Tonian Tectonic‐Strata Regions and their Geological Significance in China

Abstract

AbstractThe continent of China developed through the coalescence of three major cratons (North China, Tarim and Yangtze) and continental micro‐blocks through the processes of oceanic crust disappearance and acceretionary‐collision of continental crusts. The strata of the Chinese continental landmass are subdivided into 12 tectonic‐strata regions. Based on the composition of geological features among the three main cratons, continental micro‐blocks and other major global cratons, their affinities can be preliminarily deduced during the Tonian period, using evidence from sedimentary successions, paleobiogeography, tectonic and magmatic events. The Yangtze and Tarim cratons show that they have close affinities during the assembly‐dispersal milestone of the Rodinia Supercontinent. The sedimentary record and magmatic age populations in the blocks suggest that there was a widespread, intensive magmatic event that resulted from a subduction process during ∼1000–820 Ma, related to continental rifting around the Yangtze and Tarim cratons. However, they differ greatly from the North China Craton. The continental micro‐blocks in the Panthalassic Ocean could have some missing connection with the North China Craton that persisted until the Middle‐Late Devonian. In contrast, the Alxa Block showed a strong affinity with the Tarim Craton. The revised Tonian paleogeography of the Rodinia Supercontinent is a good demonstration of how to show the relationship between the main cratons and the continental micro‐blocks.