Subdivision and Identification of Sedimentary Tectonic Facies

Sedimentary tectonic facies reveals different types of sedimentary basins and their sequences, distribution and comprehensive combination formed in a tectonic setting of a specific tectonic site in each evolutionary stage during the formation and evolution of a continental block, an ocean or a continental margin (active or passive), which is an integrated product of dynamic processes of divergence, convergence, collision and rotation-shear of continental lithosphere plates as well. It has the function of revealing the formation and evolution of continental blocks and orogenic systems (belts). In order to systematically analyze the complicated process of continental accretion since Neoproterozoic in Mainland China in the perspective of sedimentary tectonic facies and sedimentary basins based on characteristics of formation and evolution in Mainland China, this paper puts forward a set of classification scheme and briefly introduces identification markers of sedimentary tectonic facies (types of sedimentary basins). The scheme can be divided into 4 levels (facies series, macrofacies, facies and subfacies): the first level is continental block (including land block) and orogenic system facies series. Thereinto, continental block can be divided into macrofacies and facies on the basis of tectonic paleogeographic site and regional tectonic stress field. The orogenic system is comprised of arc-basin systems, accretional zone and opposite zone, with huge mountains accompanied by complex lithologic composition, fold and fault. In fact, it is the outcome of arc accretion, arc-arc collision, arc-continent collision, continent-continent collision, and inter-continent subduction in the process of conversion between continent and ocean, under the extensive act of horizontal movement of lithosphere plate. The accretional zone is the product of soft collision controlled by arc-arc and arc-continental collision, which spreads across the ocean-continent transformation accretion zone in continental margin. In contrast, the opposite zone is the outcome of hard collision formed by continent-continent collision. Down to next level, we can divide sedimentary tectonic basins into oceanic basin, forearc bsin, interarc basin, backarc basin, residue sea, peripheral foreland basin, backarc foreland basin, and so on, according to a series of tectonic paleogeographical environment and construction generated by the progress of ocean-continent transformation.