Climate Change Data Portal
DOI | 10.1016/j.palaeo.2018.01.019 |
Volcanic sources and diagenetic alteration of Permian–Triassic boundary K-bentonites in Guizhou Province; South China | |
Hong H.; Zhao L.; Fang Q.; Algeo T.J.; Wang C.; Yu J.; Gong N.; Yin K.; Ji K. | |
发表日期 | 2019 |
ISSN | 0031-0182 |
起始页码 | 141 |
结束页码 | 153 |
卷号 | 519 |
英文摘要 | Terrestrial Permian–Triassic boundary (PTB) sequences in South China usually contain one to three ash beds (K-bentonites), which provide evidence of a possible trigger for the terrestrial mass extinction and are useful as a distinct marker for correlation of the PTB boundary interval from terrestrial to marine areas. Here, we investigate the clay mineralogy and geochemistry of ash beds in the Zhejue and Jiucaichong sections, representing paludal and lacustrine environments, respectively, in order to better understand the source(s) and preservation of these ash beds. The two Zhejue K-bentonites exhibit similar compositions that are distinctly different from that of the Jiucaichong K-bentonite. The former contain mainly clay minerals with minor quartz, anatase, and lepidocrocite, and the clay minerals in these layers are mainly R1 and R3 mixed-layer illite/smectite (I/S) and well-crystallized to poorly-crystallized kaolinite, whereas the latter consists mainly of R3 I/S with minor quartz, feldspars, and anatase. The former have higher CIA values (92.2 and 93.8) than the latter (79.4), indicating more intense chemical weathering that may have been related to deposition in a paludal setting with high organic acid concentrations in pore fluids. These K-bentonites also exhibit differences in major-element chemistry (MgO and K 2 O contents are higher at Jiucaichong due to lesser weathering intensity and, possibly, early diagenetic uptake from pore fluids), REE chemistry (Jiucaichong exhibits a larger Eu anomaly), and Nd isotopic compositions (Zhejue K-bentonites have 143 Nd/ 144 Nd ratios of 0.512436 and 0.512400, higher than the 0.512190 ratio for Jiucaichong). Although some of these compositional differences may be related to the dissimilar chemical environments in which diagenesis occurred (i.e., paludal vs lacustrine), the differences in Eu anomalies and Nd isotopic compositions imply heterogeneous volcanic ash sources. The source of these K-bentonites was probably a continental volcanic arc located on the paleo-southern margin of the South China Craton, within which multiple volcanic vents may have been active concurrently. © 2018 Elsevier B.V. |
英文关键词 | Kaolinite; Lacustrine; Mixed-layer; Paludal; Rare earth elements; Tephra |
语种 | 英语 |
scopus关键词 | bentonite; chemical composition; chemical weathering; clay mineral; diagenesis; geochemistry; isotopic composition; kaolinite; lacustrine environment; lepidocrocite; mass extinction; mixed layer; Permian-Triassic boundary; rare earth element; tephra; terrestrial environment; volcanic ash; China; Guizhou |
来源期刊 | Palaeogeography, Palaeoclimatology, Palaeoecology
![]() |
文献类型 | 期刊论文 |
条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/151050 |
作者单位 | School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei 430074, China; Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013, United States; Gemmological Institute, China University of Geosciences, Wuhan, 430074, China |
推荐引用方式 GB/T 7714 | Hong H.,Zhao L.,Fang Q.,等. Volcanic sources and diagenetic alteration of Permian–Triassic boundary K-bentonites in Guizhou Province; South China[J],2019,519. |
APA | Hong H..,Zhao L..,Fang Q..,Algeo T.J..,Wang C..,...&Ji K..(2019).Volcanic sources and diagenetic alteration of Permian–Triassic boundary K-bentonites in Guizhou Province; South China.Palaeogeography, Palaeoclimatology, Palaeoecology,519. |
MLA | Hong H.,et al."Volcanic sources and diagenetic alteration of Permian–Triassic boundary K-bentonites in Guizhou Province; South China".Palaeogeography, Palaeoclimatology, Palaeoecology 519(2019). |
条目包含的文件 | 条目无相关文件。 |
个性服务 |
推荐该条目 |
保存到收藏夹 |
导出为Endnote文件 |
谷歌学术 |
谷歌学术中相似的文章 |
[Hong H.]的文章 |
[Zhao L.]的文章 |
[Fang Q.]的文章 |
百度学术 |
百度学术中相似的文章 |
[Hong H.]的文章 |
[Zhao L.]的文章 |
[Fang Q.]的文章 |
必应学术 |
必应学术中相似的文章 |
[Hong H.]的文章 |
[Zhao L.]的文章 |
[Fang Q.]的文章 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。