A Micro-Organic and Ecologic Investigation of Recent Sediments from Two Gulf Coast Cores: ABSTRACT

Abstract

The relationship between the recoverable microorganic remains and the depositional environment of Recent sediments in two cores from the Gulf Coast area was studied. One continuous 3 3/4-foot core from Matagorda Delta was sectioned and studied every three inches in order to detect minute vertical variations. The second core from Galveston Bay was 63 feet long, but not continuous. Nine samples were studied, each sample representing an interval of two to three feet of sediment. The detailed analysis of the Matagorda core indicates three distinct depositional environments within the few feet of core. In descending order, these are marine, less marine, and more marine. In the 63 feet of Galveston core, analysis of samples gave an over-all picture of depositional environments, in descending order: marine, less marine, more marine, and continental. Therefore, the environments detected in the very detailed analysis of the continuous samples represent minor fluctuations in what shows up as a single environment in the longer core. The calcium carbonate content decreases with depth End_Page 347------------------------------ in both cores, suggesting some diagenetic effects after burial of the sediments and organic remains, rather than a direct relationship with foraminiferal and ostracodal populations. Foraminifera, Ostracoda, spores, and pollen are present in both cores. In addition, the core from Matagorda Delta contains hystrichosphaerids and the core from Galveston Bay contains diatoms. End_of_Article - Last_Page 348------------