Isotopes within rocks of different ages show that the gold in Earth's mantle came after the planet formed, delivered by meteorites. Karen Hopkin reports.

凯伦·霍普金（Karen Hopkin）在报告中指出：不同年代岩石中的同位素揭示了地幔中的金矿是在地球形成之后，由陨石带到地球所形成的。

There's gold in them thar hills—and we may have meteorites to thank. Because it appears that a rain of meteors nearly 4 billion years ago peppered the Earth’s exterior with precious metals. So says a study in the journal Nature. [Matthias Willbold, Tim Elliott and Stephen Moorbath, "The tungsten isotopic composition of the Earth’s mantle before the terminal bombardment"]

“石头的价值在于能不断地产出黄金”——我们真要感谢陨石了。这是因为一场大概是40亿年前的流星雨使贵金属布满了地球表层。一项自然杂志的研究如是说。[引自马赛厄斯·威尔伯德，蒂姆·艾略特与史蒂芬·摩尔巴斯《最终爆炸前的地幔中钨的同位素化合物 》]

When Earth was forming, molten iron sank to its center, creating the planet's core. That iron carried with it a slew of iron-loving metals, including gold and platinum. In fact, the Earth’s core is packed with enough precious metals to cover the entire planet four meters deep.

当地球处于形成阶段，熔融的铁沉入地心，形成地核。铁下沉的同时也带走了大量亲铁金属，包括金和铂。实际上，地心所富含的贵金属足够将整个地球表面覆盖上四米的厚度。

But not all that glitters is down at the planet's center. Today there's enough gold in the Earth's rocky shell to please prospectors—and to puzzle planetary scientists: why is that gold not down in the core, too?

但并不是所有“财宝”都沉入了地心。如今，地壳里依然藏着足够数量的贵金属可以满足勘探者的胃口，也疑惑着行星科学家们：为什么这些金没有沉入地球深处呢？

The answer, it seems, is that it wasn't even on the Earth until after the core formed. Isotope concentrations in rock samples of different ages indicate that the composition of the Earth's mantle changed after the planet was blasted with meteors 3.9 billion years ago. That bombardment coated our home with a thin veneer of riches. Which means that the gold in them thar hills is older than the hills. —Karen Hopkin

答案似乎是这样的：这些贵金属在地心形成之前并不存在于地球上。不同年代岩石样本中的同位素浓度显示：地幔化合物成分在39亿年前地球被陨石撞击后发生改变。而那场爆炸使地表镶嵌了薄薄的一层贵金属。可谓让石头赋有价值的黄金可比石头的年龄大的多啊。

There's gold in them thar hills. 出处不详，可能出北美淘金热时期。此句的正常写法是：There's gold in them there hills 粗俗的美国口语中，喜欢在them后加一个副词性代词以加重语气——thar（there）。类似的还有this（here），there（here），that（there）和those（there）。

关于最后一句的翻译。含有贵金属的陨石爆炸后散落地表，由于地质作用形成贵金属矿，所以我说，金子比山的年岁大。