Abstract: Structural Trend Analysis by Axial Surface Mapping of the Northeastern Thrust Front of the Eastern Cordillera, Colombia
Freddy Corredor
Three different structural styles have been recognized at the northernmost area of the eastern thrust front of the Eastern Cordillera of Colombia, using the structural trend analysis by axial surface mapping technique (Shaw et al, 1994): (1) Thick skin thrust faults involving the Precambrian basement with vergence and direction of tectonic transport to SE, represented by the Guaicaramo thrust system; (2) Thin skin thrust faults with vergence to SE, represented by the Eastern thrust fault system. Two detachment levels were interpreted for this system--one at the bottom of the Lower Cretaceous sequence and the other at the bottom of the Upper Tertiary shales of the San Fernando Formation. A value of crustal shortening of 49% (21 km) has been calculated for this specific str ctural style; (3) Lateral strike slip faults with NE-SW and NW-SE predominant trends. This structural style is affecting and controlling the changes in the direction of the eastern thrust front in this area.
The uplift of the eastern thrust front of the Eastern Cordillera of Colombia began during the Early Miocene or Middle Miocene and is currently active.
AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela