--> Eastern Cordillera of Colombia: Jurassic to Neogene Crustal Evolution, by D. H. Roeder and R. L. Chamberlain; #90986 (1994).
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Abstract: Eastern Cordillera of Colombia: Jurassic to Neogene Previous HitCrustalNext Hit Evolution

Dietrich H. Roeder, Randy L. Chamberlain

The Eastern Cordillera of Colombia is a Dahlstromian east-vergent fold-thrust belt of Neogene age emplaced on an unbroken 2 to 4.5° west-dipping slab of cratonic lithosphere. This is based on GEOSEC-supported analysis of surface geology, basin and burial history, subsurface Previous HitstructureNext Hit of the Oriente foothills, and geodynamic aspects. The belt involves 5 to 10 km upper crust, 3 km of syn-rift fill of an early Atlantic embayment, and 11 km of Cretaceous thermal-sag basin fill. The fold-thrust belt contains 170 km of imbricate thrust overlap at its front and at higher thrusts, and 60 km of west-vergent backthrusting at its west slope. Its crest is affected by incipient plateau collapse. The Oriente fore land load flexure suggests more than 100 km, and is consistent with 170 plus 60 k , of intracontinental subduction. Andean Previous HitcrustalNext Hit data and Pacific plate tectonics data suggest a Miocene-age change from low-dip subduction to recent steep-dip subduction. Therefore a polyphase history in which foreland upthrusts redeform the Dahlstromian belt is unlikely, but upper-Previous HitcrustalTop detachment prior to Dahlstromian thrusting is possible.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994