发现导致玻璃碎片散落全球的行星灾难遗留的神秘陨石坑
Mysterious Crater From Planetary Catastrophe That Scattered Glass Pieces Around Globe Discovered
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2020-01-02 15:38
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火星译客

Almost a million years ago, a large meteorite impacted the Earth, throwing glass pieces known as tektites thousands of kilometres away, to the territories of what are now modern Australia, Southeast Asia, and Antarctica. Now, scientists are finally able to say where the mega-strike happened.

大约一百万年前,一颗巨大的陨石撞击地球,将名为玻陨石的玻璃碎片抛向数千公里外的如今的澳大利亚、东南亚和南极洲地区。现今,科学家们终于能够说出那场宏大的撞击到底发生在哪里。

The site where a large meteorite that hit Earth some 800,000 years ago, scattering small glass pieces thousands of kilometres away, is located where Laos is today, an international team of researchers have concluded, the German news agency DPA reports. According a scientific paper published in the "Proceedings" of the US National Academy of Sciences ("PNAS"), a team led by Kerry Sieh from Singapore's Earth Observatory believes that the impact crater is concealed under a layer of volcanic rock on the Bolaven Plateau in the south of the Southeast Asian country.

据德国DPA通讯社报道,一个国际研究小组得出结论,大约80万年前一颗巨大的陨石撞击地球,将小玻璃碎片散落数千公里外的碰撞地点,就是今天老挝所在的地方。根据发表在美国国家科学院(“PNAS”)“学报”上的一篇科学论文,来自新加坡地球天文台的Kerry Sieh领导的一个研究小组认为,撞击坑隐藏在这个东南亚国家南部博拉文高原的一层火山岩下。

As was discovered earlier, the mega-catastrophe happened around 790,000 years ago. The strike made terrestrial debris melt, hurling the pieces, which later solidified into tektites, over a tenth of the Earth's surface, namely Australia, Southeast Asia, and Antarctica.

正如早先发现的那样,这场大灾难发生在大约79万年前。撞击使陆地碎片融化并将碎片抛出,这些碎片后来凝固成玻陨石,覆盖了地球表面的十分之一,即澳大利亚、东南亚和南极洲地区。

However, where the meteorite hit had remained a mystery, despite intensive searches in the past decades.

然而,尽管在过去的几十年里进行了密集的搜索,但陨石击中的地点仍然是一个谜。

"This suggests that either there was never a crater or that it disappeared - either because of erosion or because of spillage", Sieh wrote.

Sieh写道:“这表明要么从来没有陨石坑,要么它消失了--要么是因为侵蚀,要么是因为泄漏。”

But the large field of volcanically-created basalt rock on the Bolaven plateau has shown several indications that this is the enigmatic site that researchers had been looking for. According to the scientists, some rocks from the plateau geochemically match the scattered tektites. Their analyses suggest that the lava flowed over and near the suspected crater, pouring out after the impact. Gravity anomalies have been detected there, suggesting that there is a 17-by-13-kilometre crater under the surface. There are boulders several kilometres away from the suspected crater that are believed to have been ejected during the impact.

但博拉文高原上火山形成的大片玄武岩已经显示出一些迹象,表明这就是研究人员一直在寻找的神秘地点。根据科学家们的说法,高原上的一些岩石在地质学上与分散的玻璃陨石相匹配。他们的分析表明,熔岩在疑似陨石坑上方和附近流动,在撞击后倾泻而出。他们在那里探测到了重力异常,表明地表下有一个17乘13公里的陨石坑。在距离疑似陨石坑几公里的地方有一些巨石,据信是在撞击过程中喷出的。

Meteor glowing as it enters the Earth's atmosphere. Elements of this image furnished by NASA.

© Fotolia / Vadimsadovski

© Fotolia / Vadimsadovski

However, this collision is not the only catastrophe that Earth experienced around that time, as researchers led by Heidelberg geoscientist Mario Trieloff found out earlier. They determined the exact age of the tektites found around the globe almost four years ago as they were examining both tektites from the Asian-Australian region (which is at the centre of the latest research) but also glass rocks from Canada and Belize in Central America.

然而,正如海德堡地球科学家Mario Trieloff早些时候发现的那样,这次碰撞并不是地球在那个时期经历的唯一灾难。他们确定了近四年前在全球发现的玻陨石的确切年龄,当时他们既检查了来自亚洲-澳大利亚地区(这是最新研究的中心)的玻璃陨石,也检查了来自加拿大和中美洲伯利兹的玻璃岩石。

Their conclusion is that one more space visitor hit the Earth around 790,000 years ago, as the examined glass bodies all originated from the same period. However, the tektites from Belize had a different chemical composition, which indicates that they might have originated from a different impact than the one in Asia.

他们的结论是,大约79万年前,又有一名太空游客撞上了地球,因为被检查的玻璃体都来自同一时期。然而,来自伯利兹的玻陨石具有不同的化学成分,这表明它们可能源自不同与亚洲的另一次撞击。

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