Abstract: Sedimentology and Hydrocarbon Habitat of the Submarine-fan Deposits of the Levoca Basin (Centrocarpathian Paleogene, Slovakia)
SOTAK, JAN*, JULIA KOTULOVA, PAVEL PITONAK, JAN SPISIAK, JULIUS MAGYAR, RUDOLF RUDINEC
Levoca Basin belongs
to the forearc system of the Central Carpathian Paleogene. The basin history
consists of: Upper Eocene - initial tectonic subsidence with high accumulation
rate of "synrift" deposits (up to 3500 m of the Sambron Beds); subsiding
system gained an asymmetric configuration due to trenchward tilting and
peripheral antithetic faulting (Poprad Depression); Lower Oligocene - post-rift
relaxation with landward deepening and shifting of basin axis (underfilled
basin); Upper Oligocene - flexural loading under high amount of the deep
sea fan deposits, which enlarged the total subsidence up to 6 km of burial
depth; Lower Miocene - subduction-related shortening (NE-SW), which led
to inversion and uplift; the northern side of the basin was attached by
fold-and-thrust tectonics and transpressional deformation. The Paleogene
basin sequence has poor- to fair-quality of source rocks (TOC greater than
or equal to 0.5%). Maturity of OM ranges from initial stage of HCs generation
(central zone) up to relict stage of HCs generation (Sambron zone). Distribution
of n-alkanes gives evidence about predominance of terrigenous OM or mixture
of marine/terrestrial OM. Paleogene rock extracts display a good correlation
with scarce tapered
oils. Oil generation in the basinal deposits is also
noticeable from the presence of solid bitumens and HC-rich fluid inclusions.
Both of them point to overpressure conditions during HC generation and
migration. Potential HC traps can be expected in porous sedimentary members
(scarp breccias), in basement highs and structural environs related to
wrench tectonics.
AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria