Mesozoic and Cenozoic tectono-thermal evolution modeling in the Northern South Yellow Sea Basin

The tectono-thermal evolution history is dominated and influenced by deep geodynamic processes. Geodynamic modeling and traditional geothermometer simulation are integrated and applied to reconstruct the tectono-thermal evolution history of the Northern South Yellow Sea Basin during Mesozoic-Cenozoic. The simulation theory, methods, and work flow, which are based on the advanced McKenzie model, are introduced in this paper. The matching method of theoretical and calculated tectonic subsidence, definition of geophysical parameters, calculation of stretching factors and application of simulation results are also discussed. Modeling results indicate that the paleo-heat flow increased since Mesozoic, which is accompanied by intense rifting processes. The paleo-heat flow was likely to reach a maximum value of 80 mW.m(-2) and the paleo-geothermal gradient could go up to 49 degrees C/km during late Cretaceous to Palaeocene. Tectonic subsidence modeling results of single well show the characteristics of multi-stage rifting processes. The paleo-heat flow continuously decreased once the basin evolution turned into the post-rifting stage, and it reduced down to 65 mW.m(-2) at the end of Miocene, which was accordant with present heat flow. The obtained geophysical parameters and modeling results of one-dimensional simulation have been applied in the reconstruction of three-dimensional paleo-geothermal field. The research methods and results are significant for the future study of tectonic evolution, resources evaluation and the petroleum system of the South Yellow Sea Basin.