Geochemical Characteristics and Sedimentary Environment of Lower Cambrian Greywacke in Southwestern Jiangxi Province

详细信息   

• 责任者：Zheng Ning (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Liu Yanxue
• 刊名：Geological Bulletin of China
• 出版年：2012
• 卷期：31(7)
• 关键词：砂岩 ; sandstone ; 沉积环境 ; sedimentary environment ; 江西 ; Jiangxi Province
• 页码：p.1115-1125
• 图表：5 illus., 5 tables, 34 refs.
• 分类号：0803
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

摘要

In Lower Cambrian,thick sandy and muddy flysch deposits were distributed in the southwestern Jiangxi Province. This paper is focused on the compositions and assemblages of major, trace and rare earth elements of greywacke in Ganzhou, Jinggangshan and Pingxiang.The studies show that the greywacke has relatively high SiO₂ content, high Al₂O₃/（CaO＋Na₂O）ratios and K₂O/Na₂O ratios, and comparatively low Al₂O₃/SiO₂ ratios and Fe₂O₃/MgO ratios as well as lower CaO content. The trace earth elements are similar to those in the upper crust of eastern China, with the enrichment of the large ion radius elements. The rare earth elements are characterized by rich LREE and obvious negative Eu anomaly. It is held that the provenance was from Cathaysia Block. Geochemical characteristics indicate that the northern edge of this area belonged to a passive continental-margin tectonic environment.