Replacement can be a marvelously precise process, so that details of shell ornamentation, tree rings in wood, and delicate structures in bone are accurately preserved.

替换可能是一个令人惊叹的精确过程，因此贝壳纹饰的细节，树木的年轮和骨的微妙结构都被准确地保存。

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Ten thousand years of tree rings show that the carbon-14 level rises and falls about every 420 years.

一万年的树木年轮显示，碳14水平大约每420年上升和下降一次。

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For the time before records began, we have only "proxy records" reconstructed largely from tree rings and ice cores, supplemented by a few incomplete written accounts.

在开始有记录之前，我们只有主要根据年轮和冰芯重建的“代理记录”，还有一些不完整的书面记录作为补充。

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Data going back further than a century or two is derived from "proxy" indicators such as tree-rings and stalactites which, again, are subject to large errors.

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To find out how warm the earth was before that, climatologists have had to resort to indirect methods, such as measuring tree-rings, or counting the different isotopes of oxygen in layers of polar ice.

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Fusa Miyake discovered Carbon-14 and Beryllium-10 traces in tree rings from the era, which point to a gamma ray burst from a celestial body other than the Sun.

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