Recently available vitrinite reflectance data, temperature-depth profiles, and heat flow values have made it possible for us to develop an improved computer model to simulate the subsidence, thermal, and maturation history of the Pannonian basin. This model takes into consideration different rates of extension in the lower and upper lithosphere, heat generation in the crust, the thermal blanketing effect of fast sedimentation, the change in porosity and thermal conductivity in space and time, and both normal and abnormal compaction of sediments. Model parameters are constrained by comparison of predicted and observed subsidence histories, present crustal thicknesses, temperature versus depth profiles, and heat flow values. We conclude that lithospheric stretching, combine with major additional thinning of the subcrustal lithosphere, is adequate to explain the formation and evolution of the Pannonian basin.

Thermal maturation of organic matter was calculated by the use of the Lopatin method. Model results were compared with measured vitrinite reflectance (R₀) in eight master holes that range in depth between 1792 m and 5865 m. This provides an improved relationship between the time-temperature index (TTI) and vitrinite reflectance for 0.25% <= R₀ <= 3%, and for temperatures up to 230 °C. This relationship was then used to reconstruct the maturation history of potential source rocks in the basin. It shows that hydrocarbon generation started at 10 Ma and progressed so rapidly that sedimentary rocks currently below a depth of 4-5 km have completely passed through the oil generation window. The upper 2 to 3 km of the sedimentary rocks are, however, immature ov r the whole Pannonian basin.

Comparison of the known oil and gas fields with the present maturity conditions in the Great Hungarian Plain shows that 49 out of 53 fields are located outside of, and at some distance from, the areas of hydrocarbon generation. Traps are associated mostly with compactional anticlines above basement highs and with positive structures along strike-slip faults. Future prospects may be predicted in deeper zones where hydrocarbons could have accumulated in stratigraphic and unconformity traps and in the fractured basement.

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