DOI: 10.1016/j.palaeo.2015.11.029
论文题名: Paleo-marine environments of the Early Cambrian Yangtze Platform
作者: Zhang J. ; Fan T. ; Algeo T.J. ; Li Y. ; Zhang J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 443 起始页码: 66
结束页码: 79
语种: 英语
英文关键词: Corg:P ratios
; Environmental change
; Molybdenum
; Redox conditions
; Trace elements
; Uranium
英文摘要: Previous studies have generated conflicting interpretations of the nature of oceanographic conditions on the Early Cambrian Yangtze Platform. We investigated paleo-environmental conditions there through an analysis of major elements and redox-sensitive trace elements in the lower Cambrian Niutitang Formation from two new drillcores (RY1 and RY2) in Guizhou Province. High TOC and excess Ba concentrations record elevated productivity in the study area. Redox variation was documented based on enrichment factors (EFs) for redox-sensitive trace elements (Mo, U, V, Cr, Ni, and Co) and Corg:P ratios. These proxies indicate that the Lower Unit of the Niutitang Formation was deposited under fluctuating but mostly anoxic conditions, whereas the Upper Unit was deposited under predominantly suboxic conditions. Mo/TOC ratios suggest persistently moderate to strong basinal restriction, although Mo-U covariation patterns show no evidence for operation of a particulate shuttle despite the semi-restricted, anoxic nature of the deep watermass. Episodic deep water oxygenation events occurred within the Yangtze Platform sea, and longer-term secular variation may record eustatic influences. Additionally, patterns of trace-metal enrichment record evidence of submarine hydrothermal inputs. We propose an integrated paleoenvironmental model to account for the observed productivity, redox, and hydrographic patterns in the Early Cambrian Yangtze Platform. On the basis of paleo-marine environmental analysis, we ascribe the scarcity of trace fossils in the bottom to oxygen deficiency, and deny considering the Songlin Biota as the onset of the intense biogenic evolution after global atmospheric and oceanic oxygenation. © 2015 Elsevier B.V.. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68599
Appears in Collections: 过去全球变化的重建
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作者单位: School of Energy Sources, China University of Geosciences, Haidian, Beijing, China; Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism, Ministry of Education, China University of Geosciences, Beijing, China; Department of Geology, University of Cincinnati, Cincinnati, OH, United States; State Key Laboratories of BGEG and GPMR, China University of Geosciences, Wuhan, China
Recommended Citation:
Zhang J.,Fan T.,Algeo T.J.,et al. Paleo-marine environments of the Early Cambrian Yangtze Platform[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,443