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