DOI: 10.1016/j.gloplacha.2015.06.009
论文题名: Lower Triassic anachronistic facies capping the Qinghai-Tibet Plateau seamount: Implications for the extension of extraordinary oceanic conditions deep into the interior Tethys Ocean
作者: Deng B. ; Wang Y. ; Woods A. ; Li G. ; Liao W.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 132 起始页码: 31
结束页码: 38
语种: 英语
英文关键词: Anachronistic facies
; Bayan Har
; Early Triassic
; Seamount
Scopus关键词: Carbonates
; Carbonation
; Quartz
; Volcanoes
; Anachronistic facies
; Bayan Har
; Microbial carbonates
; Qinghai Tibet plateau
; Qinghai-Tibetan plateau
; Seamount
; Shallow water carbonates
; Triassic
; Submarine geology
; basin analysis
; carbonate platform
; carbonate rock
; deep water
; facies
; flysch
; foraminifera
; paleoceanography
; quartz
; seamount
; shallow water
; synchrony
; tectonic setting
; Tethys
; Triassic
; volcanic eruption
; warm water
; Bayan Har Mountains
; China
; Qinghai
; Qinghai-Xizang Plateau
; Foraminifera
英文摘要: The Bayan Har area, situated in the northeast of the Qinghai-Tibetan Plateau, has long been regarded as a deep-water turbidite basin during Early Triassic. However, a sequence of Lower Triassic shallow-water carbonate rocks has been documented from the region, indicating the existence of isolated seamount carbonate platforms in the basin. The seamount carbonate platform sediments differ from synchronous deep basin flysch sediments, and consist of shallow-water oncoids, ooids and cortoids. Microfacies studies reveal that the oncoids have a thick cortex comprised of irregular, non-concentric and partially overlapping micritic laminae and contain abundant well-preserved foraminifera, indicating a relatively low-energy environment in subtidal settings. Ooids exhibit thinner and more regular concentric laminations, which are interpreted to have formed by frequent overgrowth while rolling in a relatively high-energy setting. Cortoids are predominantly composed of tiny fossil fragments and intraclasts with a micritic envelope, indicating a shallow-marine warm water environment located in the intertidal or supertidal zone. Ooids in the Bayan Har area differ from those found on stable platforms, in that they sometimes nucleated onto volcanic quartz grains, reflecting an unstable tectonic setting that was frequently affected by volcanic activity. Widespread ooids and other microbial carbonates formed in the Early Triassic have been regarded anachronistic facies that are indicative of harsh marine conditions. Most Lower Triassic anachronistic facies are distributed along the shallow margin of the Tethys Ocean and the western margin of Pangea; however, Bayan Har was located in the center of the Palaeo-Tethys. The discovery of oncoids and oolites capping a seamount in this area provides strong evidence that extraordinary marine conditions spread far into the interior of the Palaeo-Tethys Ocean. © 2015 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84934281795&doi=10.1016%2fj.gloplacha.2015.06.009&partnerID=40&md5=545aecd7c4190d05aa6807f419b9b42a
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11501
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan, China
Recommended Citation:
Deng B.,Wang Y.,Woods A.,et al. Lower Triassic anachronistic facies capping the Qinghai-Tibet Plateau seamount: Implications for the extension of extraordinary oceanic conditions deep into the interior Tethys Ocean[J]. Global and Planetary Change,2015-01-01,132.