Late Cretaceous to Cenozoic Deformation at North American-Caribbean Plate Boundary in Northern Central America and its Effects on the Origin and Migration of Hydrocarbons
Sanchez, Carlos J.; Mann, Paul; Emmet, Peter A.
The northern part of Central America represents a complex plate boundary zone that has undergone multiple phases of extension and convergence as the transition from Late Cretaceous-earliest Cenozoic collision to Cenozoic transtension influenced faulting and basin formation in the Honduran borderland region. We interpret 9850 km of 2-D seismic tied to 13 wells, structural and potential fields modeling, and 1D and 2-D-subsidence and thermal simulation, to illustrate the effects on collision-strike-slip transition on oil and migration in this shelf, slope and deepwater area. The Cenozoic strike-slip/transtension phase is characterized by growth (syntectonic) and a post-rift extensional period since Oligocene-early Miocene that produced 7-10% of extension calculated on a section normal to the plate boundary. Two types of normal faults are observed: 1) low-angle (30-40°) faults with high displacements (1500-3500 m) and 2) high-angle (50-70°) with smaller displacements (100-500 m). The first type of normal faults are thick-skinned and possibly detached along the base of crust, where the block rotation produced by their listric and ramp-flat geometry controls the formation of small, rift basins. These faults are related to inversion of the previous Upper Cretaceous-early Eocene compressive setting that show 1-2% shortening, suggested by the configuration obtained after restoring the extensional phase, considering the fault dips, ramp-flat fault geometry and associated structures. The second type of normal faults mainly seen deform the Cenozoic section and can be related to the accommodation of regional extension, folding and thermal sag flexure. Because the current vector of the Caribbean plate motion is oblique by ~15° to the North American-Caribbean plate margin, we assume that the main stress direction is directly controlled by left-lateral, strike-slip kinematics. Assuming a linear proportion between plate displacement rate (~14 cm/yr) and the observed fault deformation, the strike-slip component during Cenozoic may have been four times (30-40 %) the dip-slip deformation calculated in our reconstruction. According with the deformation, subsidence and thermal history, a potential Upper cretaceous-Paleocene source rock could have been buried at oil window by the end of the Miocene where the Cenozoic section is thick, controlled by the displacement and length of faults, which would restrict petroleum systems to each basin, especially to the north of the area.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013