The paleoenvironment of Mahasthangarh (Bangladesh) during the Pre-Modern Period.

If the Geological Survey of Bangladesh has been very active for more than 40 years, the principal missions of the organization are linked to the management of mineral resources and other climatic problems like the rising of sea level, scarcity of drinking water, etc. There exist few research projects on the paleoenvironment connecting archaeologists and geomorphologists even if the trend is changing. For Mahasthangarh, the archaeological mission did not explore this matter much since the pioneering work conducted by Christine Jacqueminet and Jean-Paul Bravard in the 1990’s.

Since February 2022, the Mahasthangarh mission includes a paleoenvironment component. This new project was motivated by a specific archaeological an environmental context. Mahasthangarh is an important ancient fortified city founded around the 4^th centuries BC. The site was the capital of Pundravardhana province, in Northern Bengal, before being gradually abandoned from the 14^th century AD on. Mahasthangarh is located on the eastern margin of the Barind Tract, a Pleistocene elevated alluvial terrace, along the Karatoya River. Today, the Karatoya is a small river but in the ancient times it was a major river (up to three times wider than the Ganges in the 12^th century AD). According to written sources and ancient maps, the Karatoya River seems to have undergone many changes over the past 2000 years and especially over the last two centuries. As well as, some parts of the site seem to have been damaged by floods according to archaeological findings. However, this active dynamic has never been recorded by sedimentary studies and the available data are incomplete and lack clarification.

This presentation will share an update on the available data and an overview on the new objectives of the research, the methodology (based on a geomorphological approach) and the preliminary results of the first campaign (based on 15 boreholes, 6 stratigraphic sections and 253 samples) in order to reconstruct the environmental history of Mahasthangarh during the different chronological periods of the site occupation.