Chronostratigraphy and correlation of the Pliocene and Quaternary of Colombia

Abstract

Abstract Names for the chronostratigraphic units of the Pliocene and Quaternary of Colombia are defined and formalized based on studies of outcrops and deep bore holes in the area of the high plain of Bogota. Chronostratigraphic, biostratigraphic and lithostratigraphic sequences have been correlated as far as possible. A tentative correlation with the marine oxygen isotope stratigraphy is indicated. Pliocene chronostratigraphic units are provisionally characterized by abundance/first appearance in the pollen record of specific floral elements: Mauritia zone (Tequendamian: ca. 5.5-4.2 Ma), Hedyosmum zone (Facatativanian: ca. 4.2-3.5 Ma), Myrica zone (Sisganian: ca. 3.5-3.1 Ma), Borreria zone (Chocontanian: ca. 3.1-2.7 Ma and Engativanian: ca. 2.7-2.4/2.2 Ma), although precise boundaries cannot yet be established. The Engativanian is a transitional phase, characterized by a continuous temperature decrease in successive cold episodes, and may include the latest part of the Pliocene and the earliest part of the Quaternary. Quaternary chronostratigraphic units are precisely limited by levels of pronounced climatic change; these boundaries are near to the first appearance/abundance of Juglans-Plantago (Funzanian: ca. 2.4/2.2-1.0 Ma), Alnus (Fuchanian: ca. 1000-660 ka and Cotanian: ca. 660-335 ka), and Quercus (Subanian: ca. 335-128 ka, Bacatanian: ca. 128-73 ka, Fuquenian: ca. 73-10 ka, and the Holocene). The relationship with the officially defined position of the base of the Quaternary, at ca. 1.80 Ma, is shown. The last glaciation in Colombia is named the Cocuy glaciation.