GEOCHEMICAL ASSESSMENT OF LATE PALEOGENE SYNRIFT SOURCE ROCKS IN THE SOUTH SUMATRA BASIN JF - GEOMATE Journal JA - INTERNATIONAL JOURNAL OF GEOMATE VL - 11 IS - 23 SE - Articles DO - UR - https://geomatejournal.com/geomate/article/view/2535 SP - 2208-2215 AB - <p>The potential of Late Paleogene synrift source rocks in generating hydrocarbons within the South <br>Sumatra basin has been evaluated using geochemical and pyrolytic techniques. The samples were collected from <br>the outcropping shales of different layers constituting the Upper Oligocene Talang Akar Formation. Results of <br>TOC analysis reveal minor quantities of organic carbons, indicating poor to fair potential source rocks. The S2/S3<br>ratios indicate two apparent kerogen types. The majority of the samples is type III kerogen; however, there <br>appears minor type IV kerogen, implying the oxydized organic matter and no expulsion. The S1+S2 measurement<br>of all the pyrolysed rocks, except one sample LP 12A, yields less than 1 mg HC/g rock, supporting the proposed <br>scenario of little potential to generate hydrocarbons. Evaluation of hydrogen and oxygen indices confirms a gas <br>prone source, but all the shales analyzed, disregarding one sample LP 18, provide a direct evidence that the rock <br>section is immature to early mature to expel oil. Important notes can be made that the early stage of organic<br>maturation might have occurred due to heating, as a result of deeper burial during Miocene time prior to the <br>subsequent uplift in response to the Plio-Pleistocene orogeny.</p> ER -