Early dolomitisation of the Lower-Middle Ordovician cyclic carbonates in northern Tarim Basin, NW China

doi:10.1007/s11430-017-9056-1

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院油气资源研究重点实验室

	Early dolomitisation of the Lower-Middle Ordovician cyclic carbonates in northern Tarim Basin, NW China
	Guo, Chuan 1; Chen, DaiZhao 1; Dong, ShaoFeng 1; Qian, YiXiong 2; Liu, CunGe 3
刊名	SCIENCE CHINA-EARTH SCIENCES
	2017-07-01
卷号	60 期号:7 页码:1283-1298
关键词	Early dolomitisation Cyclicity Carbonate Lower-Middle Ordovician Tarim Basin
ISSN号	1674-7313
DOI	10.1007/s11430-017-9056-1
文献子类	Article
英文摘要	High-frequency metre-scale cycles are present within the Lower-Middle Ordovician carbonate successions in northern Tarim Basin, NW China. These metre-scale cycles were variably dolomitised from top to bottom. Three types of replacive dolomites were recognised, including dololaminite (very finely to finely crystalline, planar-s to nonplanar-a dolomite; type-1), patterned dolomite (finely crystalline, planar-s dolomite; type-2), and mottled dolomite (finely to medium crystalline, nonplanar-a(s) dolomite; type-3). Petrographic evidence indicate these dolomites were primarily deposited in supratidal to restricted subtidal environments, and formed in near-surface to shallow burial realms. Geochemically, all types of dolomites have similar delta C-13 and Sr-87/Sr-86 ratios comparable to calcite precipitated in equilibrium with the Early-Middle Ordovician seawater. These geochemical attributes indicate that these dolomites were genetically associated and likely formed from connate seawater-derived brines. Of these, type-1 dolomite has delta O-18 values (aEuro'4.97aEuro degrees toaEuro'4.04aEuro degrees VPDB) slightly higher than those of normal seawater dolomite of the Early-Middle Ordovician age. Considering the absence of associated evaporites within type-1 dolomite, its parental fluids were likely represented by slightly evaporated (i.e., mesosaline to penesaline) seawater with salinity below that of gypsum precipitation. More depleted delta O-18 values (aEuro'7.74aEuro degrees toaEuro'5.20aEuro degrees VPDB) of type-2 dolomite and its stratigraphic position below type-1 dolomite indicate the generation of this dolomite from mesosaline to penesaline brines at higher temperatures in near-surface to shallow burial domains. Type-3 dolomite yields the most depleted delta O-18 values (-9.30aEuro degrees to-7.28aEuro degrees VPDB), pointing to that it was most likely formed from coeval seawater-derived brines at highest temperatures in a shallow burial setting. There is a downward decreasing trend in delta O-18 values from type-1 through type-2 to type-3 dolomites, and in abundance of dolomites, indicating that the dolomitising fluids probably migrated downward from above and persisted into shallow burial conditions.
WOS关键词	TRIASSIC PLATFORM CARBONATES ; SULFATE-REDUCING BACTERIA ; CANADA SEDIMENTARY BASIN ; UPPER-KNOX GROUP ; ISOTOPE GEOCHEMISTRY ; EARLY DOLOMITIZATION ; DOLOMITE FORMATION ; SOUTH CHINA ; EPIGENETIC DOLOMITIZATION ; HYDROTHERMAL ALTERATION
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000406020600006
资助机构	Petrochemical Joint Foundation of China(U1663209) ; National Natural Science Foundation of China(41502118) ; Petrochemical Joint Foundation of China(U1663209) ; National Natural Science Foundation of China(41502118) ; Petrochemical Joint Foundation of China(U1663209) ; National Natural Science Foundation of China(41502118) ; Petrochemical Joint Foundation of China(U1663209) ; National Natural Science Foundation of China(41502118)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/42776]
专题	地质与地球物理研究所_中国科学院油气资源研究重点实验室
通讯作者	Chen, DaiZhao
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, Beijing 100029, Peoples R China 2.SINOPEC, Wuxi Res Inst Petr Geol, Wuxi 214151, Peoples R China 3.Guangdong Univ Petrochem Technol, Coll Petr Engn, Maoming 525000, Peoples R China
推荐引用方式 GB/T 7714	Guo, Chuan,Chen, DaiZhao,Dong, ShaoFeng,et al. Early dolomitisation of the Lower-Middle Ordovician cyclic carbonates in northern Tarim Basin, NW China[J]. SCIENCE CHINA-EARTH SCIENCES,2017,60(7):1283-1298.
APA	Guo, Chuan,Chen, DaiZhao,Dong, ShaoFeng,Qian, YiXiong,&Liu, CunGe.(2017).Early dolomitisation of the Lower-Middle Ordovician cyclic carbonates in northern Tarim Basin, NW China.SCIENCE CHINA-EARTH SCIENCES,60(7),1283-1298.
MLA	Guo, Chuan,et al."Early dolomitisation of the Lower-Middle Ordovician cyclic carbonates in northern Tarim Basin, NW China".SCIENCE CHINA-EARTH SCIENCES 60.7(2017):1283-1298.