Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.jseaes.2016.08.019 |
Climatic-oceanic forcing on the organic accumulation across the shelf during the Early Cambrian (Age 2 through 3) in the mid-upper Yangtze Block, NE Guizhou, South China | |
Yeasmin, Rumana1,2; Chen, Daizhao1; Fu, Yong3; Wang, Jianguo1; Guo, Zenghui1; Guo, Chuan1 | |
通讯作者 | Chen, Daizhao |
来源期刊 | JOURNAL OF ASIAN EARTH SCIENCES
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ISSN | 1367-9120 |
EISSN | 1878-5786 |
出版年 | 2017 |
卷号 | 134页码:365-386 |
英文摘要 | The organic-rich sediments were widely deposited over the entire Yangtze Block during the Early Cambrian (late Nemakit-Daldynian to Botomian). In the mid-upper Yangtze region, northeastern Guizhou, South China, they comprise, in ascending order, the Niutitang, Jiumenchong and lower Bianmachong formations which are dominated by black shales except the middle one characterized by interbedded shales-limestones. Three third-order depositional sequences are identified in the two studied sections located on the upper slope to basin of the open shelf. The organic-rich sediments were mostly deposited notably during transgressions on the shallower upper slope-margin (TOC up to 25 wt.%) where they are characterized by co-increases in C, P, Fe, and Ba concentrations, indicating the highest organic productivity and coupled C, P and Fe cycling there. In contrast, in the shelf basin, the concomitant organic-rich sediments yield lower organic (TOC <10 wt.% mostly) and Ba abundances, and generally show antithetic relationship of TOC with P and Fe variations, indicative of a relatively low organic productivity and transient decoupled C, P and Fe cycling in the deeper basin. This spatial difference in C, P, Fe and Ba cycling as a whole thus indicate that the highest organic productivity wedge on the shallower shelf upper slope-margin was likely induced by the oceanic upwelling from the restricted basin where the P and Fe nutrients were transiently depleted without timely renewal. Meanwhile, multiple redox proxies, including V/Al, Ni/Al and Cr/Al ratios vs. TOC contents, together with V/(V + Ni) and V/Cr ratios, generally characterize a more severe euxinic water wedge localized on the shallower upper slope-margin of shelf where the organic production culminated, but a nonsulfidic (ferruginous) anoxic state in the basin due to the relatively low sulfate level. Meanwhile, episodic depletion of trace elements in the deeper basin during the higher organic productivity also reconciles the concomitantly enhanced upwelling from the somewhat restricted deep watermass likely silled by the underwater upland seaward. The coincidence of organic-rich intervals with more arid climate epoches, as shown by increased Ti/Al ratios indicative of increased aeolian fluxes, reconciles a subtropical arid climate of Yangtze Block within the north mid-low-latitude trade-wind zone during deposition (the Early Cambrian). As such, enhanced offshore currents driven by the trade winds could have further induced the upwelling of nutrient-rich deep waters along the shelf during the transgressions, although tended to wane onwards, leading to the tempo-spatial heterogeneities in organic production and redox state across the shelf sea. (C) 2016 Elsevier Ltd. All rights reserved. |
英文关键词 | Early Cambrian Organic enrichment Primary productivity and redox state Oceanic upwelling Climatic-oceanic forcing Yangtze Block |
类型 | Article |
语种 | 英语 |
国家 | Peoples R China ; Bangladesh |
收录类别 | SCI-E |
WOS记录号 | WOS:000392767200026 |
WOS关键词 | MARINE BIOGEOCHEMICAL CYCLES ; BIOGENIC BARIUM FLUXES ; PB ZIRCON AGES ; BLACK SHALES ; ELEMENT GEOCHEMISTRY ; CARBON PRESERVATION ; SULFATE REDUCTION ; REDOX CONDITIONS ; XIAOTAN SECTION ; TRACE-METALS |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
来源机构 | 中国科学院地质与地球物理研究所 |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/200194 |
作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, Beijing 100029, Peoples R China; 2.Jahangirnagar Univ, Dept Geol Sci, Dhaka 1342, Bangladesh; 3.Guizhou Univ, Coll Resources & Environm Engn, Guiyang 550012, Peoples R China |
推荐引用方式 GB/T 7714 | Yeasmin, Rumana,Chen, Daizhao,Fu, Yong,et al. Climatic-oceanic forcing on the organic accumulation across the shelf during the Early Cambrian (Age 2 through 3) in the mid-upper Yangtze Block, NE Guizhou, South China[J]. 中国科学院地质与地球物理研究所,2017,134:365-386. |
APA | Yeasmin, Rumana,Chen, Daizhao,Fu, Yong,Wang, Jianguo,Guo, Zenghui,&Guo, Chuan.(2017).Climatic-oceanic forcing on the organic accumulation across the shelf during the Early Cambrian (Age 2 through 3) in the mid-upper Yangtze Block, NE Guizhou, South China.JOURNAL OF ASIAN EARTH SCIENCES,134,365-386. |
MLA | Yeasmin, Rumana,et al."Climatic-oceanic forcing on the organic accumulation across the shelf during the Early Cambrian (Age 2 through 3) in the mid-upper Yangtze Block, NE Guizhou, South China".JOURNAL OF ASIAN EARTH SCIENCES 134(2017):365-386. |
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