辽北地区南华系地球化学特征及其对沉积环境的制约  

Geochemical characteristics of Nanhua System in northern Liaoning Province and its restriction on depositional environment

作　　者：张林 曹煜昊 阮昕[1] 徐耸 卢崇海 ZHANG Lin;CAO Yuhao;RUAN Xin;XU Song;LU Chonghai(Liaoning Institute of Mineral Exploration,Shenyang 110031,Liaoning,China;School of Resources Northeastern University,Shenyang 110819,Liaoning,China)

机构地区：[1]辽宁省矿产勘查院有限责任公司,辽宁沈阳110031 [2]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《矿产勘查》2021年第9期1861-1870,共10页Mineral Exploration

基　　金：辽宁省地质矿产勘查局科研项目(辽地科[2016]04号)资助。

摘　　要：辽北地区卢崇海等重新划分的新元古代南华系冰期地层缺少系统的的地球化学研究,本次对该研究区域新划的南华系岩石地层碎屑沉积岩地球化学分析表明,样品的成分变异指数(ICV)值均略大于1.0,代表活动大陆边缘首次沉积的产物,其碎屑岩的成熟度较低。化学蚀变指数(CIA)值及Sr/Cu值表明,殷屯组处于寒冷、干燥的环境。陈千户组、汎河组地层处于干燥-寒冷与温暖-湿润之间变换的环境。南华系殷屯组、陈千户组和汎河组地层中Al_(2)O_(3)/TiO_(2)、TFe_(2)O_(3)+MgO、Ti/Zr、La/Co值及南华系物源判别图显示,辽北地区殷屯组、陈千户组和汎河组沉积物源的原始物质主要来自上地壳的长英质物源,混入少量长英质、基性岩混合物源。通过与不同构造环境下砂岩地球化学参数对比及碎屑岩构造判别图分析表明,辽北铁岭地区南华系殷屯组、陈千户组和汎河组沉积岩构造环境为活动大陆边缘。The Neoproterozoic Nanhua glacial strata redivided by Lu Chonghai and others in northern Liaoning Province lack systematic geochemical study.The geochemical studies of the Neoproterozoic Nanhua glacial strata newly divided by Lu Chonghai in northern Liaoning Province show that the Index of Composition Variation(ICV)of the samples are all greater than 1,indicating poor maturity,which may be the product of the first deposition in active continental margin.The values of Chemical Index of Alteration(CIA)and Sr/Cu indicate that the Yintun formation is in a cold and dry environment.The Chenqianhu formation and the Fanhe formation are in a changing environment between dry,cold,warm and humid.According to the contents of TFe2O3+MgO,Ti/Zr,La/Co,and source discriminate plot for the Nanhua System,the original materials of the Yintun formation,Chenqianhu formation and Fanhe formation in northern Liaoning mainly come from felsic provenance of the upper crust,mixed with a small amount of felsic and basic rock mixture source.According to the comparison of geochemical parameters of sandstones under different tectonic environments and major element function plot of tectonic setting analysis,it is shown that the sedimentary rock tectonic environment of Yintun formation,Chenqianhu formation and Fanhe formation in Tieling area of Northern Liaoning Province is an active continental margin.

关 键 词：地球化学 物源区 构造环境 南华系 

分 类 号：P631[天文地球—地质矿产勘探]