ABSTRACT

The foraminiferal species in a mudlump from the Mississippi River were recorded and the number of individuals of each species was counted. This population was compared to living foraminifera to determine the paleoenvironment in which the mud accumulated. A Chi-square test was performed to determine whether conclusions based only on the number of species present in a sample are similar to conclusions that take into account the number of individuals found for each species.

The foraminifera in a sample of mudlump material were identified and used to determine the depth, salinity, and temperature of the paleoenvironment. Comparison with living species indicated that water conditions were middle shelf, open marine type; the depth was between 50 and 125 meters; the salinity was between 35 and 38 parts per thousand; and the temperature ranged between 17 and 25 degrees Centigrade.

Interpretations were based on the frequency distributions relative to each of the environmental parameters. The frequency distributions of the numbers of individuals compared favorably with those of the number of species. Chi-square analysis confirmed that no significant differences existed between the distributions. This result verifies that conclusions based on either of the frequency distributions are similar.