来自同位素年龄鉴定的证据指出，绿岩带在年龄上彼此变化相当大。
Evidence from isotopic dating suggests that the greenstone belts vary considerably in age.
本研究共采集岩心样品1003个，发现介形类化石557个，鉴定出15个化石组合带，测得252组碳氧同位素和189组微量元素比值数据。
In this study, 1003 core samples were collected, found 557 fossils of ostracods, identified the 15 fossil assemblage, the measured carbon and oxygen isotopes 252, and 189 trace element ratio data.
燃煤飞灰(以下简称飞灰)作为时间标记物克服了放射性同位素137cs示踪方法不能鉴定大气核爆炸之前的土壤再分布过程这一缺陷。
Using fly ash as a tracer overcomes the limitation that the 137cs tracer method has in explaining the processes of soil redistribution prior to a nuclear explosion in the atmosphere.
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