MODELLING STUDY ON THE PROFILE STRUCTURE OF TB LINE IN DONGHAI

In this paper, 147km of TB seismic profile across Qiantang Depression,Xihu Depression till Diaoyudao upfolded belt is interpreted. In view of the characteristics that Donghai continental shelf basin has gone through fault depression-passive continental margin-compression-depression multistages tectonic superimposition since the Paleocene,the models of depression,prOfile equilibrium and fault depression are established. By means of the modelling software package developed by the authors,the original thickness of eachstage strata is calculated and restored,and the subsiding and compacting processes of depression are reproduced. By the method of the combination of equiarea and critial-layer equilibrium,the recOvery of compressive structure between T₄⁰ and T₂⁰ is realized,equilibrium profile is obtained,and shorten range of each bedded plane is caIculated. Based on the situation that growth faulting information inverses plow faulting till in the deep part and by calculation on the displacement fields and movement loci of middle and upper plates during the course of extension,the extended range about 10.4km from Xihu Depression to Diaoyudao upfolded belt in the Paleocene period is obtained-By the connexion and combination Of depressiOn,profile equilibrium and fault depression models,the modelling of fault depression-compression-depressio inversion and superimposition is realized, the subducting and developing history of entire tectonics reappears,and the dynamic results of the modellings are shown by the graphs of certain time intervals.