Windward and leeward margins of an Upper Ordovician carbonate platform in the Central Tarim Uplift, Xinjiang, northwestern China

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 热带海洋环境国家重点实验室(LTO)

	Windward and leeward margins of an Upper Ordovician carbonate platform in the Central Tarim Uplift, Xinjiang, northwestern China
	Zhang, YY; Li, Y; Wang, G; Munnecke, A
刊名	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
	2017
卷号	474 页码:79-88
关键词	Palaeoecologic gradient Palaeogeographic implication Metazoan reef Microbialite Lianglitag Formation
通讯作者	yuanyuanzh85@163.com
中文摘要	In the Central Uplift of the Tarim Basin, northwestern China, the Katian (Upper Ordovician) limestones of the Lianglitag Formation extend from outcrops in the Bachu area to the subsurface in the Tazhong Oil Field (TZOF) area. Reefs and inner platform deposits are the dominant facies throughout the formation. The reef composition illustrates a palaeoecologic gradient from microbial-dominated buildups on the northwestern margin to metazoan-dominated reefs on the eastern and southern margins of the platform. Between these areas no outcrops are present. In the present study, data including litho- and biofacies logs and correlations from eight wells are presented, six of them of the region between Bachu and Tazhong, and two wells along the former platform margin from the TZOF. Calcimicrobial carbonates are common in core from the inner platform part. Benthic biota documented here resembles that of the microbial mounds and bioclastic limestones in the Bachu outcrop area, and thus is considered as the eastward extension of this realm. However, metazoan-dominated boundstones formed by corals, stromatoporoids, sponges together with calcareous algae are abundant along the southern platform margin, and are similar in composition to the reefs of TZOF in the easternmost part of the platform. The palaeoecologic differentiation between microbial- and metazoan-dominated reefs suggests a strong environmental gradient from a well-oxygenated windward eastern and southern side of the platform, which favoured the open ocean and which was dominated by metazoan reefs, and the inner platform as well as the northwestern, leeward margin of the platform with warmer, less-oxygenated water, which favoured the growth of microbial carbonates. Assuming the trade winds as cause for the contrasting facies on both sides of the platform a palaeo-position of Tarim south of the ITCZ seems probable because a position north of it would require a post Ordovician clockwise rotation of Tarim of about 90 which is possible but less probable. Crown Copyright (C) 2017 Published by Elsevier B.V. All rights reserved.
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/16449]
专题	南海海洋研究所_热带海洋环境国家重点实验室(LTO)
推荐引用方式 GB/T 7714	Zhang, YY,Li, Y,Wang, G,et al. Windward and leeward margins of an Upper Ordovician carbonate platform in the Central Tarim Uplift, Xinjiang, northwestern China[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2017,474:79-88.
APA	Zhang, YY,Li, Y,Wang, G,&Munnecke, A.(2017).Windward and leeward margins of an Upper Ordovician carbonate platform in the Central Tarim Uplift, Xinjiang, northwestern China.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,474,79-88.
MLA	Zhang, YY,et al."Windward and leeward margins of an Upper Ordovician carbonate platform in the Central Tarim Uplift, Xinjiang, northwestern China".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 474(2017):79-88.