检索结果-南通市图书馆

Re-Os Geochronology of the liuchapo formation across the Ediacaran-Cambrian Boundary of the Yangtze Block(South China)

引用

Journal of Earth Science 2022年第1期33卷 25-35页

作者： Yong Fu Fuliang Wang Chuan Guo Chao Li Peng Xia College of Resource and Environmental Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Karst Georesources and Environment Ministry of EducationGuizhou UniversityGuiyang 550025China Guizhou Geological Environment Monitoring Institute Guizhou 550081China National Research Center for Geoanalysis Chinese Academy of Geological SciencesBeijing 100037China

The Ediacaran-Cambrian(E-C) succession in South China records remarkable oceanic,biological and geochemical variations,but it was not well defined geochronologically,which hinders the interpretation of the spatio-temporal seawater chemical architecture during the time E-C interval.This study presents two Re-Os isochron ages of 520.2±6.1 and 561.7±8.5 Ma for the barite-rich black shales from the top liuchapo and Doushantuo formations respectively in Tianzhu County,Guizhou Province.In combination with existing age data,the two new Re-Os isochron ages suggest that the liuchapo formation was deposited between 550 and 520 Ma.Moreover,like the polymetallic Ni-MoPGE layers of shelf margin(or platform) facies and V-rich horizons of transitional(or shelf slope) to deep-water facies,the barite deposits were likely formed due to differential mineralization.The timing offset likely resulted from differential elemental concentration related to certain local factors(i.e.,hydrothermal fluids,seawater redox and biological activity).The isochron-derived initial ^(187)Os/^(188)Os ratios of the top liuchapo formation(0.902 ± 0.048) and the Doushantuo formation(0.740 ± 0.042) fall within the range of continental weathering flux(1.54) and oceanic crust(0.126),implying the involvement of marine hydrothermal fluids.Moreover,their difference of initial ^(187)Os/^(188)Os ratios may reflect variations of continental weathering intensity and uplift magnitude.

关键词： geochemistry Ediacaran-Cambrian initial^(187)Os/^(188)Os liuchapo formation Re-Os isotope Yangtze Block

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Diverse Microfossil Assemblage from the Ediacaran–Cambrian Deep-Water Chert of the liuchapo formation in Guizhou Province,South China

引用

Journal of Earth Science 2023年第2期34卷 398-408页

作者： Yan Zhang Shan Chang Qinglai Feng Shucan Zheng State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China School of Earth Sciences China University of GeosciencesWuhan 430074China College of Urban and Environmental Sciences Hubei Normal UniversityHuangshi 435002China School of Architectural Engineering Huanggang Normal UniversityHuanggang 438000China

The Ediacaran to Cambrian transition witnessed great biological and environmental turnovers from the Precambrian to Phanerozoic.These changes are also reflected by the fossil records during that time.However,the fossil distribution was highly heterogenous.While diverse fossils were constantly found from the shallow shelf including restricted basins,reports from deep-water areas,which are characterized by chert-dominated formations straddling the Ediacaran-Cambrian boundary,were scarce.Among them was the liuchapo formation that has been considered barren.In this study,a fossiliferous assemblage was found from the liuchapo formation in east Guizhou Province,South China.This assemblage comprises Palaeopascichnus jiumenensis,Horodyskia minor,multicellular algae that possibly related with red algae,cyanobacteria,sponge spicules,small shelly fossils,membrane structures of uncertain affinity,and fossils with structures resemble the Ediacaran Megasphaera.Palaeopascichnus and Horodyskia have been widely reported and abundant in the liuchapo formation and equivalents,while the others have seldomly,or never,been found from this formation or,more widely,the deep-water chert of transitional interval.The discovery not only contributes to the rare paleontological records preserved in deep-water sediments,but also expanded the geographic distribution of the fossils,providing new materials of biological diversity during this critical interval.

关键词： liuchapo formation Early Cambrian latest Ediacaran deep-water chert fossils paleobiology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Constraints on the Ediacaran-Cambrian boundary in deep-water realm in South China: Evidence from zircon CA-ID-TIMS U-Pb ages from the topmost liuchapo formation

引用

Science China Earth Sciences 2020年第8期63卷 1176-1187页

作者： Wei WANG Mingzhong ZHOU Zhuyin CHU Junjie XU Chaofeng LI Taiyi LUO Jinghui GUO State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China School of Geographical and Environmental Sciences Guizhou Normal UniversityGuiyang 550001China:China University of GeosciencesBeijing 100083China:State Key Laboratory of Ore Deposit GeochemistryInstitute of GeochemistryChinese Academy of SciencesGuiyang 550002China

The placement of the Ediacaran-Cambrian boundary in deep-water realm in South China and the high-precision temporal framework for the Ediacaran-Cambrian transition in this region have not yet been completely solved. Recently, we have found two K-bentonite beds in the top of the liuchapo formation at the Pingyin section, Guizhou Province. It provides an opportunity for constructing the temporal framework of the transitional strata on the Yangtze Platform in South China and for determining the Ediacaran-Cambrian boundary in this area. In this study, we conducted high-precision CA-ID-TIMS U-Pb dating on zircons from the two K-bentonites. The ages of the two K-bentonites were precisely constrained at 536.40±0.47/1.1/1.2 Ma(2σ, n=7, MSWD=0.92) and 541.48±0.46/1.1/1.2 Ma(2σ, n=8, MSWD=1.3). Combining the geochronological results with organic carbon isotope data of chert in the topmost liuchapo formation from the section, we suggest that the EdiacaranCambrian boundary should be consistent with a significant negative organic carbon isotope excursion between the two Kbentonites. The scheme of the Ediacaran-Cambrian boundary in this study is of great significance for global correlation, and further for unravelling the information of the terminal Ediacaran-early Cambrian ocean.

关键词： liuchapo formation Yangtze Platform Ediacaran-Cambrian CA-ID-TIMS Organic carbon isotope

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：