石英ESR法在河流沉积物源示踪中的探讨及应用  

A Study on ESR Signal Intensity and CI Provenance-Tracing of Quartz and Its Potential Application to River System Sediments

作　　者：魏传义[1,2] 刘春茹[2] 李长安[1,3] 李文朋[2] 张玉芬[4] 李建平[2] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]中国地震局地质研究所地震动力学国家重点实验室,北京100029 [3]中国地质大学生物地质与环境地质国家重点实验室,武汉430074 [4]中国地质大学地球物理与空间信息学院,武汉430074

出　　处：《地球与环境》2017年第2期157-163,共7页Earth and Environment

基　　金：国家自然科学基金项目(41671011;41372178);中国地震局地质研究所地震动力学国家重点实验室2016年度自主课题(LED2016A08)

摘　　要：使用石英ESR法示踪河流沉积物源是一种新方法和新理论的探索。本文从拟解决的科学问题出发,在着重分析石英ESR信号强度和CI值物源示踪理论基础之上,讨论了该方法在亚洲现代沙尘沉降物源示踪和地质历史时期风尘堆积物源示踪研究中的有效性,结合ESR测年可覆盖整个第四纪时期的特性,认为石英ESR法不仅可以为物源示踪提供良好的年代框架约束,而且还可以较好的反映地质历史时期沉积物质来源在不同时空尺度上的变化特征。随后,通过对指导思想、研究思路以及长江流域不同河段和主要支流的地质地貌背景、岩石类型分布、水系组合特征以及"源-汇"系统之间物质剥蚀-堆积过程的可通达性等方面的综合论述与分析,讨论了石英ESR法在河流沉积物源示踪上的有效性及其在研究长江流域水系发育历史和沉积演化过程中的可行性。Previous studies show that accuracy of the fluvial sediments provenance results is hampered by the disadvantage of provenance or dating approaches, so that the river provenance study is waiting for new research methods. This paper discussed a new exploration of theory and method coupled ESR signal intensity with crystallinity of quartz（CI） in tracing the provenance of fluvial sediments. Our study further compiled the effective provenance applications in Asian dust during modern and historical periods, according to provenance tracing theoretical analysis of ESR signal intensity and CI and advantage of the ESR dating throughout the whole Quaternary period. Geomorpholo- gy and hydrological characteristics between the source and sink, as well as the geological background of the Yangtze River were also investigated in this study. ESR provenance tracing method can not only establish a chronostratigraphic framework, but also ascertain spatial and seasonal discrepancy of the historical sediments. Based on the above analysis, we suggest that this method may be appropriate for tracing the sediment source and/or understanding erosion-transportation processes within the Yangtze River Basin.

关 键 词：石英 电子自旋共振(ESR) 石英结晶度(CI) 河流演化 物源示踪 

分 类 号：P597[天文地球—地球化学]