ABSTRACT
Eocene limestone occurs in Bangladesh, at the surface to near-surface in the Sunamganj and Sylhet districts and subsurface in the Joypurhat, Bogra and Naogaon districts, which was deposited under a shallow marine hypo-saline to normal saline condition and warm humid climate. A very narrow strip of Miocene limestone deposit is present in the Sitakunda hills. About 2.8 million tons of Pleistocene limestone deposits are present at St. Martin’s Island of Cox’s Bazar district. The surface to near-surface limestone deposits of Sunamganj area have been calculated as 44 million tons. The subsurface limestone deposits between the depths of 476 m and 514 m at Joypurhat area have been calculated as 12 billion tons in an area of 388.50 sq km, while the deposit in 6.7 sq km of the proposed mining area was 270 million tons. The limestone is fossiliferous, grey, hard, and compact. It contains about 50% CaO with minor amounts of SiO2, Al2O3, and MgO. The limestone has been proven to be good for making Portland cement. Bangladesh needs to revisit the study for the development of an underground mine to meet the demand for clinker/cement.
