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.

凱倫·霍普金（Karen Hopkin）在報(bào)告中指出：不同年代巖石中的同位素揭示了地幔中的金礦是在地球形成之后，由隕石帶到地球所形成的。

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"]

“石頭的價(jià)值在于能不斷地產(chǎn)出黃金”——我們真要感謝隕石了。這是因?yàn)橐粓龃蟾攀?0億年前的流星雨使貴金屬布滿了地球表層。一項(xiàng)自然雜志的研究如是說。[引自馬賽厄斯·威爾伯德，蒂姆·艾略特與史蒂芬·摩爾巴斯《最終爆炸前的地幔中鎢的同位素化合物 》]

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.

當(dāng)?shù)厍蛱幱谛纬呻A段，熔融的鐵沉入地心，形成地核。鐵下沉的同時(shí)也帶走了大量親鐵金屬，包括金和鉑。實(shí)際上，地心所富含的貴金屬足夠?qū)⒄麄€(gè)地球表面覆蓋上四米的厚度。

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“財(cái)寶”都沉入了地心。如今，地殼里依然藏著足夠數(shù)量的貴金屬可以滿足勘探者的胃口，也疑惑著行星科學(xué)家們：為什么這些金沒有沉入地球深處呢？

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

答案似乎是這樣的：這些貴金屬在地心形成之前并不存在于地球上。不同年代巖石樣本中的同位素濃度顯示：地幔化合物成分在39億年前地球被隕石撞擊后發(fā)生改變。而那場爆炸使地表鑲嵌了薄薄的一層貴金屬。可謂讓石頭賦有價(jià)值的黃金可比石頭的年齡大的多啊。

There's gold in them thar hills. 出處不詳，可能出北美淘金熱時(shí)期。此句的正常寫法是：There's gold in them there hills 粗俗的美國口語中，喜歡在them后加一個(gè)副詞性代詞以加重語氣——thar（there）。類似的還有this（here），there（here），that（there）和those（there）。

關(guān)于最后一句的翻譯。含有貴金屬的隕石爆炸后散落地表，由于地質(zhì)作用形成貴金屬礦，所以我說，金子比山的年歲大。