随着钻井活动导致地下水位下降，下层土壤正变得密实，就像失水的海绵一样。

As Wells are drilled and the water table drops, the underlying soil compacts, much like a dried-out sponge.

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研究者们拼凑了包括头骨，手掌，脚掌，上臂，腿和骨盆在内的125块骨骼碎片，并采集挖掘处上层和下层的火山土壤层测定年代。

Researchers have pieced together 125 fragments of bone - including much of her skull, hands, feet, arms, legs and pelvis - which were dated using the volcanic layers of soil above and below the find.

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—洛斯阿拉莫斯国家实验室的地质学者沃德·盖布·瑞尔采集化石挖掘地点上层和下层的火山土壤层分析测定其年代在440万年前。

Geologist Giday WoldeGabriel of Los Alamos National Laboratory was able to use volcanic layers above and below the fossil to date it to 4.4 million years ago.

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