A pilot study on the mineralogical and geochemical characteristics of a recently discovered in-situ beryl occurrence at Kaltota, South Central Sri Lanka

Abstract

Recently discovered in-situ beryl occurrence at Kaltota, southcentral Sri Lanka was studied by a pilot study of soil survey to probe its mineralogical and geochemical characteristics. Overall mineralization of the occurrence comprises of beryl, garnet, tourmaline, quartz, topaz and zircon. Beryl and tourmaline occur mainly as scattered detrital grains and as gravity-enriched elluvial concentrations within the overburden. Geological evidences suggest subsurface extension of the mineralization in host pegmatite and in contact zone. Total of 18 soil samples were collected from a preplanned grid within the site and, mineralogical analysis was performed on the panned heavy mineral concentrates of soils. In chemical analysis, soil samples were treated with both aqua regia digestion and alkali fusion method followed by Atomic Absorption Spectrometry (AAS). With the better results, alkali fusion method was chosen to obtain be concentrations in the soils. The results of the mineralogical analyses shows an existence of beryl and other gem minerals in different proportions in the heavy concentrates, which are in comparison with the anomalous Be concentrations found in the chemical analyses of soils. The results are to be further examined by a detailed study, probably followed by drilling to elucidate subsurface distribution of the mineralization.