Characterization of heavy minerals in Nilaveli and Batticaloa beach stretches

Abstract

The northeastern coast of Sri Lanka is notable for its significant heavy mineral deposits, especially the Pulmoddai deposit (containing 70-85 wt% heavy minerals) and the Verugal deposit (containing 45-50 wt% heavy minerals). However, regions like Batticaloa and Nilaveli remain underexplored and show potential. This study conducted a comparative analysis of these two beaches stretches to characterize their heavy mineral content in beach sand. Twenty-four composite samples were collected along the Batticaloa (n=17) and Nilaveli (n=7) stretches. Bromoform separation was used to determine their heavy mineral contents, followed by petrographic microscopic grain counting to ascertain the volumetric percentage of each heavy mineral type. The results revealed a higher mineral content in the Batticaloa beach stretch (1.20-14.50 wt%) compared to Nilaveli (0.36-6.42 wt%), despite Nilaveli's proximity to the Mahaweli River. The Batticaloa beach stretch showed average contents of 53.14% ilmenite, 2.06% rutile, 6.44% garnet, 31.94% zircon, and 4% monazite, indicating a significant potential for economically valuable monazite. The high heavy mineral content identified in the Batticaloa beach stretch suggests that further detailed explorations are warranted to assess the economic viability of the deposit.