Tectonic Style and Oil and Gas Accumulation in the Moldavian Platform

Pene Constantin¹, Negulescu Rodica², and Coltoi Octavian^1
1University of Bucharest, Bucharest, Romania
²Prospectiuni SA, Bucharest, Romania

The Moldavian Platform represents the western part of the East European Platform. Seismic profiles, well logs, cores as well as geological cross sections and maps show that during Alpine orogeny, the western part of the platform was gradually underthrusted by the Eastern Carpathian Orogene. This structural evolution imprinted a monoclinal character of the deposits and they dip westward beneath the Carpathian Foredeep (Molasse) and Eastern Carpathian Flysch. The compressional tectonic regime accompanied by slowly strike-slip movements and interrupted by short moments of extension imprinted the main tectonic style of the Moldavian Platform. It is dominated by a fault network with two predominantly directions. A first system of major faults, almost parallel with the Eastern Carpathian Orogene is of NNW-SSE orientation (Paltinoasa Fault, West Paltinoasa Fault, and Siret Fault). The second system consists of small cross faults (E-W oriented) and it generated more tectonic block alignments that follow the longitudinal fault trace. The older deposits than the Upper Sarmatian ones plunge step by step beneath Eastern Carpathians along major faults. The tectonic blocks on every step folded and generated gently anticlines and faulted monoclines. The intense compressional regime and the high subsidence rate of the Sarmatian deposits favored the formation of the lithostratigrafic traps. The gas and gas-condensate are reservoired in Albian, Badenian and Sarmatian sandstones and marls and anhydrites seal them. The study of the tectonic evolution of the Moldavian Platform suggests new prospective areas for the gas and gas-condensate in the pre-Badenian deposits.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece