A Middle Ordovician (Darriwilian) Calathium reef complex on the carbonate ramp of the northwestern Tarim Block, northwest China: A sedimentological approach

doi:10.1016/j.palaeo.2016.11.002

	A Middle Ordovician (Darriwilian) Calathium reef complex on the carbonate ramp of the northwestern Tarim Block, northwest China: A sedimentological approach
	Wang, JP (王建坡); Li, Y (李越); Zhang, YY (张园园); Kershaw, S
	2017
发表期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN	0031-0182
卷号	474 期号:SI 页码:58-65
摘要	Middle Ordovician carbonates are exposed for 25 km along the Lianglitag Mountains in the Tarim Basin, northwest China. They reflect platform carbonate and reef deposition along the ancient Central Tarim Uplift. The Darriwilian Yijianfang Formation, similar to 70 m thick, was deposited in a shallow carbonate ramp setting, deepening seaward to the north in current geography. Reefal and biostromal units are constructed primarily by sessile Calathium of possible sponge affinity in the Middle Member of the formation. Patch reefs, similar to 10 m in thickness and tens of meters in diameter, are common in the northern region. Associated shelly faunas, including trilobites, bivalves, and brachiopods, are diverse and preserved as coarse bioclastic materials together with intraclasts. Towards the south, patch reefs are smaller, <1 m in thickness and with low relief. A biostrome formed by in situ Calathium framework is interpreted to act as a baffle for fine sediments, with smaller amounts of bioclasts and intraclasts. The biostrome is only similar to 3 m thick in the southernmost section suggesting a calmer leeward setting initially. Tempestite beds composed of Calathium and nautiloid floatstones are abundant through the section, with monospecific brachiopod layers in the tempestite beds. This work demonstrates previously unrecognized paleogeographic variations of the Darriwilian Calathium reef complexes, which have larger patch reefs generally developing in the north area, smaller patch reefs dominating southward, and biostromes occurring in the southernmost locations. The reef complex was drowned due to sea-level rise, which is recorded in the upper Yijianfang Formation. (C) 2016 Elsevier B.V. All rights reserved.
关键词	Morphological variation Reef complex Yijianfang formation Bachu Northwest China
DOI	10.1016/j.palaeo.2016.11.002
收录类别	SCI
语种	英语
WOS研究方向	Physical Geography ; Geology ; Paleontology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS记录号	WOS:000399261500006
出版者	ELSEVIER SCIENCE BV
文献类型	期刊论文
条目标识符	http://ir.nigpas.ac.cn/handle/332004/13636
专题	中国科学院南京地质古生物研究所中国科学院南京地质古生物研究所其他
通讯作者	Li, Y (李越)
推荐引用方式 GB/T 7714	Wang, JP ,Li, Y ,Zhang, YY ,et al. A Middle Ordovician (Darriwilian) Calathium reef complex on the carbonate ramp of the northwestern Tarim Block, northwest China: A sedimentological approach[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017,474(SI):58-65.
APA	Wang, JP ,Li, Y ,Zhang, YY ,&Kershaw, S.(2017).A Middle Ordovician (Darriwilian) Calathium reef complex on the carbonate ramp of the northwestern Tarim Block, northwest China: A sedimentological approach.Palaeogeography, Palaeoclimatology, Palaeoecology,474(SI),58-65.
MLA	Wang, JP ,et al."A Middle Ordovician (Darriwilian) Calathium reef complex on the carbonate ramp of the northwestern Tarim Block, northwest China: A sedimentological approach".Palaeogeography, Palaeoclimatology, Palaeoecology 474.SI(2017):58-65.