地质年代测定
- 网络Geological dating;geological age determination
地质年代测定-
作为地质年代测定的基础是史泰侬（Stenon）于17世纪提出的三原则，即：叠加、连续性和原始水平性。
Stratigraphy , the basis of geological dating was founded in the ⅹⅶ century on the three well known principles assumed by Stenon : superposition , continuity , original horizontality .
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地质年代测定通过放射性同位素衰变来测定地质年代放射性碳14测定年龄法
Measurement of geologic time , as through isotopic radioactive decay . radiocarbon 14 dating method
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通常使用的地质年代测定法还未给出结果，这意味着各种可能性都不能排除：纳莱迪人可能生活在远至250万年前，或者另一种极端情况下，他们生活在数万年前。
The usual geological dating techniques have not yet given a result , leaving open the possibility that Homo naledi might have lived as long as 2.5m years ago , or at the other extreme , tens of thousands of years ago .