Organic Matter and Elemental Composition of Mudstones in the Member 3 of Paleogene Shahejie Formation in the Dongying Depression, Eastern China
- 1 State Key Laboratory of Petroleum Resources and Prospecting, Faculty of Natural Resources and Information Technology, China University of Petroleum, Beijing, China
- 2 Geological Scientific Research Institute, Shengli Oilfield Company, SINOPEC, Dongying, China
- 3 Geological Scientific Research Institute, Shengli Oilfield Company, SINOPEC, Dongying, China
- 4 School of Geoscience, China University of Petroleum, Qingdao, China
Abstract
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 S 2 , and the oil shale samples are excellent source rocks with the TOC and S 2 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/C 30 Hopane and C 35 Hopane/C 34 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, S 2 , %Ca are divided into two parts at boundary values of 7.0%, 32 mg/g and 11% for TOC, S 2 and %Ca, respectively.
- Chen, Z.H. and Zha, M. (2006) Sedimentary Characteristics of Source Rocks in Fluctuation from Lake Facies: An Example from Dongying Depression, China. Journal of Lake Science, 18, 29-35.
- Chen, Z.H. and Zha, M. (2008) Mechanism of Overpressured Fluid Compartment and Its Controlling on Hydrocarbon Migration and Accumulation in Faulted Lacustrine Basin: A Case Study from the Dongying Sag, Bohai Bay Basin. Chinese Journal of Geology, 43, 50-64.
- Chen, Z.H., Zha, M. and Jin, Q. (2008) Mineral Element al Response to the Evolution of Terrestrial Brine Faulted-Basin: A Case Study in the Paleogene of Well Haoke-1, Dongying Sag. Acta Sedimentologica Sinica, 26, 924-932.
- Moon, H.S., Komlos, J. and Jaffe, P.R. (2007) Uranium Reoxidation in Previously Bioreduced Sediment by Dissolved Oxygen and Nitrate. Environmental Science & Technology, 41, 4587-4592. http://dx.doi.org/10.1021/es063063b
- Regenspurg, S., Margot-Roquier, C., Harfouche, M., Froidevaux, P., Steinmann, P., Junier, P. and Bernier-Latmani, R. (2010) Speciation of Naturally-Accumulated Uranium in an Organic-Rich Soil of an Alpine Region (Switzerland). Geochimicaet Cosmochimica Acta, 74, 2082-2098. http://dx.doi.org/10.1016/j.gca.2010.01.007
- Mehta, V.S., Maillot, F., Wang, Z.M., Catalano, J.G. and Giammar, D.E. (2014) Effect of Co-Solutes on the Products and Solubility of Uranium (VI) Precipitated with Phosphate. Chemical Geology, 364, 66-75. http://dx.doi.org/10.1016/j.chemgeo.2013.12.002
- Demaison, G.J. and Moore, G.T. (1980) Anoxic Environments and Oil Source Bed Genesis. Organic Geochemistry, 2, 9-31. http://dx.doi.org/10.1016/0146-6380(80)90017-0
- Talbot, M.R. and Johannessen, T. (1992) A High Resolution Palaeoclimatic Record for the Last 27,500 Years in Tropical West Africa from the Carbon and Nitrogen Isotopic Composition of Lacustrine Organic Matter, Earth Planet. Science Letters, 110, 23-37. http://dx.doi.org/10.1016/0012-821X(92)90036-U
- Lyons, R.P., Scholz, C.A., Buoniconti, M.R. and Martin, M.R. (2011) Late Quaternary Stratigraphic Analysis of the Lake Malawi Rift, East Africa: An integration of Drillcore and Seismic-Reflection Data. Palaeogeography, Palaeoclimatology, Palaeoecology, 303, 20-37. http://dx.doi.org/10.1016/j.palaeo.2009.04.014
- Sharp, J.O., Lezama-Pacheco, J.S., Schofield, E.J., Junier, P., Ulrich, K.-U., Chinni, S., Veeramani, H., Margot-Roquier, C., Webb, S.M., Tebo, B.M., Giammar, D.E., Bargar, J.R. and Bernier-Latmani, R. (2011) Uranium Speciation and Stability after Reductive Immobilization in Aquifer Sediments. Geochimica et Cosmochimica Acta, 75, 6497-6510. http://dx.doi.org/10.1016/j.gca.2011.08.022