Messinian Stratigraphic Architectures in the Lacustrine Pannonian Basin, Hungary - Insights from Computer Simulations

Istvan Csato¹, Christopher Kendall², and Phil Moore^2
1Geology, Collin College, Plano, TX
²Geology, University of South Carolina, Columbia, SC

A prominent unconformity in the Messinian (late Miocene) stratigraphic record of the lacustrine Pannonian Basin, Hungary, was found based on seismic and well log interpretations. This surface divides the entire late Miocene-Pliocene basin fill into a second-order highstand progradational-aggradational and a retrogradational unit. The stratal architectural patterns formed in the Messinian vary significantly along the paleo-margins of the lake. Our study introduces quantitative stratigraphic simulations to analyze the role of subsidence/uplift, sediment supply and lake level changes in the origin of the unconformity and the various architectural patterns that evolved in response to the Messinian events.

The results of the numerical simulations are as follows: (1) A lake level fall occurred in the Messinian that was accompanied and followed by a tectonic inversion in several parts of the basin. The simulations show quantitatively that the rate of tectonic subsidence and/or uplift varied in space and time, consequently, the size of the relative lake level fall and the resulting stratal patterns varied significantly across the basin as well. (2) The age of the unconformity determined originally based on paleomagnetic and palynologic data, has been tuned by our simulations. The unconformity constitutes a regional surface allowing regional correlations between the Paratethyan and Mediterranean regions. (3) Combined simulations and seismic interpretations of stratal architecture have led to the formulation of a basin fill model and identification of four straigraphic architectural patterns in relation with the Messinian events. (4) Forced regressive and lowstand systems tract sediments form a significant series of potential stratigraphic traps for hydrocarbons above the Messinian unconformity.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas