Paleozoic-early Jurassic tectonic evolution of North China Craton and its adjacent orogenic belts

The Early Paleozoic tectonic stage of the North China Craton (NCC) began around 520 Ma, when Gondwana assembled in its peak tectonism. The Middle Cambrian deposition occurred on older strata or basement rocks along margins of the NCC. Then the marine environment expansion and its extensive invasion led to the late Middle Cambrian marine deposition, with the Mantou Formation and afterward strata distributed throughout the NCC. New research results of the Bainaimiao arc belt to the north of northern NCC indicate that the arc was active from 520 Ma and lasted until 420 Ma, which could extend to east Siping in Northeast China. Along the southern edge of the NCC the northward subduction of the Shangdan Ocean took place during ca. 514-420 Ma. Marine regression occurred later than the Majiagou phase in Middle Ordovician in most parts of the NCC. Recently some Devonian plutons and volcanic rocks were recognized in northern NCC. The Late Carboniferous sedimentary sequence with the 'G' layer of bauxites at its bottom overlies the Middle Ordovician limestone in unconformity. The bauxites were derived mainly from ashes produced by volcanism mainly in the Inner Mongolia Paleo-uplift during Paleozoic period, particularly in latest Early Carboniferous to Early Permian when the northern margin of the NCC evolved as an Andean-style active continental margin. The sequence is mainly clastic formations composed of coal-bearing sandstones and siltstones interlayered with marine limestone and volcanic ash, which demonstrates that they formed in a terrestrial-marine transitional or terrestrial environment with volcanic arc settings. After late Early Permian a terrestrial environment was dominant in the NCC. In southern NCC and the Qinling Orogenic Belt spreading of the Mianlue Ocean between the South China Craton and the South Qinling Block was sustained in Late Paleozoic, and the northward subduction-accretion of the Mianlue Ocean was active in Late Paleozoic. In Triassic the collision between the South China Craton and the South Qinling Block along the Mianlue suture resulted in intense shortening and uplift of Qinling Orogenic Belt and HP/UHP metamorphism documented in Hong'an-Dabie-Sulu terranes. Meanwhile in northern NCC significant changes in tectonic deformation and magmatism occurred in Late Triassic. In the Panshan region, Xiabancheng region and Niuyingzhi region of northern NCC, intense regional folding and thrusting took place around 210 Ma or slightly later, suggesting that the NCC entered into its initial decratonization stage.