Organic geochemical and palaeobotanical reconstruction of a late-Holocene archaeological settlement in coastal eastern India

Abstract

Integration of palaeobotanical (spores, pollen, phytoliths and non-pollen palynomorphs) and organic geochemical proxies, such as stable isotopes of organic carbon (δ13C) and n-alkanes, for studying the evolution and palaeoenvironmental conditions of an archaeological site are rare in India. The evolution of a protohistoric-historic site at Erenda, situated in the eastern coastal region of India, has been studied by using multiple palaeobotanical and organic geochemical proxies assisted with AMS radiocarbon dates. The excavated site lies above Late Pleistocene–Early Holocene Sijua Formation. The absence of anthropogenic evidence in the Sijua Formation likely indicates inhabitable conditions in nearshore/estuarine marshy conditions. The earliest human settlements at the excavation site begin during the first millennium BCE after the initiation of habitable conditions along the coast. The presence of fungal spores and the dominance of C4 phytolith morphotypes indicate prevailing warm and humid climatic conditions and proximity to a freshwater body. The δ13C signature and n-alkane composition indicate the use of C4 grass for the construction of the mud and clay-built huts. The settlers most likely used to consume wild or domestic variety of rice, as evidenced by the presence of bilobate scooped morphotypes. The site was partly abandoned, covered with C3 and C4 vegetation and used as a dumping ground after 663 ± 92 BCE. This implies that people continued to live in the area but possibly moved to a nearby site while using the excavated site as refuse.