BASIC FEATURES AND FORMATION MECHANISM OF PARANEOCATHAYSIAN EXTENSIONAL BASINS SYSTEM

There develop a series of dextral transtesoinal fault basins (graben and half-graben) trending NNE since the late Mesozoic (Cretaceous period) in the continental margin of East China and West Pacific Ocean. These basins were arranged as zigzag pattern in the plane view. Under these fault-basins develop upper mantle-uplifting and basement detachments of the same trend. Some times expressed as metamorphic core complex and big low angle extensional detachments. The regional tectonic stress field has been in horizontal extension of NW-SE direction during post-orogenic period since the late Yanshannian stage. It is continental margin expanding caused by the de-rooting of lithosphere (since the late Cretaceous) and the effect of the collision between India and Eurasia plates (since the end of Late Cretaceous and Early Tertiary period).