长江川江段现代沉积物的重矿物组合特征  

Heavy Mineral Assemblages in Modern Sediments of the Chuanjiang River

作　　者：邵磊[1] 李长安[1,2] 张玉芬[3] 康春国[4] 杨建[1] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]中国地质大学生物地质与环境地质教育部重点实验室,武汉430074 [3]中国地质大学地球物理与空间信息学院,武汉430074 [4]哈尔滨学院,哈尔滨150086

出　　处：《地质科技情报》2010年第3期49-54,共6页Geological Science and Technology Information

基　　金：国家自然科学基金项目(40771213;40672206);国家重点基础研究发展规划项目(2004CB720204);中国地质调查局地质调查项目(1212010814057)

摘　　要：川江是长江上游物源的主要汇集河段,其重矿物组合特征对长江的形成与演化研究非常重要。通过对金沙江、川江主河段及各支流沉积物进行系统的样品采集和重矿物组合特征分析发现,川江段干流重矿物组合稳定,以赤褐铁矿-磁铁矿-钛铁矿-绿帘石-角闪石-辉石-绿泥石为主。川江段干流与支流在重矿物组合方面存在显著不同,各主要支流的重矿物组合也有明显差异。金沙江、川江段及川江段的主要支流的沉积物重矿物特征与其源区的表壳岩系显示出极好的一致性。通过比较发现,川江段干流重矿物组合主要受金沙江制约,尽管有众多的支流汇入,但并未改变干流的重矿物组合特征,说明宜宾以上的表壳岩系对长江上游的重矿物组合特征具有支配意义。The Chuanjiang River receives most of its sediments from the Upper Yangtze River.Hence,it is important to study the characteristics of heavy mineral assemblages for the origin of the Three Gorges and the evolution of the Yangtze River.Heavy mineral samples were collected from the Jinshajiang River and the main stream and different tributaries of the Chuanjiang River.Analyses were made for the characteristics of heavy mineral assemblages of sediments from these areas.The result shows that heavy mineral assemblages of the main stream are stable and mainly includes hematite-limonite-magnetite-ilmenite-epidote-chlorite-garnet.In contrast,heavy mineral assemblages of the tributaries are obviously different from those of the main stream.Besides,heavy minerals assemblages of the main tributaries and the Jinshajiang River differ from each other.Barite is the characteristic heavy mineral of the Jinshajiang River.In order to clarify the relationship between the Chuanjiang River and the Jinshajiang River,heavy mineral assemblages of Chuanjiang River was compared with that of the Jinshajiang River.It shows that the heavy mineral assemblages of the two rivers are very similar to each other.Based on this we conclude that the heavy mineral assemblages of the former are restricted by the latter and has not been changed by the afflux of the tributaries.This illustrates that the supracrustal rocks above Yibin dominate the heavy mineral assemblages of the upper Yangtze River.

关 键 词：川江段 重矿物 特征分析 

分 类 号：P57[天文地球—矿物学]