Discussion on the Relationship between Graptolite Abundance and Organic Enrichment in Shales from the Wufeng and Longmaxi Formation, South China
doi: 10.14027/j.cnki.cjxb.2016.06.001
- Received Date: 2016-05-20
- Rev Recd Date: 2016-08-22
- Publish Date: 2016-12-10
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Key words:
- graptolite /
- shale gas /
- Wufeng Formation /
- Longmaxi Formation /
- organic enrichment /
- Wuxi area
Abstract: The graptolitic shales of the Wufeng and Longmaxi Formations were widely deposited across the Ordovician and Silurian transition in South China. Based on the statistics of graptolite abundance from nearly 400 shale samples and total organic content (TOC) from nearly 100 shale samples in the Ordovician-Silurian boundary succession in Wuxi area of Chongqing, 23 shale samples have been further selected to determine the contribution of the graptolite abundance to overall TOC. The energy spectrum analysis showed the C and O contents in the graptolites are higher than those in the host of Wufeng and Longmaxi shales, and the TOC of the graptolite is apparently higher than that of the surrounding host, showing the graptolite might be one of the contributors of organic matter in the shale. However, the overall TOC in shales generally has a poor correlation with the graptolite abundance in shales, implying that the graptolite abundance in shales has not a great impact on the organic enrichment.
Citation: | QIU Zhen, DONG DaZhong, LU Bin, ZHOU Jie, SHI ZhenSheng, WANG HongYan, LIN Wen, ZHANG ChenChen, LIU DeXun. Discussion on the Relationship between Graptolite Abundance and Organic Enrichment in Shales from the Wufeng and Longmaxi Formation, South China[J]. Acta Sedimentologica Sinica, 2016, 34(6): 1011-1020. doi: 10.14027/j.cnki.cjxb.2016.06.001 |