扬子地块西南部晚元古代——三叠纪沉积地球化学演化  

Sedimentary Geochemical Evolution from the Upper Proterozoic to the Triassic in the Southwest Yangtze Massif

作　　者：于炳松[1] 裘愉卓[1] 李娟[1] 

机构地区：[1]中国地质大学,中国科学院地球化学研究所矿床地球化学开放室

出　　处：《沉积学报》1997年第4期127-133,共7页Acta Sedimentologica Sinica

基　　金：中国博士后科学基金;中国科学院矿床地球化学开放研究室基金

摘　　要：本文通过对扬子地块西南部自上元古界板溪群到三叠系发育在盆地和下斜坡背景中的泥质岩的系统的无素地球化学研究，首次发现了下寒武统、上泥盆统和上二叠统这三个在元素地球化学性质上明显不同于其它层位的地球化学异常层，从而构成了本区地质历史中三个明显的地球化学旋回。通过地球化学旋回与本区地壳演化和一系列沉积事件之间关系的研究，发现它们之间存在着内在的必然联系，说明沉积地层的地球化学演化是地球发展演化的必然结果和物质表现形式。因此，可通过这些地层的元素地球化学体系来恢复地壳发育和演化历史。Through the systematic study of trace elements and REE geochemistry of mudstones deposited in the basin and lower slope environments from the Upper Proterozoic to the Triassic in the Southwest Yangtze Massif,three geochemical abnormal horizons,Lower Cambrian,Upper Devonian and Upper Permian,were discovered.Because of the alternate occurrence of three geochemical abnormal horizons,three geochemical cycles in geological history were distinguished.The geochemical cycles are corresponding to the geotectonic ones in this area.The geochemical abnormal horizons are corresponding to the pull apart stages of geotectonic cycles and to a series of geological events,such as hydrothermal sedimentary events,anoxic events,extinct events of living things and so on.That so many events occur red in the geochemical abnormal horizons at the same time indicated these geochemical anomalies are the result of earth evolution.They are the products originating in the particular stages of earth evolution.So these geochemical anomalies,conversely,are the effective geochemical tracer to understand the earth,especially the crustal evolution.

关 键 词：沉积地球化学 地壳演化 扬子地块 元素地球化学 

分 类 号：P595[天文地球—地球化学] P512.2[天文地球—地质学]