Edad de la formación vijes en el pozo v3a, oligoceno del piedemonte oriental de la cordillera occidental, departamento del valle del cauca, colombia

Outcrops of the Vijes Formation are restricted to the Vijes and Mulaló areas, which are located in the northwestern part of the Valle del Cauca Basin. Based on its micro-paleontological content (palynomorphs and forams) an Oligocene age has been assigned for this Marine Unit for long time considered as an Eocene to Miocene Formation. The Vijes Formation, has a thickness close to 180 m. It is made up of limestones, dirty sandstones and calcareous siltstones, that allow to sub-divide it in four Units which from bottom to top are: 1-) Polimictic conglomerates with local intercalation of plant bearing siltstones (0 and 20 m). 2-) Reef limestones, with abundant bivalve-remains, calcareous algae, strong foraminifers, gastropods, colonial and solitary corals. 3-) Dark siltstones and fine-grained sandstones that have yielded abundant microfossils assemblages which include some crustacean remains. 4-) Quartz-sandstones, with plant remains. Twelve core samples from the Vijes Formation, in the V3-A borehole were analyzed using palynological and foram methods. These samples provided good microfossil assemblages, which belong to the Cicatricosisporites dorogensis pollen zone and to the planktonic foram biozones Cassigerinella chipolensis/Pseudohastigerina micra, Globigerina ampliapertura and Globorotalia opima opima. The boundary between these biozons corresponds to the limit between the Rupelian and Chattian (30 Ma), and is related to the principal sea level drop during the Tertiary. The Vijes Formation is resting unconformable on the Diabasic Group of Turonian-Santonian age and underlies Quaternary sediments. This hiatus indicates that in the Valle del Cauca Basin the Western Cordillera has undergone deformation, emersion and erosion periods between the Late Cretaceous and the Late Eocene.  The area where strata from the Vijes Formation were deposited, can be considered as a sea gate that allowed the entrance of Oligocene waters coming from the West to the present Cauca Valley area. This fact could explain the presence of marine horizons within Guachinte (La Leona Horizon) and Ferreira Formations (San Francisco Horizon).

• Autores: Dueñas, Hernando; Navarrete, Rosa Esther; Mojica, Jairo; Pardo, Mauricio; Camargo, Roger
• Tipo de recurso: Article of journal
• Fecha de publicación: 2000
• Institución: Universidad Nacional de Colombia
• Repositorio: Universidad Nacional de Colombia
• Idioma: spa
• OAI Identifier: oai:repositorio.unal.edu.co:unal/42065
• Acceso en línea: https://repositorio.unal.edu.co/handle/unal/42065; http://bdigital.unal.edu.co/32162/
• Palabra clave: Geología; Ciencias de la tierra; Geociencias; Bioestratigrafía; Formación Vijes; Oligoceno; Palinomorfos; foraminiferos; ambiente arrecifal; Geología; Biostratigraphy; Vijes Formation; Oligocene; Cauca Valley Province; Colombia; Palynomorphs; forams and reef- environment
• Rights: openAccess
• License: Atribución-NoComercial 4.0 Internacional