EFFECTS ON THE TECTONOTHERMAL MODELING OF EXTENSIONAL BASINS
He Lijuan\ Xiong Liangping\ Wang Jiyang (Institute of Geology, Chinese Academy of Sciences, Beijing 100029)
The thermal history of sedimentary basin relates closely to its tectonic history. The tectonothermal modeling of extensional basins is to study the thermal and subsidence histories in the process of basin extension. The evolution history is mainly controlled by the characteristics of lithosphere extension. In this paper, some effects on the tectonothermal modeling are discussed. 1) Multi phases stretch: The inheritance of extension embodies not only the structure, but also the temperature field. The unsteady temperature field of earlier extension stage will have great effects on the evolution history of later stage. The thermal history and present thermal state of basin is controlled by comprehensive effects of multi phases stretch. 2) Lithosphere base: It influences the tectonothermal history of basin greatly. Its selection and variation is worth further study. 3) Stretch mode: Different stretch modes will give different evolution processes. The selection of stretch mode is very important to reconstruct properly the process of evolution. 4) Lateral nonuniformity: The lateral nonuniformity of extension could cause lateral difference of thermal gradient and lateral heat transfer within the basin. In this case, the tectonothermal history of adjacent blocks will influence each other. In one word, tectonothermal model should be developed in the direction of multi phases, non instantaneousnesness and nonuniformity .