Bulletin of the Geological Society of Malaysia, Volume 33, Nov. 1993, pp. 119-127
Institute of Geophysics, Chinese Academy of Sciences, Tatun Road, Beijing 100101, P.R. China
Abstract: The paleogeothermal history inversion method is studied in this paper. The thermal model implies variation of basal heat flow with time, and thermal conductivity with sediment porosity and composition. The thermal evolution as a nonlinear function can be represented by segments of linear functions in which each segment reflects a tectonic stage. The technique of inversion including the Simplex and Monte Carlo methods have been used for the calculation of geothermal evolution and the comparison of the calculated and observed vitrinite reflectances.
The application of nonlinear inversion method has been illustrated in the research of geothermal history for the northern part of South China Sea. The results including tectonic and geothermal histories suggest that most of the oil-bearing rocks in the area are mature and overmature and at least two or three extensions have occurred since the Later Mesozoic period.