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Earth Evolution
Earth Materials
Earth Evolution
Geological History
Solar System
Archean Proterozoic Early
Late Paleozoic Mesozoic Cenozoic

Archean Beginnings 3800-2500 Ma
The Oldest Rocks from China

The oldest known Early Archean crustal remains in China are found in the North China Craton, represented by the 3804 million years Baijiafen gneiss in the Anshan Complex, and ~3850 million years detrital zircons within the Caozhuang fuchsite quartzite from Eastern Hebei. The Baijiafen gneiss is a metamorphosed trondhjemite - a plagioclase-rich granite. The Caozhuang fuchsite quartzite originally formed from sediments that must have been eroded and transported from the earliest continents and accumulated under water. Studies of these rocks therefore reveal important clues about the conditions on the early surface of our planet.