Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China)

doi:10.1016/j.jseaes.2018.02.006

	Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China)
	Guo, Chuan 1; Chen, Daizhao 1,2; Song, Yafang 1,2; Zhou, Xiqiang 1; Ding, Yi 1,2; Zhang, Gongjing 1,2
	2018-06-01
发表期刊	JOURNAL OF ASIAN EARTH SCIENCES
ISSN	1367-9120
卷号	158 页码:29-48
文章类型	Article
摘要	During the Early Ordovician, the Tarim Basin (NW China) was mainly occupied by an extensive shallow-water carbonate platform, on which a carbonate ramp system was developed in the Bachu-Keping area of the western part of the basin. Three well-exposed typical outcrop sections of the Lower Ordovician Penglaiba Formation were investigated in order to identify the depositional facies and to clarify origins of meter-scale cycles and depositional sequences, thereby the platform evolution. Thirteen lithofacies are identified and further grouped into three depositional fades (associations): peritidal, restricted and open-marine subtidal fades. These lithofacies are vertically stacked into meter-scale, shallowing-upward peritidal and subtidal cycles. The peritidal cycles are mainly distributed in the lower and uppermost parts of the Penglaiba Formation deposited in the inner-middle ramp, and commonly start with shallow subtidal to intertidal facies followed by inter- to supratidal fades. In contrast, the subtidal cycles occur throughout the formation mostly in the middle-outer ramp and are dominated by shallow to relatively deep (i.e., intermediate) subtidal fades. The dominance of asymmetrical and incomplete cycles suggests a dominant control of Earth's orbital forcing on the cyclic deposition on the platform. On the basis of vertical facies and cycle stacking patterns, and accommodation changes illustrated by the Fischer plots from all studied sections, five third-order depositional sequences are recognized in the Penglaiba Formation. Individual sequences comprise a lower transgressive part and an upper regressive one. In shallow-water depositional environments, the transgressive packages are dominated by thicker-than-average subtidal cycles, indicating an increase in accommodation space, whereas regressive parts are mainly represented by thinner than-average peritidal and subtidal cycles, denoting a decrease in accommodation space. In contrast, in intermediate to deep subtidal environments, transgressive and regressive packages display an opposite trend in accommodation space changes. Sequence boundaries (except the basal and top boundaries of the Penglaiba Formation) are usually represented by laterally traceable, transitional boundary zones without apparent sub aerial exposure features. Good correlation of the long-term changes in accommodation space (or sea-level) inferred from vertical stacking patterns of facies and cycles suggests an overriding eustatic control on the formation of meter-scale cycles and third-order depositional sequences as well as platform evolution superimposed with local and/or regional tectonic influence during the Early Ordovician. This study would help understand the controls on the tempo-spatial facies distribution, stratal cyclicity and carbonate platform evolution in the western Tarim Basin during the Early Ordovician, facilitating prediction for favorable subsurface carbonate reservoirs and future hydrocarbon exploration and production in the Penglaiba Formation.
关键词	Carbonate platform Facies High-frequency cycles and sequences Lower Ordovician Penglaiba Formation Tarim Basin
WOS标题词	Science & Technology ; Physical Sciences
DOI	10.1016/j.jseaes.2018.02.006
资助者	National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118)
关键词[WOS]	SULTANATE-OF-OMAN ; SEA-LEVEL CHANGES ; SEQUENCE STRATIGRAPHY ; STACKING PATTERNS ; HIGH-FREQUENCY ; SOUTH CHINA ; VIRGINIA APPALACHIANS ; FACIES ARCHITECTURE ; ESCAPE STRUCTURES ; FISCHER PLOTS
收录类别	SCI
语种	英语
资助者	National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118) ; National Natural Science Foundation of China(U1663209 ; National Natural Science Foundation of China(U1663209 ; 41502117 ; 41502117 ; 41502118) ; 41502118)
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000431469600003
出版者	PERGAMON-ELSEVIER SCIENCE LTD
引用统计
文献类型	期刊论文
条目标识符	http://ir.iggcas.ac.cn/handle/132A11/88319
专题	油气资源研究院重点实验室
通讯作者	Chen, Daizhao
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, 19 Beitucheng Xilu, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Guo, Chuan,Chen, Daizhao,Song, Yafang,et al. Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China)[J]. JOURNAL OF ASIAN EARTH SCIENCES,2018,158:29-48.
APA	Guo, Chuan,Chen, Daizhao,Song, Yafang,Zhou, Xiqiang,Ding, Yi,&Zhang, Gongjing.(2018).Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China).JOURNAL OF ASIAN EARTH SCIENCES,158,29-48.
MLA	Guo, Chuan,et al."Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China)".JOURNAL OF ASIAN EARTH SCIENCES 158(2018):29-48.