VON LUNEN, ERIC, MALCOLM LIGHT, and
PAUL R. KNOX
Bureau of Economic Geology, The University of
Texas at Austin, Austin TX
Abstract: Fault
Patterns and Compartmentalization
in the Badenian Sequence, Matzen Field, Vienna Basin, Austria
The evolution of the Vienna Basin involves
a continuum of tectonic activity from foreland imbrication through Miocene
extrusionary wedge or pull-apart phases closely associated with depositional
sediment influxes. Detailed examination of a 3-D seismic in the Matzen
field and recent research (supported by OMV) suggested that a variety of
fault
styles typical of pull-apart bas n tectonics are interwoven into
a complex pattern. The principal
fault
patterns expected are built upon
a sinistral strike-slip tectonic framework. An extensional trailing imbricate
fault
fan is observed in the Bockfliess area. The Matzen field area exhibits
at various reservoir levels a divergent strike-slip EW
fault
trend cross-cut
repetitively by NNE duplex
fault
geometry. The sinistral strikeslip pattern
exhibits anastomosing
fault
traces at the 16th Tortonian (Badenian), which
evolves vertically into a classic "negative flower structure" at the 7th
Tortonian reservoir level. The Schonkirchen field area is underlain by
a sinistral strike-slip
fault
exhibiting a restraining bend geometry at
the deeper Badenian intervals with a minor horst
fault
block evolving at
shallower reservoir intervals, e.g., 9th and 8th Tortonian, into a "positive
flower structure." Both the Prottes and Schonkirchen areas are dissected
by strike-slip duplexes, interconnecting the major sinistral
fault
trends.
Duplex faults in the area exhibit a mature deformation, which is believed
to be NNE to N Riedal shears rotated into intermediate-angle S-shaped
fault
patterns and flexures. The duplex shears fail again along the dominate
Riedal shear axis. The duplex
fault
pattern is apparently repetitive in
~3-km intervals through the region, as predicted by other authors. These
complex
fault
patterns subdivide the various Badenian reservoir levels
into a series of rhomblike compartments in which both juxtaposition and
clay smearing within
fault
planes may play a critical role in trap seals.
AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas