What Drives Orogenic Asymmetry in the Northern Andes?: A Case Study from the Apex of the Northern Andean Orocline

We present the results of 59 new apatite fission tracks (AFT), 24 new vitrinite reflectance analysis, and 154 new He thermocronometric analysis from the eastern flank of the C Colombian eastern Cordillera at lat7° N to constrain the roles of plate tectonics, tectonic inheritance, and surface processes in building the Cocuy syntaxis. The Cocuy syntaxis is the region with the highest structural and topographic relief in the eastern Cordillera. The primary factor controlling that is faster tectonism, apparently related to the most important Panama collision at 4 Ma. This push from behind is focused between two resistant plates and escapes toward a weak foreland plate, which is able to flex. However, we document new Pliocene and younger AFT ages in the eastern side of the eastern Cordillera, which are related with focused and faster exhumation in the eastern flank. We suggest that this episode is responsible for the limited advance of the deformation front as basement-involved blocks. In addition, faster denudation causes faster sedimentation rates in the weak foreland plate east of the Cocuy syntaxis. In this case, the thick pile of Neogene synkinematic sediments would have limited thin skin deformation migration.


Información adicional

País:     Estados Unidos

Autor(es):   

Año:     2015

Áreas:     Termocronologia, Tectónica, Estratigrafía, Cuencas sedimentarias

Revista:    Petroleum geology and potential of the Colombian Caribbean Margin: AAPG Memoir 108, p. 547?586.

Editorial:    The American Association of Petroleum Geologists