气候变化领域集成服务门户(CCPortal): Microbially induced dolomite precipitates in Eocene lacustrine siliciclastic sequences in the Dongying depression; Bohai Bay Basin; China: Evidence from petrology; geochemistry; and numerical modeling

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DOI	10.1306/10191918225
	Microbially induced dolomite precipitates in Eocene lacustrine siliciclastic sequences in the Dongying depression; Bohai Bay Basin; China: Evidence from petrology; geochemistry; and numerical modeling
	Ma B.; Cao Y.; Eriksson K.A.
发表日期	2020
ISSN	0149-1423
起始页码	2051
结束页码	2075
卷号	104 期号:10
英文摘要	This study investigates the origin of dolomite by examining thick lacustrine sequences of evaporites, mudstones, and deep-water sublacustrine fan sandstones in the lower unit of the fourth member of the Eocene Shahejie Formation (Es4x) in Bohai Bay Basin, China. This petrographic, geochemical, and numerical modeling study recognizes evidence for microbially mediated dolomite precipitates in the Es4x sandstones, including the following: (1) spherical or elliptical dolomite aggregates consisting of submicrometer-sized crystals; (2) negative d13CVPDB (VPDB refers to Vienna Peedee belemnite) values of the dolomite cements (-6.56% to -3.35%); (3) relatively low precipitation temperatures of dolomite cements (39°C-65°C [102°F-149°F]) based on d18OVPDB values from -8.76% to -4.65%; and (4) negative 34SVCDT (VCDT refers to Vienna Canon Diablo troilite) values of associated framboidal pyrite (-3.9 to +5.7%) with respect to an anhydrite precursor (+21.2% to +37.8%). One-dimensional reactive transport modeling incorporating biodegradation kinetics was conducted to evaluate the link between biodegradation of organic matter and geochemical reactions of inorganic minerals during microbial sulfate reduction (MSR). Microbial metabolism in the model creates favorable geochemical conditions for dolomite precipitation by increasing pH, carbonate alkalinity, and Mg2+/Ca2+ ratio. The modeling results reproduce petrographic observations associated with the MSR process and indicate that the kinetics of microbial growth can significantly modify the geochemistry of simulated waters and enhance microbially mediated dolomite precipitation. Therefore, this study illustrates the effect of MSR in dolomite precipitation in a semiclosed and reducing continental lacustrine basin. Copyright © 2020. The American Association of Petroleum Geologists. All rights reserved.
英文关键词	Alkalinity; Biodegradation; Cements; Growth kinetics; Metabolism; Numerical models; Organic minerals; Pyrites; Sandstone; Sulfate minerals; Biodegradation kinetics; Carbonate alkalinity; Geochemical conditions; Geochemical reaction; Lacustrine sequence; Microbial metabolism; Precipitation temperature; Reactive transport modeling; Geochemistry; biodegradation; carbonate; dolomite; Eocene; geochemistry; numerical model; organic matter; petrology; precipitation (chemistry); pyrite; reactive transport; reduction; sandstone; sediment chemistry; siliciclastic deposit; Bohaiwan Basin; China; Dongying; Shandong; Belemnoidea
语种	英语
来源期刊	AAPG Bulletin
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/168688
作者单位	Key Laboratory of Tectonics and Petroleum Resources, China University of Geosciences, Ministry of Education, Wuhan, China; School of Geosciences, China University of Petroleum, Qingdao, China; Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
推荐引用方式 GB/T 7714	Ma B.,Cao Y.,Eriksson K.A.. Microbially induced dolomite precipitates in Eocene lacustrine siliciclastic sequences in the Dongying depression; Bohai Bay Basin; China: Evidence from petrology; geochemistry; and numerical modeling[J],2020,104(10).
APA	Ma B.,Cao Y.,&Eriksson K.A..(2020).Microbially induced dolomite precipitates in Eocene lacustrine siliciclastic sequences in the Dongying depression; Bohai Bay Basin; China: Evidence from petrology; geochemistry; and numerical modeling.AAPG Bulletin,104(10).
MLA	Ma B.,et al."Microbially induced dolomite precipitates in Eocene lacustrine siliciclastic sequences in the Dongying depression; Bohai Bay Basin; China: Evidence from petrology; geochemistry; and numerical modeling".AAPG Bulletin 104.10(2020).