Depositional Setting and Tectonic Background Analysis on Lower Cambrian Black Shales in the North of Guizhou Province
详细信息
- 责任者：Li Juan (State Key Laboratory of Geological Process and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yu Bingsong
- 刊名：Acta Sedimentologica Sinica
- 出版年：2013
- 卷期：31(1)
- 关键词：黑色页岩 ; black shale ; 沉积环境 ; sedimentary environment ; 贵州 ; Guizhou Province
- 页码：p.20-31
- 图表：illus., 5 tables, 42 refs.
- 分类号：0803
- issnNo：ISSN1000-0550
- isbnNo：CN62-1038/P
摘要
In order to discuss depositional setting and its tectonic background of the black shale and on the base of the researched 20 profiles,the authors chose 20 samples collected from bottom of lower Cambrian in the north of Guizhou Province to test and analyze clay minerals,X-ray diffraction of the rock minerals and trace elements(including REE). Current study shows that the main minerals are quartz whose average content are 55.75%,and clay minerals whose average content are 28.35%,Among which,the average content of illite is 59%,and the main aeceasory mineral is pyrite in the bottom of lower Cambrian in the north of Guizhou Province;ΣREE is very high and the differentiation between LREE and HREE is distinct which LREE is enriched and Eu is postive anomaly and Ce is negative anomaly;the average ratio of W V /(W Ni + W V) and U/Th is respectively 0.78 and 3.76 and the depleted Ce together reflect that Black shale in the north of Guizhou Province forms in reduction environment with stable crust,transgression sea climax and open sea area;the enrichment of trace elements Mo,Sb,U,Cd,V,Ba,Tl,Ni,W,Cr,Cs,Cu,Zn,Bi,strongly depleted Sr,Re,positive Eu anomaly and the lower Co / Zn ratio of the Black shale in the north of Guizhou Province are most likely due to a hydrothermal input;.By the contrast of major elements,trace elements and REE parameters,a conclusion can drawn that in research areas source rocks are mainly sedimentary rocks and granitic rocks with a few locally-involved basalt components,the tectonic setting is mainly passive continental margin and partly continental island arc because of hydrothermal input.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |