DISTRIBUTION AND TAXONOMY OF MODERN BENTHIC FORAMINIFERA OF THE WESTERN SUNDA SHELF (SOUTH CHINA SEA) OFF PENINSULAR MALAYSIA

• Main Author: Martin, Samuel Q.
• Other Authors: Culver, Stephen J., Geological Sciences
• Format: Master Thesis
• Language: English
• Published: East Carolina University 2016
• Subjects: Sunda Shelf; South China Sea; taxonomy; Foraminifera > Malaysia > Geographical distribution; Foraminifera > Malaysia > Classification; Benthos; Sunda; Planktonic foraminifera
• Online Access: http://hdl.handle.net/10342/5896

This study investigates, for the first time, the distribution and taxonomy of modern benthic foraminifera from the western Sunda Shelf, southern South China Sea. The uppermost centimeter of 54 surface sediment samples ([greater than] 150 [mu]m) from nearshore (8 m) to inner shelf (60 m) water depths yielded 125 species. Five sample groups (CGT1–5) are recognized by cluster analysis of the total (live + dead) foraminiferal relative abundance data. Discriminant analysis and ANOVA both revealed that the five groups are statistically distinguishable at the 95% confidence level. The distribution of groups is related to variations in depth (as a proxy for several environmental factors) and substrate grain-size. This relationship is confirmed by canonical correspondence analysis. CGT1, located closest to shore (8–14 m water depth), has a high diversity assemblage (49 species) and is characterized by Amphistegina radiata and Amphistegina lessonii. CGT1 occurs in medium to coarse quartz sand substrates likely derived from the nearby Terengganu River with the exception of a single station (TR1-S2). This site is characterized by a mud substrate, the taxa Ammobaculites exiguus, Millettiana millettii, Planorbulina acervalis, and Rosulina globularis, and an unusually high relative abundance (3%) of planktonic foraminifera. CGT2 (21–22 m) has a lower diversity assemblage (33 species) and is strongly dominated by A. radiata and A. lessonii, often with tests infilled by the authigenic mineral berthierine. CGT2 occurs in gravelly quartz sand substrates. CGT3 (32–41 m) occurs in shelly muddy quartz sand substrates, has a high diversity assemblage (46 species), and is characterized by Assilina ammonoides, Discorbinella bertheloti, and Asterorotalia milletti. Like CGT2, berthierine-rich internal molds of Amphistegina tests are common. CGT4 (44–59 m) occurs in mud substrates and is characterized by Heterolepa dutemplei and A. milletti; the nearshore taxa A. radiata and A. lessonii do not occur in this group. CGT4 has the ...