太古代,是地质发展史中最古老的时期,该时期所形成的地层称为太古宇。该时期延续时间长达15亿年,是地球演化史中具有明确地质记录的最初阶段。由于年代久远,太古代的保存下来的地质纪录非常破碎、零散。但是,太古代又是地球演化的关键时期,地球的岩石圈、水圈、大气圈和生命的形成都发生在这一重要而又漫长的时期,大约39亿年前,地球形成最初的永久地壳,至35亿年前大气圈、海水开始形成。
n. Archeozoic ; archaeozoic
misc. Archaeozoic era
鄂东北大别杂岩中的表壳岩系属于晚太古代层状变质岩系。
The supracrustal sequences in the dabie complex in northeastern hubei belongs to a late archean stratified metamorphic sequences.
如此低的硫酸盐浓度,表示太古代大气中的氧气极为稀薄。
Such low levels of sulfate indicate that the archean atmosphere was virtually devoid of oxygen.
地球的历史可分为四个时期——依次经历冥古代、太古代、元古代和显生宙。
The history of Earth is divided into four eons - starting with the earliest, these are the Hadean, Archean, Proterozoic, and Phanerozoic.
We have people inventing them, but even the ones that are invented aren't very helpful, because it's awfully hard to know how they did what they did.
有人试图还原古代战争,但是得出的结果并没有太大的意义,因为我们对此实在是知之甚少
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