A study on the vertical distribution of marsh foraminifera from the Sunderbans, India

Abstract

The Sunderban delta is the largest delta in the world, fed by the Ganga and the Brahmaputra rivers. Geologically, the area results from extensive fluvio-marine deposits of these two mighty rivers at the junction of the terrestrial and the marine realms. Foraminifer, a marine protozoan, is abundantly found in the epipelagic and benthic regions of most marine environments. These unicellular organisms are excellent tools for studying palaeoecology, biostratigraphy, and palaeoenvironments. Two short cores have been studied from the Sunderban regions. A total of seventeen different species have been identified, including both calcareous and agglutinated forms. The dominant taxa are Ammonia tepida, Cribroelphdium poeynum, Haplophragmoides wilberti and Quinqueloculina seminulum. The studied area has low diversity assemblages with a dominance of calcareous forms. Epifaunal forms decrease in number as we move down the core sections.