Isotopic systems and stirring times of the earth's mantle
Isotopic systems and stirring times of the earth's mantle
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DOI：
10.1016/0012-821x(95)00184-e
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发表时间：
1995-12
影响因子：
5.3
通讯作者：
C. Allègre;E. Lewin
中科院分区：
文献类型：
--
作者：
C. Allègre;E. Lewin
我们已经开发了一个简单的模型，它描述了同位素和化学非均质性的油藏经历分异，输入和对流的演化。我们证明，父母的女儿等时图，如地幔材料，相关线的斜率给出了近似搅拌时间，定义为特征时间的均匀化由于对流。在铅-铅同位素图（207 Pb 204 Pb与206 Pb 204 Pb）的情况下，相关性的斜率对应于搅拌时间的两倍数量级的年龄。我们将整个上地幔的搅拌时间限制在0.9Ga左右，而MORB源储层的搅拌时间则限制在220 Ma左右。
We have developed a simple model which describes the evolution of isotopic and chemical heterogeneities of radiogenic systems in a reservoir undergoing differentiation, input and convection. We demonstrate that for parent-daughter isochron diagrams, such as those for mantle materials, the slope of the correlation line gives the approximate stirring time, defined as the characteristic time of homogenisation due to convection. In the case of the lead-lead isotopic diagram (207Pb204Pb vs.206Pb204Pb ) the slope of the correlation corresponds to an age of the order of twice the stirring time. We then constrain the stirring time of the whole upper mantle at around 0.9 Ga, and that for the MORB source reservoir alone at about 220 Ma.