Paleontology of molluscan assemblages from Bangkok clay in Samut Prakan, Central Thailand

Abstract

In the Holocene, 6.3 ka, shallow marine deposits by the Jyoumonn Transgression are commonly found all over the world. In Thailand, the representative strata i.e. Bangkok clay in the central lowland can be correlated with Jyoumoun Transgression. Ban Phraek Sa Sand Pit in Samut Prakan, the study area yield abundant molluscan fossils were reported. But there were very few data on ecological analysis of molluscan fossils from the upper most past of Bangkok clay. In addition, only one ¹⁴C-AMS datum was reported. Accordingly, seven sample blocks of 25X25x40 cm were cut down perpendicular to the bedding plane. Total number of block is 7. Molluscan assemblage primary consist of Pelecypod. Total number of species is 41 and individuals are 700. At the result of paleoecological analysis of molluscan assemblages, Veremolpa-Scapharca Assemblage are recognized. The results of ¹⁴C-AMS analysis for of four molluscan fossils are 1175±28, 1204±28, 1276±29 and 1264±28 years. Whereas two plants yield an age of 3456±30 and 1395±28 years. Reconstructed environment is similar to the first stage of Transgression.