论文部分内容阅读
一项新发现,在西澳大利亚发现的远古锆石晶体己有43.74亿年历史,这表明它们所在的这个地方的岩石,是迄今为止在地球上已发现的最古老的岩石。这也意味着地球开始形成地壳的时间比以前认为的早得多,地壳是在45亿年前创造地-月系的大规模撞击事件发生后开始形成的。这项研究的第一论文作者、美国威斯康星大学的约翰·维勒教授说:“这个年代比以前测定最古老的(其他岩石)的年代早3亿年,它仅比岩浆海的出现晚大约1亿年。此时地球开始形成原始大陆地壳,从化学成分的角度而言,它与地幔存在很大不同。
A new finding shows that the ancient zircon crystals found in Western Australia have a history of 4.374 billion years, indicating that the rock they are in is the oldest rock discovered on Earth so far. This also means that the Earth started to form crust much earlier than previously thought and that the crust began to form after the massive crescent moon collision, which was created 4.5 billion years ago. Professor John Vail, of the University of Wisconsin, USA, author of the first paper in this study, said: ”This era was 300 million years earlier than the oldest (other rocks) 100 million years ago, when the Earth began to form the pristine continental crust, which is quite different from the mantle from the chemical point of view.