LATE CRETACEOUS STRATIGRAPHY AND ICHNOLOGY IN NW COLOMBIA:
PALEOENVIRONMENTAL, PALEOECOLOGICAL AND PALEOGEOGRAPHIC
IMPLICATIONS
The Cretaceous in Colombia was a time marked by a complexity of geological processes (e.g. accretion of oceanic terranes, arc magmatism and eustatic sea level fluctuations), which has difficult understanding the geological evolution of the NW margin of South America. Cretaceous marine sedimentary rocks are common in western Colombia, extending along the Western Cordillera to the San Jacinto Fold Belt (SJFB) in the Caribbean. In the SJFB, the Cansona Formation is composed of chert, siliceous mudstones, micritic limestones, and tuffs of Santonian Maastrichtian age, deposited in deep or shallow marine environments according to authors. Similar units to Cansona Formation have been recorded in the north of the Western Cordillera. One of them is called the Nutibara Member of the Penderisco Formation, which is primarily composed of chert, micritic limestones, and siliceous mudstones, associated to slope marine environments.
In recent field campaigns carried out by the author in the mentioned units, abundant and well preserved trace fossils were identified. These trace fossils have not been previously studied. Taking into account the usefulness of the trace fossils as a proxy in paleoenvironmental research, we will conduct a detailed stratigraphic and ichnological analysis in some sections of the Cansona Formation (San Carlos and Purgatorio quarries, and the Cansona Hill) and the Nutibara Member of the Penderisco Formation (Uramita-Dabeiba and Frontino-Nutibara sections). This work aims to obtain a detailed paleoenvironmental and paleoecological interpretation that will contribute to a better understanding of the paleoceanographic and paleogeographic conditions at the NW South America margin during the Late Cretaceous.