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| 用87Sr/86Sr研究海平面变化与全球对比问题 | |
| 引用本文： | 李荣西,魏家庸,杨卫东,郭庆军.用87Sr/86Sr研究海平面变化与全球对比问题[J].地球科学进展,2000,15(6):729-733. |
| 作者姓名： | 李荣西 魏家庸 杨卫东 郭庆军 |
| 作者单位： | 1. 中国科学院地球化学研究所矿床地球化学开放研究实验室,贵州,贵阳,550002;西安工程学院,陕西,西安,710054 2. 贵州省区域地质调查研究院,贵州,贵阳,550005 3. 中国科学院地球化学研究所矿床地球化学开放研究实验室,贵州,贵阳,550002 |
| 基金项目： | 国家自然科学基金，中国博士后科学基金，贵州省自然科学基金，49773179，1999/10，99-3091，，， |
| 摘 要： | 综述了近年来国际上在Sr同位素研究应用方面的新成果,着重讨论了如何应用海相沉积岩(物)87Sr/86Sr比值来研究海平面变化和全球对比问题。综合分析表明,海水Sr同位素组成受Sr的来源控制,海水87Sr/86Sr比值随时间变化与海平面变化有内在的联系,高频旋回(时限约2.0Ma)的87Sr/86Sr变化与三级海平面变化相对应。研究认为牙形石是分析Sr同位素组成最理想的样品,用之建立的87Sr/86Sr变化曲线最具全球对比意义。与国外相比,我国在这方面研究成果较少,但从地质条件分析,我国独有的一些地质记录,在古海平面变化和全球对比研究中占据着不可缺少或不可代替的地位,其中扬子地块西南缘二叠—三叠纪界限附近的87Sr/86Sr变化曲线,可以弥补国外一些学者建立的自显生宙以来全球海水87Sr/86Sr变化曲线在该时段存在的“断层”现象。 |
| 关 键 词： | 锶同位素 海平面变化 全球对比 牙形石 |
| 收稿时间： | 1999-08-30 |
| 修稿时间： | 2000-05-08 |
VARIATIONS OF RATIO OF 87Sr/86Sr IN SEAWATER WITH TIME:IMPLICATIONS FOR SEA LEVEL CHANGES AND GLOBAL CORRELATION |
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| LI Rong-xi,WEI Jia-yong,YAN Wei-dong,GUO Qing-jun.VARIATIONS OF RATIO OF 87Sr/86Sr IN SEAWATER WITH TIME:IMPLICATIONS FOR SEA LEVEL CHANGES AND GLOBAL CORRELATION[J].Advance in Earth Sciences,2000,15(6):729-733. | |
| Authors: | LI Rong-xi WEI Jia-yong YAN Wei-dong GUO Qing-jun |
| Institution: | 1.Geochemistry Institute,CAS,Guiyang550002,China;2.Xi'an Engineering University,Xi'an 710054,China;3.Guizhou Bureau of Geology and Mineral Resources,Guiyang550005,China |
| Abstract: | Strontium(Sr) is one of the most sensitive indicators to seawater. It has been widely exploited both in terms of its concentration and particularly in its isotope, which has been used to investigating ancient sea level fluctuations. Appreciable progresses have been achieved in recent years, but problems still remained with the seawater87Sr/86Sr curve construction for the purpose of global correlation. It is shown that the variations of87Sr/86Sr throughout the Phanerozoic are related to the sea level changes. High-frequence(2.0 Ma) fluctuations in seawater87Sr/86Sr consistent with third-order sequence. These changes are controlled by Sr sources of the seawater. There are two main Sr sources, one is“the continental Sr”with a high87Sr/86Sr, which is input to seawater by flux, the other one is“the oceanic Sr”with a low87Sr/86Sr, which is got into seawater directly by hydrothermal circulation through seafloor. Conodont is the idea sample for the studies because of its precise stratigraphic age and high Sr concentrations as well as relatively resistant to digenetic alternation. The87Sr/86Sr curve of seawater constructed by using conodont is the best standard for global correlation. China possesses some unique geological records, such as the continuous sedimentation at the Permian/Triassic boundary, which is very helpful to supplement the gap in the87Sr/86Sr curve constructed for seawater from Permian to Jurassic by R. B. Koepnicket al(1998) on the basis of Burkeet al(1982). |
| Keywords: | Strontium isotope Sea level change Global correlation Conodont |
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