STRATIGRAPHY OF THE TABLAZO FORMATION, MIDDLE MAGDALENA VALLEY, COLOMBIA

The former type section of the Tablazo Formation of Upper Aptian to Middle Albian was located in the Middle Magdalena Valley Area, Colombia. The type section has been covered by the reservoir of the Hidrosogamoso Dam, therefore our project was to evaluate and document a replacement type section in the area of El Tablazo. The mixed carbonate and clastic sediments were deposited in the shoreface of a shallow marine ocean that once flooded most of central Colombia and was later uplifted to form the Eastern Cordillera.Our study also examined sedimentary petrography to classify the sedimentary facies, to detect microfossils, and to interpret diagenetic alteration. The lower part of the section is mainly a calcareous sandstone, and the upper part is dominated by biomicritic packstone limestone. Microfossils are predominantly calcispheres and benthic foraminfera. Diagenetic fabrics include the replacement of silica by calcite, dissolution seams and micrite recrystallization.