Faunas position in the Colombian Cretaceous deposits and their value in their chronological subdivision

Abstract

It is analyzed the chronostratigraphic situation of the Colombian Cretaceous System from two points of view: a) Localization of the faunas with regard to the lithologic units, b) Chronologic value of such faunas. The first aspect is treated taking lithologic series according to six main regions (Upper Magdalena Valley, W of the Sabana of Bogota, E of the Sabana of Bogota, Middle Magdalena Valley, Catatumbo Region, Guajira peninsula) referring them to the faunas witch can be located with accuracy in each one of the Cretacic levels is presented; the value of several “guide fossils” is discussed; and some interpretative aspects of the Cretacic sedimentation is commented. Also the synonymy of different Cretacic fossils witch have been cited until now, is included. Finally, several considerations about the future trend of the stratigraphic studies in Colombia are presented.