Author(s)

Zhonghong Chen^1,2*, Qing Liu³, Shouchun Zhang³, Chunxue Jiang²

¹State Key Laboratory of Petroleum Resources and Prospecting, Faculty of Natural Resources and Information Technology, China University of Petroleum, Beijing, China.
²School of Geoscience, China University of Petroleum, Qingdao, China.
³Geological Scientific Research Institute, Shengli Oilfield Company, SINOPEC, Dongying, China.

The organic matter distribution and hydrocarbon generation potential as well as element distribution in the lacustrine mudstones of lower Member 3 of Paleogene Shahejie Formation in the Dongying depression, eastern China were investigated using methods of Rock-Eval pyrolysis, inductively coupled plasma emission spectrometer. The results show that most of the samples are high-quality source rocks with high TOC and S₂, and the oil shale samples are excellent source rocks with the TOC and S₂ greater than 5.0% and 20.0 mg/g, respectively. A freshwater depositional environment in the deep lake for the mudstones was indicated by lower values of biomarker ratios gammacerane/C₃₀ Hopane and C₃₅Hopane/C₃₄ Hopane. With the lacustrine regression, the ratios Ca/U, Ca/Ba, Ca/Mg, Ca/B, Ca/Li, Ca/Sr and Sr/Ba decrease, while Fe/(Ca + Mg) increases. In the section 3330 - 3370 m with enrichment of oil shale, the organic matter and inorganic elements present strong fluctuation. The quantitative relations among U, U/Th and TOC, S₂, %Ca are divided into two parts at boundary values of 7.0%, 32 mg/g and 11% for TOC, S₂ and %Ca, respectively.

Organic Matter, Mudstone and Shale, Element, Uranium, Lacustrine Basin

Chen, Z. , Liu, Q. , Zhang, S. and Jiang, C. (2015) Organic Matter and Elemental Composition of Mudstones in the Member 3 of Paleogene Shahejie Formation in the Dongying Depression, Eastern China. International Journal of Geosciences, 6, 537-548. doi: 10.4236/ijg.2015.66042.