Structural
Evolution and Coupled Kinematic-Thermal Modeling of the Upper
Magdalena Basin in the Vicinity of the Garzon Massif, Colombia
F. Roure1, J. L. Faure2, B Colletta2, C
Macellari3, and M Osorio4
1 IFP, Rueil-Malmaison, France
2 IFP,
3 Hocol, Bogota, Colombia
4 Hocol,
The Upper Magdalena constitutes an intramountain basin, characterized by
a succession of horsts and grabens inherited from Jurassic rifting episodes.
Post-Jurassic sedimentation records subsequent Cretaceous thermal subsidence and
Paleogene flexural subsidence in the foreland of the Central Cordillera, and
Neogene transpressional reactivation and inversion of the Jurassic grabens
during Andean tectonics, coeval with the thrust emplacement of the Eastern
Cordillera. Surface and subsurface data including regional reflection seismic
profiles and wells have been used here to constrain four structural
sections
across the Suaza Graben, between the Tarqui Horst in the west and the Garzon
west-verging basement overthrust in the east.
Cross
-section balancing techniques
have been used to restore the
sections
in their pre-orogenic configuration, the
later being ultimately used to perform a coupled forward kinematic and petroleum
modelling with Thrustpack. Results of the modelling demonstrate the strong
control of the Garzon basement overthrust on the timing of the petroleum systems
in the underthrust grabens. Surprisingly, the maturity ranks computed along the
two profiles located beneath the Garzon overthrust are slightly less than in
coeval portions of the Suaza Graben which are located farther south and farther
north. Therefore, it is assumed that high conductivity in the autochthonous
basement drives more heat to the source rocks in the vicinity of the Tarqui
Horst, and conversely, high conductivity in the basement allochthon is
responsible for faster cooling of the sediments below the Garzon overthrust.
AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005