Precambrian

The Precambrian ( ; pre-Cambrian, or Cryptozoic, sometimes abbreviated pꞒ or PreꞒ) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinized name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.

distinctive layered units of iron-rich sedimentary rock that are almost always of Precambrian age

fragment of crustal material, sutured to the Eurasian Plate during the Cretaceous that forms present-day southern Tibet