100Ma来海水的锶同位素组成演化及主要控制因素  

Sr-isotope Composition and Evolvement in Sea Water Over Past 100Ma and Control Factors

作　　者：黄成刚[1] 黄思静[1] 吴素娟[1] 陈启林[2] 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [2]中国石油勘探开发研究院西北分院,甘肃兰州730020

出　　处：《地球科学与环境学报》2006年第2期19-24,共6页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(40272059)

摘　　要：讨论了100Ma以来海水锶同位素比值的变化趋势及控制因素。100～40Ma期间。海水锶同位素比值有多次升降，总体上变化幅度较小；40Ma以来，海水锶同位素比值显著增加，并呈现出单凋上升的总体特征。100Ma以来海水锶同位素的变化主要可能与星外物体对地球的撞击作用；全球海平面变化及洋中脊扩张速度的改变；喜马拉雅-青藏高原的隆升；玄武岩喷发和冰川作用因素有关。在各种因素中，喜马拉雅-青藏高原的隆升对40Ma以来海水锶同位素演化具有最重要的控制作用。喜马拉雅-青藏高原的隆升可能始于40Ma左右，隆升速度最快的时期在20～15Ma。The Sr-isotope composition and evolvement in sea water since 100 Ma and the controlling factors are discussed. The sea water 87 Sr/86 Sr ratios in the period of 40- 100 Ma have some fluctuations with smaller extent. The sea water 87 Sr/86 Sr ratios have increased rapidly and monotonously since 40 million years, The following factors controlled the Sr isotope composition and evolvement in sea water since 100 Mat the possible impact of extraterrestrial object; the global sea-level change and the spread rate of the mid-oceanic ridge; the uplift of Himalaya-Tibet; the eruption of major continental flood bassalts and glaciations. Among of above factors, the uplift of Himalaya-Tibet plays an important role in the evolution of seawater 87 Sr/86 Sr ratios for the last 40 Ma. The starting time for the Himalayan-Tibet uplift should be at 40 Ma BP, and the most rapid period of the uplift took place during 20-15 Ma.

关 键 词：海水锶同位素组成 100 Ma来 地质事件 青藏高原隆升 全球海平面变化 

分 类 号：P736.4[天文地球—海洋地质]