ABSTRACT

A total of 168 benthonic foraminifera are noted from five wells in Cameron and Calcasieu Parishes with the intention of interpreting the paleoecology and taxonomy of the Upper Oligocene in age Marginulina zone. Sixteen undescribed benthonic species or morphotypes of previously described species are present.

Well cuttings from the five wells were analyzed at 30 foot intervals. The study wells are oriented in a north-east-southwest transect approximately paralleling the paleo-coast line.

Paleoecological interpretations were made by analyzing nonspecific (species diversity; planktonic:benthonic ratio; etc.) and specific (morphological variation; species predominance; etc.) faunal characteristics. These quantitative and qualitative faunal characteristics indicate that deposition of the Marginulina sediments occurred at a minimum depth indicative of present day outer neritic environments. Deposition may have occurred at greater depths because nonspecific and specific faunal characteristics are only indicative of upper depth limits. The taxonomic study was fundamental to the paleoecologic analysis.