MESOZOIC DOME-BASIN STRUCTURES IN WESTERN SHANDONG PROVINCE AND ITS BEARING ON TRANSITION OF TECTONIC REGIMES IN EAST ASIA

According to field observation and previous research results, this paper makes a detailed study on fold superposition as well as structural styles and geodynamics in Western Shandong Province. The Mesozoic tectonic deformation in the region can be obviously divided into two groups, i.e. the Indosinian EW-striking open to tight folds and related reverse faults and the Yanshanian NNE- or NS-striking box fold and related propagating thrust fault system. The dome-basin structures in this region are the results of the superposition of the Indosinian and Yanshanian folds and represent the crustal deformation related to a transition of the geodynamic systems. The tectonic blocks of Yangtze, North China and Siberian assembled in Mesozoic, and then the East Asia formed, that resulted in the formation of EW-striking structures. Until the middle and late Mesozoic, the NNE-striking circum-Pacific tectonic belt gradually developed and began to affect the eastern margin of the East Asia Continent, Then happened the transition from the collisional systems of the Paleo-Asian Ocean and Paleo-Tethys tectonic domains to the the subduction system of the Paleo-Pacific Tectonic Domain.