国家冰川冻土沙漠科学数据中心

元数据

名称	Early-stage marine dolomite altered by hydrothermal fluids in the Middle Permian Maokou Formation in the eastern Sichuan Basin, Southern China
科技资源标识	CSTR:11738.14.NCDC.XDA14.PP4322.2024
DOI	https://doi.org/10.1016/j.marpetgeo.2021.105367
数据共享方式	开放下载
摘要	Deciphering the dolomitization process is the key to understanding the formation of massive dolostones on shallow-marine platforms, it also improves our understanding of dolostone reservoirs. Hydrothermal fluids are suggested to be a potential mechanism for dolomitization; however, determining whether hydrothermal fluids are responsible for dolomitization or the recrystallization of an early dolostones is poorly understood. The dolomite of Maokou Formation (Guadalupain) in the eastern part of the Sichuan Basin is a good case study on the hydrothermal dolomitization and recrystallization. Based on petrographic observation, the massive dolostone (MD) consists of fine-crystalline dolomite (D1), fine to medium crystalline dolomite (D2) and coarse-crystalline dolomite (D3), and the patchy dolostone (PD) which is composed of medium to coarse dolomite with an euhedral to subhedral texture. Since the fine-crystalline dolomite is cross-cut by low amplitude stylolites, and is composed of euhedral dolomite with a dull red luminescence, dolomitization is interpreted to have occurred in near surface condition. While the Fe, Mn, and ΣREE concentrations, δ13CVPDB values, 87Sr/86Sr ratios, and REE Pattern of D1 are comparable to those of the coexisting limestone, and the δ18OVPDB values are slightly higher than that of the coeval limestone, indicating that the dolomitization fluid of D1 was derived from Middle Permian seawater. In contrast, zebra fabrics and saddle dolomites are common in D2 and D3, and their geochemical characteristics and cathluminescence are quite different from those of D1 but they are similar to those of the saddle dolomites. Besides, the fluid inclusions in D2 and D3 have high homogenization temperatures and salinities, which are also similar to those of the saddle dolomite. Moreover, the D2 shows an inequigranular texture, and there are no obvious boundaries between D1, D2 and D3. Therefore, the D2 and D3 were recrystallized upon D1 by hydrothermal fluids related to the Emeishan magmatism. The patchy dolostone exhibits a non-stoichiometric composition and low degree of cation ordering, suggests rapid and incomplete dolomitization. The dolomitization of PD is interpreted to be the replacement caused by hydrothermal fluids as the PD exhibits negative δ18OVPDB values, high homogenization temperatures and salinity, positive Eu anomalies and REE Patterns similar to those of the saddle dolomites. The porosity and stoichiometry of the D1 are higher and lower, respectively, than those of D2 and D3, and the vugs are almost entirely filled. Thus, the hydrothermal fluids were destructive for the formation of the dolostone reservoir of Maokou Formation in the study area.
学科分类	170.50
关键词	Dolomitization Marine dolomite Hydrothermal fluids Massive dolostone Patchy dolostone Maokou formation Sichuan basin
作者	Ting Li,Dancheng Zhu,Minglei Yang,Xihua Zhang,Pingping Li,Chaojin Lu,Huayao Zou
数据量	23.1 MiB
论文类型：	journal
论文网址：	https://www.sciencedirect.com/science/article/pii/S0264817221004700
期刊名称：	Marine and Petroleum Geology
出版时间：	2021-12-01

引用和标注

数据引用

Ting Li,Dancheng Zhu,Minglei Yang,Xihua Zhang,Pingping Li,Chaojin Lu,Huayao Zou. Early-stage marine dolomite altered by hydrothermal fluids in the Middle Permian Maokou Formation in the eastern Sichuan Basin, Southern China. 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://cstr.cn/CSTR:11738.14.NCDC.XDA14.PP4322.2024.

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本作品采用知识共享署名 4.0 国际许可协议进行许可。

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项目信息详情

项目名称：深层油气形成与分布预测
项目编号：XDA14010000
项目类别：中国科学院战略性先导科技专项（A类）