Abstract: Geometric Delineation of the Colombia Amazon Basins
Ceron, John - Ecopetrol
The Amazon Basin in Colombia comprises the entire jungle covered region south of the Guaviare River with more than 100000 km2 in extension. This geographic- driven definition has been used in most geologic texts, and just recently it has been recognized that gravity, magnetics and magnetotelluric data can provide a valuable interpretation of the basin geometry and main structural elements within the Amazon region.
It is suggested on this work that interpreted basement highs delineate different geologic provinces characterized by individual structural styles: 1) The Florencia and Yari highs, separating the well known Putumayo basin from the Caguan sub basin, and this one from the Chiribiquete - Paleozoic filled sub basin, respectively, where dominantly South-North tectonics Prevails, 2) The Guyana platform with its south western extension south of the Apaporis river, denominated here Caqueta platform, where dominantly Southwest-Northeast structural lineaments can be interpreted; south of this platform several shallow sub basins can be delineated, probably representing the westernmost expression of the Solimões, Brazilian basin, and 3) The central extension of the Guyana Platform, which roughly follows the direction of the Guaviare River at latitude 3N, which serves as the natural divide between the Llanos basins at the North from the Amazon basins. Encompassed between the named platforms it is interpreted an extensional basin, with notorious Northwest-Southeast structural lineaments, the Vaupes sub basin, which is postulated here as an interior Rift system predominantly filled with Paleozoic and Tertiary sediments, but with high probabilities for presence of Mesozoic deposits.
AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil