Characteristics and Dolomitization of Upper Cambrian to Lower Ordovician Dolomite from Outcrop in Keping Uplift, Western Tarim Basin, Northwest China

doi:10.1111/1755-6724.12106

	Characteristics and Dolomitization of Upper Cambrian to Lower Ordovician Dolomite from Outcrop in Keping Uplift, Western Tarim Basin, Northwest China
	Ji Congwei 1,2; Qing Hairuo 2; Chen Daizhao 3; Luo Ping 4; Jin Zhijun 5; Shao Longyi 1
刊名	ACTA GEOLOGICA SINICA-ENGLISH EDITION
	2013-08-01
卷号	87 期号:4 页码:1005-1018
关键词	Dolomitization Lithologic Characteristics Geochemical Characteristics Upper Cambrian-lower Ordovician Keping Uplift
ISSN号	1000-9515
DOI	10.1111/1755-6724.12106
文献子类	Article
英文摘要	Late Cambrian to Early Ordovician sedimentary rocks in the western Tarim Basin, Northwest China, are composed of shallow-marine platform carbonates. The Keping Uplift is located in the northwest region of this basin. On the basis of petrographic and geochemical features, four matrix replacement dolomites and one type of cement dolomite are identified. Matrix replacement dolomites include (1) micritic dolomites (MD1); (2) fine-coarse euhedral floating dolomites (MD2); (3) fine-coarse euhedral dolomites (MD3); and (4) medium-very coarse anhedral mosaic dolomites (MD4). Dolomite cement occurs in minor amounts as coarse saddle dolomite cement (CD1) that mostly fills vugs and fractures in the matrix dolomites. These matrix dolomites have O-18 values of -9.7 parts per thousand to -3.0 parts per thousand VPDB (Vienna Pee Dee Belemnite); C-13 values of -0.8 parts per thousand to 3.5 parts per thousand VPDB; Sr-87/Sr-86 ratios of 0.708516 to 0.709643; Sr concentrations of 50 to 257 ppm; Fe contents of 425 to 16878 ppm; and Mn contents of 28 to 144 ppm. Petrographic and geochemical data suggest that the matrix replacement dolomites were likely formed by normal and evaporative seawater in early stages prior to chemical compaction at shallow burial depths. Compared with matrix dolomites, dolomite cement yields lower O-18 values (-12.9 parts per thousand to -9.1 parts per thousand VPDB); slightly lower C-13 values (-1.6 parts per thousand-0.6 parts per thousand VPDB); higher Sr-87/Sr-86 ratios (0.709165-0.709764); and high homogenization temperature (Th) values (98 degrees C-225 degrees C) and salinities (6 wt%-24 wt% NaCl equivalent). Limited data from dolomite cement shows a low Sr concentration (58.6 ppm) and high Fe and Mn contents (1233 and 1250 ppm, respectively). These data imply that the dolomite cement precipitated from higher temperature hydrothermal salinity fluids. These fluids could be related to widespread igneous activities in the Tarim Basin occurring during Permian time when the host dolostones were deeply buried. Faults likely acted as important conduits that channeled dolomitizing fluids from the underlying strata into the basal carbonates, leading to intense dolomitization. Therefore, dolomitization, in the Keping Uplift area is likely related to evaporated seawater via seepage reflux in addition to burial processes and hydrothermal fluids.
WOS关键词	CANADA SEDIMENTARY BASIN ; DEVONIAN PRESQUILE BARRIER ; FLUID-FLOW EVENTS ; SADDLE DOLOMITE ; NW CHINA ; RESERVOIR ; EVOLUTION ; CARBONATES ; GEOCHEMISTRY ; ACCUMULATION
WOS研究方向	Geology
语种	英语
出版者	WILEY-BLACKWELL
WOS记录号	WOS:000323744100009
资助机构	PetroChina(09HT10500000068) ; PetroChina(09HT10500000068) ; Sinopec(G5800-07-ZS-WX032) ; Sinopec(G5800-07-ZS-WX032) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; PetroChina(09HT10500000068) ; PetroChina(09HT10500000068) ; Sinopec(G5800-07-ZS-WX032) ; Sinopec(G5800-07-ZS-WX032) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; PetroChina(09HT10500000068) ; PetroChina(09HT10500000068) ; Sinopec(G5800-07-ZS-WX032) ; Sinopec(G5800-07-ZS-WX032) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; PetroChina(09HT10500000068) ; PetroChina(09HT10500000068) ; Sinopec(G5800-07-ZS-WX032) ; Sinopec(G5800-07-ZS-WX032) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801) ; State Key Lab of Oil/Gas Reservoir Geology and Exploitation at CDUT(PLC200801)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86350]
专题	中国科学院地质与地球物理研究所
通讯作者	Shao Longyi
作者单位	1.China Univ Min & Technol, Dept Geol, Beijing 100083, Peoples R China 2.Univ Regina, Dept Geol, Regina, SK S4S 0A2, Canada 3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 4.Petrochina, Inst Petr Explorat & Dev, Beijing 100083, Peoples R China 5.Sinopec, Inst Petr Explorat & Dev, Beijing 100037, Peoples R China
推荐引用方式 GB/T 7714	Ji Congwei,Qing Hairuo,Chen Daizhao,et al. Characteristics and Dolomitization of Upper Cambrian to Lower Ordovician Dolomite from Outcrop in Keping Uplift, Western Tarim Basin, Northwest China[J]. ACTA GEOLOGICA SINICA-ENGLISH EDITION,2013,87(4):1005-1018.
APA	Ji Congwei,Qing Hairuo,Chen Daizhao,Luo Ping,Jin Zhijun,&Shao Longyi.(2013).Characteristics and Dolomitization of Upper Cambrian to Lower Ordovician Dolomite from Outcrop in Keping Uplift, Western Tarim Basin, Northwest China.ACTA GEOLOGICA SINICA-ENGLISH EDITION,87(4),1005-1018.
MLA	Ji Congwei,et al."Characteristics and Dolomitization of Upper Cambrian to Lower Ordovician Dolomite from Outcrop in Keping Uplift, Western Tarim Basin, Northwest China".ACTA GEOLOGICA SINICA-ENGLISH EDITION 87.4(2013):1005-1018.