The dated isotope record shows that the fluctuations in global ice volume over the past several hundred thousand years have a pattern: an ice age occurs roughly once every 100,000 years.
同位素年代记录显示,过去几十万年全球冰量的波动有一个模式:冰河期大约每10万年发生一次。
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The team collected 146 samples of rocks from mountainsides and then dated the rocks’ so-called cooling age, which reveals when the rock was exposed by erosion.
And because those artifacts closely resemble others from nearby sites previously carbon-dated to about 9000 B.C., Schmidt and co-workers estimate that Gobekli Tepe's stone structures are the same age.