前寒武纪是自地球诞生到6亿年前的这段时间。尽管早在30多亿年前生物就已经出现,但其进化却长期停滞在很低级的阶段,主要是是些低等的菌藻类植物,它们留下的化石说明的情况不多,而且保存这些化石的岩层又太多经过不同程度的变质,更使得地球的早期历史不易被了解,所以才被划入“隐生宙”。
n. Precambrian
misc. Precambrian period
... prairie中纬度草原;温带草原(北美) Pre-Cambrian period前寒武纪 precipitation降水 ...
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Qinling Group is one of the most characteristic Precambrian metamorphic rock series occurred innorth Qinling. The studies of its forming age and metamorphism are quite helpful to therealization of Precambrian geological evolution of the Qinling Orogen.
秦岭岩群是北秦岭最为重要的前寒武纪变质岩系,其形成时代、变质作用特点的研究也是认识秦岭造山带前寒武纪地质演化规律的重要基础。
参考来源 - 秦岭造山带东部新元古代热—构造事件及其地质意义·2,447,543篇论文数据,部分数据来源于NoteExpress
尽管伊迪卡拉是以澳大利亚的一处地名而命名,但伊迪卡拉沉积层却遍及世界各地,并且可追溯到前寒武纪时代。
Although named after a site in Australia, the Ediacaran formation is worldwide in distribution and dates to Precambrian times.
因此,前寒武纪的动物肯定曾经生活在这么深的地方。
Precambrian animals must therefore have lived at such depths.
前三个时期合起来持续了40亿年,合称为前寒武纪(隐生宙)。
The first three eons, which together lasted nearly 4 billion years, are together known as the Precambrian.
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