Origin of the abnormal carbon isotopic in organic matter of the Wenchang Formation, Zhu H sub-basin, Pearl River Mouth basin

被引：0
|
作者：
He Z. [1 ,2 ,3 ]
Yin X. [1 ,2 ,3 ]
Chen S. [1 ,2 ,3 ]
Lei M. [4 ]
Zhu B. [1 ,2 ,3 ]
Liu Y. [1 ,2 ,3 ]
Zhao R. [1 ,2 ,3 ]
Liu Y. [1 ,2 ,3 ]
机构：
[1] State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Sichuan, Chengdu
[2] Natural Gas Geology Key Laboratory of Sichuan Province, South-west Petroleum University, Sichuan, Chengdu
[3] School of Geoscience and Technology, South-west Petroleum University, Sichuan, Chengdu
[4] Hainan Branch of China National Offshore Oil Corporation Ltd, Hainan, Haikou
来源：
Dizhi Xuebao/Acta Geologica Sinica | 2024年 / 98卷 / 01期
关键词：
carbon isotope; paleoenvironment; Pear River Mouth basin; pediastrum; sapropelic organic matter; Zhu HI sub-basin;
D O I：
10.19762/j.cnki.dizhixuebao.2023038
中图分类号：
学科分类号：
摘要：
The phenomenon of sapropelic organic matter with high carbon isotope values, coupled with an abnormally high abundance of total organic carbon and hydrocarbon potential, has been identified in certain offshore lacustrine basins in China and rifting basins in the Atlantic. In this paper, we aim to investigate the mechanism behind the positive deviation of carbon isotope values within the organic matter of the Paleogene Wenchang Formation. Our research approach involves analyzing the organic carbon content, pollen, major and trace elements, as well as the carbon isotope and gas chromatograph-mass spectroscopy (GC-MS) of saturated hydrocarbon in both source rocks and crude oils. We also consider the characteristics of pediastrum in modern lakes to gain insights into the sources of organic matter, ancient environmental conditions, and the preservation and transformation of organic matter. The carbon isotope anomaly observed in the Wenchang Formation appears to be closely linked to various ancient environmental factors, including paleoclimate, paleoproductivity, and flourishing algae in the Zhu HI sub-basin. However, paleobathymetry may be a non-negligible significant factor on the scale of the third-order sequence. The Rb/K ratio, indicating the water depth, exhibits an increasing trend with depth, which coincides with the variations observed in carbon isotope values and TOC content. Additionally, modern lake investigations confirm the distribution of pediastrum across different water depths. Therefore, the bloom of "deep water type of pediastrum" is considered a key factor contributing to the high carbon isotope values observed in source rocks within the 2° Member of the Wenchang Formation in the Zhu HI sub-basin. © 2024 Geological Society of China. All rights reserved.
引用
收藏
页码：266 / 279
页数：13
相关论文
共 45 条
  • [1] Shunliang Bai, 19 98. Chemical-biostratigraphic study of on the Devonian Flemish-Famanian Event, Acta Scientiarum Naturalium Universitatis Pekinensis, 3 4, 2 - 3, pp. 363-368
  • [2] Boudreau R E A, Galloway J M, Michel F A., A paleolimnological record of Holocene climate and e n v i r o n m e n t a l change in t h e T e m a g a m i r e g i o n, n o r t h e a s t e r n O n t a r i o, P a l e o l i m n o l, 3, 3, pp. 445-461, (2005)
  • [3] Xuemei Chen, Xiaozhong Huang, Lingyu Tang, Fahu Chen, A preliminary investigation of relationship between modern Pediastrum and the level of Xingyun Lake, central Yunnan, and its implications for the interpretation of the fossil record discussion on the relationship between Modern Astellates and lake depth and fossil records in Xingyun Lake, Yunnan, Chinese Science Bulletin, 61, pp. 2395-2408, (2016)
  • [4] Dean W E, Gardner J V, Piper D Z., Inorganic geochemical indicators of glacial-interglacial changes in productivity and anoxia on the California continental margin, Geochimca et Cosmochimca Acta, 61, pp. 4507-4518, (1997)
  • [5] Yunxian Dong, Zhiwei Tan, Xiang Zhu, Yanying Guo, Yu Quan, Annual variation of the community structure and quantity of algae in Chenghai Lake annual changes in population structure and quantity of marine algae, Ecology and Environmental Sciences, 2 1, 7, pp. 1289-1295, (2012)
  • [6] Fedo C M, Nesbitt H W, Young G M., Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for paleoweathering conditions and provenance, Geology, 23, pp. 921-SQUOTE924, (1995)
  • [7] Ning Fu, Youchuan Li, Jianxin Sun, Yumei Sun, Jianyong Xu, Recognition of oil source and source rocks in Zhu El depression, Geoscience, 2 5, 6, pp. 1121-1130, (2011)
  • [8] Goncalves E T T, Bedregal R P, Coutinho L F., Petroleum system of the Camamu -A lmadabasin: A quantitative modeling approach, AAPG Memoir, 73, pp. 257-271, (2000)
  • [9] Harris N B, Freeman K H, Pancost R D, White T S, Mitchell G D., The character and origin of lacus trine source rocks in the Lower Cretaceous synrift section, Congo basin, West Africa, AAPG Bulletin, 88, 8, pp. 1163-1184, (2004)
  • [10] Baojia Huang, Xianming Xiao, Mingqiang Zhang, Geochemistry, grouping and origins of crude oils in the eastern Pearl River Mouth basin, offshore South China Sea, Organic Geochemistry, 34, pp. 993-1008, (2003)
12345