Benthic Foraminifera Morphology: A Tool for Paleoenvironmental and Paleowater Depth Interpretations

GARY, ANTHONY C., University of South Carolina, Columbia, SC

Quantitative analysis of morphologic variation within recent benthic foraminiferal species from the northwestern Gulf of Mexico reveals changes in some populations that parallel environmental gradients (i.e., morphoclines). Such relationships likely reflect the influence of particular environmental variables on the morphology of the individual during its development and can be used as an indicator of paleoenvironment and paleowater depth. The specimens studied were taken from the top 5 cm of sediment of box cores collected on the shelf and slope. The two-dimensional outline of each specimen was converted to a Fourier series in closed form, and patterns in the data and their correlation to physical parameters were explored using SAWVEC and correlation analysis. Of the specimens studied seven exhibited a correlation between morphology and environment: Bolivina albatrossi, Bolivina subaenariensis mexicana, Bolivina subspinescens, Bulimina marginata, Cibicidoides pachyderma, Sphaeroidina bulloides, and Uvigerina peregrina. Paleowater depth and paleoenvironmental interpretations based on environmentally induced morphologic changes within species complement techniques presently being used based on species distributions by utilizing some different species and providing greater precision in the upper- and middle-bathyal zones.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)