Abstract
The distributional patterns of modern benthic foraminifera from the inner shelf of the southern South China Sea, off the east coast of peninsular Malaysia, are documented for the first time. The study area from Tanjung Sedili, Johor in the south to Marang, Terengganu, in the north was selected for a sand-resource study by the Minerals and Geoscience Department, Malaysia in 1993. Twenty-four surface sediment samples from <50 m water depth contained 266 foraminiferal species belonging to 6 orders, 49 families, and 117 genera, including 32 agglutinated, 130 calcareous hyaline, and 104 calcareous porcelaneous species. Two biofacies were distinguished by cluster analysis. Biofacies A was characterized by high relative abundance of Amphistegina papillosa and few other larger benthic foraminiferal (LBF) taxa in sandier sediments. Biofacies B was characterized by Pseudorotalia schroeteriana and other small rotaliids that were found in muddy sediments. The following features of foraminiferal assemblages and sediments reflect the strong fluvial/terrestrial influence on this tropical shelf environment: the overall moderate foraminiferal diversity, dominance of rotaliids over miliolids, overall dominance of smaller foraminiferal assemblages by Elphidium crispum, the limited diversity of LBF, the limited abundance of A. lessonii and the dominance of LBF assemblages by A. papillosa at relatively shallow depths. These features indicate at least intermittently turbid waters with limited light penetration and the dominance of the shelf sediments by siliciclastics, with mean percent carbonates <35%.
