Palynological Recognition of a Maximum Flooding Surface
Carlos Jaramillo
In order to investigate the palynological response to a maximum flooding event, three Cretaceous sections in the Upper Magdalena Valley and a Paleogene section in the Llanos foothills, Colombia, were studied. Three of them, of Albian, Santonian, and Oligocene ages, are located in a proximal position related to the basin. The fourth section, of Aptian age, is located in a distal position.
In the proximal sections, a Maximum Flooding Surface is recognized based on a
minor decrease in coaly, herbaceous, and woody material, the appearance of
amorphous organic matter and the increase in abundance of dinoflagellate
species. In the distal section, a Maximum Flooding Surface is represented by the
increase of highly degraded amorphous organic matter and a decrease in the
diversity of dinoflagellates and sporomorphs. Therefore, the response of the
palynological record to a maximum flooding event is strongly related to the
position in the basin and the magnitude
of the flooding event. These Maximum
Flooding Surfaces were corroborated with lithostratigraphic and sedimentologic
data.
The palynological record is highly sensitive to the influence and magnitude
of marine incursions during maximum flooding events. This increases the
potential use of palynology for chronostratigraphic correlations and sequence
stratigraphic analysis.
AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995