“…Although the Sundarbans is considered to be of recent origin, the large accommodation space exists due to accretion and erosion with historical relative sea-level variability (Goodbred and Kuehl, 2000;Tyagi and Sen, 2019). Therefore, the Sundarbans might have a 3m organic layer in the seaward direction and much more in the landward (Allison et al, 2003).…”