%0 Journal Article %T 赣南地区寒武纪沉积岩地球化学特征及其地质意义
The Geochemical Characteristics and Their Geological Significance of Sedimentary Rocks from Cambrian in Gannan Area %A 徐文坦 %A 马虎超 %A 龚安州 %A 杨圣都 %A 黎家强 %A 周博文 %J Advances in Geosciences %P 557-570 %@ 2163-3975 %D 2019 %I Hans Publishing %R 10.12677/AG.2019.96060 %X
赣南地区是华南东段的重要组成部分,寒武纪时期沉积了一套巨厚的复理石建造,它们都具有高SiO2(66.07%~83.85%),相对较高的Al2O3(8.81%~22.56%)、K2O(1.27%~6.72%)和TFeO+MgO(2.17%~9.18%)含量,相对较低的Na2O和CaO含量。微量元素和稀土元素显示相容元素和轻稀土元素相对富集,与典型上地壳元素特征相似。稀土元素球粒陨石标准化分布图显示稀土元素具有明显右倾性,具有明显的Eu负异常和弱Ce负异常,与PASS和上地壳特征相似。岩石地球化学特征结合寒武纪碎屑锆石年代学和Hf同位素特征显示研究区物源主要来自华夏地块南部上地壳长英质源区,少量基性火山岩区和古老地壳再循环的产物。研究区寒武纪时沉积物源没有发生明显变化。研究区早古生代沉积构造背景为被动大陆边缘。
Gannan area is an important part of the eastern part of South China. During the Cambrian, a thick set of flysch formation was deposited. The geochemical characteristics of the sedimentary rocks indicate that they all have high SiO2 (66.07~83.85 wt%), relatively high Al2O3 (8.81~22.56 wt%), K2O (1.27~6.72 wt%) and TFeO + MgO (2.17~9.18 wt%) content, relatively low Na2O and CaO content. Trace elements and rare earth elements show relatively rich enrichment of compatible elements and light rare earth elements, similar to those of typical upper crust elements. The normalized distribution of rare earth element chondrite shows that the rare earth elements have obvious right-tilt property, and have obvious Eu negative anomaly and weak Ce negative anomaly, similar to PASS and upper crust. The geochemical characteristics of sedimentary rocks combined with the zircon geochronology and Hf isotope characteristics in the study area indicate that the provenance is mainly from the upper crust of southern part of the Cathaysia block, a small amount of basic volcanic rock areas and ancient crust recirculation. The provenance of the study area did not change significantly in Cambrian. The tectonic setting of the Early Paleozoic is a passive continental marginal environment.
%K 寒武纪沉积岩,地球化学,物源区,构造背景,赣南地区
Cambrian Sedimentary Rocks %K Geochemistry %K Provenance %K Tectonic Setting %K Gannan Area %U http://www.hanspub.org/journal/PaperInformation.aspx?PaperID=31099