Sedimentology and hydrocarbon habitat of the submarine-fan deposits of the Central Carpathian Paleogene Basin (NE Slovakia)

The Central Carparhian Paleogene Basin accommodates a subsiding area of the destructive plate-margin. The basin history comprises marginal faulting and alluvial fan accumulation (E-2); transgressive onlap by shoreface sediments and carbonate platform deposits (E-2); glacio-eustatic regression induced by cooling (Terminal Eocene Event); forced regression, tectonic subsidence and growth-fault accumulation of basin-floor and slope fans (E-3): decelerating subsidence. aggredation and sea-level rising during the mud-rich deposition (O-1); high-magnitude drop in sea-level (Mid-Oligocene Event), retroarc backstep of depocenters and lowstand accumulation of sand-rich fans and suprafans (O-2-M-1): subduction-related shortening and basin inversion along the northern margins affected by backthrusting and transpressional deformation (O-2-M-1). The basin-till sequence has poor (TOC less than or equal to 0.5%) to fair (TOC < 1.0%) quality of source rocks. Maturity of OM ranges from initial to relic stage of HC generation. Paleogene rock-extracts display a good correlation with scarce trapped oils. The presence of solid bitumens and HC-rich fluid inclusions indicates overpressure conditions during HC generation and migration. Potential HC reservoirs can be expected in porous lithologies (scarp breccias), in basement highs and traps related to backthrusting, fault-propagation folding and strike-slip tectonics. (C) 2001 Elsevier Science Ltd. All rights reserved.