| Abstract:From the standpoint of plate tectonics, this paper deals tentatively with the relations among granitoids of different types, their related ore deposits and faults, and discusses the formation, distribution and material sources of granitoids and related ores in the process of large-scale horizontal and lateral movement, such as B-type(oceanic lithosphere)subduction, A-type seduction (continental lithosphere), downgoing decollement or downthrust. Based upon abundant data on the geological structures, different types of granitoids and related ore deposits in East China, the authors emphasize the importance of the intracontinental compression-subduction(A-type subduction) and downgoing decollement which trend NE, NNE, EW and dip inland(i. e．not toward ocean and in parallel with the Benioff zone)in the formation and distribution of granitoids and related ore deposits. With the rising of temperature and pressure during the subduction, the downgoing plate or slabs would have been degassed, dealkalined and desilicified. Thus, the ore-forming and rock-forming materials for the formation of large or superlarge deposits might have been mainly derived from lateral souxces, that is to say, from the descending plate or slabs during intracontinental compression-subduction. The above discussion has led the authors to establish a metallogenic model in relation to the plate tectonism． |
