Estructura y evolución tectónica del valle medio y superior del magdalena, colombia

Present work concerns with the structure and evolution of the Upper and Middle Magdalena Valley, a geomorphological depression separating the Colombian Central and Eastern Cordilleras. It constitutes a fringe of an orographically continuous lower land but with conspicuous differences in stratigraphy...

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Autores:: Mojica, Jairo
Franco, Ricardo

Tipo de recurso:: Article of journal

Fecha de publicación:: 1990

Institución:: Universidad Nacional de Colombia

Repositorio:: Universidad Nacional de Colombia

Idioma:: spa

Description
Summary:	Present work concerns with the structure and evolution of the Upper and Middle Magdalena Valley, a geomorphological depression separating the Colombian Central and Eastern Cordilleras. It constitutes a fringe of an orographically continuous lower land but with conspicuous differences in stratigraphy and tectonics; its evolution goes back to early mesozoics times and is the result of diverse deformative events, mainly of distensional type during the Mesozoic, compressional during the Cenozoic. The boundary between the Upper (UMV) and the Middle (MMV) Magdalena Valley is to be found in an area, just north of Girardot, and Honda; however, its location depends on the type of arguments used to define it, e.g. presence of major structural elements such as the oblique passing Cambao-Ibagué Fault- System, the narrowing of the valley due to crossing of fold axis along the Guataquí- Piedras line, or the marked differences in the characteristics and ages of the economic basement detected north and southwards of Honda. The UMV shows a dominant compressive structural style, with combined thrusting and folding, that is present on both sides of the valley. Tectonic displacements are directed toward the center of the depression and may reach up to tens of kilometers as result of accumulated movement along several detachement surfaces In soft and non competent units In the sedimentary cover, as those known In the Villeta and Guaduas Groups. These processes have generated diverse Imbricated tectonic fans, some of which are thick-skinned and basement nucleated, other thin-skinned, thus not· affecting the precretaceous fundament. In the MMV compressive tectonics with reverse and/or low angle faulting is restricted to the eastern portion; on the contrary, to the west and near the Central Cordillera the deformation is mainly caused by normal faulting active in different episodes; therefore thinning and pinch outs of the distinct meso and cenozoic formations are common. Accordingly and for oil prospecting purposes, It seems evident that in the UMV and in the eastern half of the MMV expected traps have to be more of structural type, thus contrasting with those combined stratigraphic-tectonic ones observed In the western portion of the MMV.

Estructura y evolución tectónica del valle medio y superior del magdalena, colombia

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