Paleobiological Implications of Living Benthic Foraminiferal Distributions in Northern Gulf of Mexico Sediments

Anthony C. Gary, Nancy Healy-Williams

Twenty-one box cores from the shelf and slope of the northern Gulf of Mexico were sequentially sampled to a sediment depth of 20 cm and stained with Rose Bengal. The water depth of the box-core samples ranged from 52 to 4,510 m. The greater than 63 µm fraction of each sedimentary interval was examined for the presence of stained (living) benthic foraminifera. The down-core distribution of living specimens are compared between a deltaic and a nondeltaic environment. Forty-four species are epifaunal and 30 species infaunal. However, distinct habitat differences exist between species of the same genus. Contrasting the deltaic and nondeltaic environments, specimens from the deltaic samples occur in greater abundance and to greater sediment depths (up to 20 cm) than those from the nondeltaic environment, which occur to a maximum sediment depth of only 3 cm. These results demonstrate that considerable caution should be used and generalizations avoided with regard to the microhabitat preferences of fossil benthic foraminifera.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.