Modeling Paleobathymetric and Relative Sea Level Curves from Palynofacies, Palynomorphs Paleoecology and Lithofacies Analysis

Oscar Yepes, Carlos Jaramillo, and Francisca Oboh

Palynological and lithofacies data from seven stratigraphic sections from the Late Quaternary and Cretaceous of Colombia, and the Late Paleogene of the U.S. Gulf Coast have been used to reconstruct paleobathymetric and relative sea level curves.

Our palynological methodology consists of two major components: a palynofacies analysis and a paleoecological interpretation of dinoflagellates, pollen and spores assemblages. A minimum of 300 organic matter particles are counted in each sample recording their composition, size of longest axis, sorting and level of degradation. A statistical treatment of the recorded data, such as lognormal distribution, cluster and principal component analysis was conducted. Under the assumption of a dominance of allocyclic processes, the clustered samples are ordered according to their organic matter content, which indicate their positions relative to the paleoshoreline.

Dinoflagellates, pollen and spores taxa are clustered according to minimum variance cluster and similarity indexes. The paleoecological meaning of each group is interpreted based on the current literature. When correlating several sections, cluster from every section are compared with each other to obtain palecological associations that mainly reflect a position relative to the shoreline. The final reconstruction of relative paleobathymetric curves is based on the integration of lithofacies, paleoecology and palynofacies data. This technique is useful in Carboniferous to Recent rocks and sediments from continental or marine origen.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California