Archean Cratons

China includes several blocks of ancient continental crust known as cratons. These include the North China craton, South China craton (including the Cathaysia and Yangtze blocks), and the Tarim block. Parts of northeastern and southern China in these cratons are well known for Late Proterozoic-age sed imentary deposits that host some of the world's most spectacular early animal fossils. One of the best studied sequences is the Doushantuo Formation of phos-phatic sedimentary rocks exposed in south China's Guizhou Province, dated to be 580-600 million years old. The Sinian fauna is therefore older than the well-known Ediacaran metazoan fauna, and is currently the oldest-known assemblage of multicellular animal fossils on the Earth. The macrofossil assemblages are associated with prokaryotic and eukaryotic microfossils, and display remarkably well-preserved cellular and tissue structures and even remnants of organic material known as kerogen. Many of the fossils are unusual acritarchs, organic walled fossils with peripheral processes such as spines, hairs, and flagellum, which cannot be confidently placed into any living plant or animal group classification. Scientists are currently debating the origin of some of the fossils, whether they may be metazoan embryos, multicellular algae, filamentous bacteria, acritarchs, or phytoplankton.

Continue reading here: North China Craton and Tarim Block

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