地质矿物风化作用下形成锶同位素在沉积学领域的应用  

Application of strontium isotope formed by weathering of geological minerals in Sedimentology

作　　者：郭耀庚 GUO Yao-geng(Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学,四川成都610059

出　　处：《世界有色金属》2020年第22期178-179,共2页World Nonferrous Metals

摘　　要：锶同位素地层学由瑞典地质学家Wickman于1948年提出,其基本原理是:锶在海水中的残留时间(≈10^(6)a)远远大于海水的混合时间(≈10^(3)a),使得海水^(87)Sr/^(86)Sr值为时间的函数。海水^(87)Sr/^(86)Sr值主要受壳源锶和幔源锶2个来源锶的影响,壳源锶主要由陆地岩石的风化作用提供,幔源锶主要由洋中脊热液系统提供。全球性的构造运动、风化速率的变化、洋中脊活动、全球海平面升降以及全球灾变性事件等都会影响到壳源锶与幔源锶的供给,从而影响海水^(87)Sr/^(86)Sr值的变化。锶同位素曲线^(87)Sr/^(86)Sr值的变化同样也可反映地质历史时期的各类事件。锶同位素在沉积学领域中多用于海相地层定年、研究海平面变化、分析物质来源等。The strontium isotope stratigraphy was proposed by Swedish geologist Wickman in 1948.Its basic principle is that the residual time of strontium in seawater(≈10^(6)a)is much longer than the mixing time of seawater(≈10^(3)a),making the value of ^(87)Sr/^(86)Sr in seawater a function of time.The ^(87)Sr/^(86)Sr value of seawater was mainly affected by the two sources of strontium from shell and mantle,which were mainly provided by the weathering of terrestrial rocks and the mantle-derived strontium from the hydrothermal system of mid-oceanic ridge.Global tectonic movement,change of weathering rate,midocean ridge activity,global sea-level rise and fall,and global disaster and degeneration events will affect the supply of shellderived strontium and mantle derived strontium,thus affecting the change of ^(87)Sr/^(86)Sr value of seawater.The variation of ^(87)Sr/^(86)Sr on the strontium isotope curve can also reflect various events in geological history.Strontium isotopes are widely used in the field of sedimentary science to date Marine strata,study sea level changes,and analyze material sources.

关 键 词：锶同位素 锶同位素地层学 锶同位素应用 海相地层定年 海平面变化 锶同位素曲线 

分 类 号：P597[天文地球—地球化学]