元古，读音yuán gǔ，汉语词汇，上古的意思。
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.
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.
东部地形复杂，坡度较陡，岛屿众多，海底是褶皱的元古代沉积岩和太古代结晶岩。
East complex terrain, a steep slope, numerous islands, is the fold of the seabed Proterozoic sedimentary rocks and too ancient crystalline rock.
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