Study of Economic Minerals and Rock Types Around Weilawaya Region

Abstract

The presence of mineral deposits along the Highland Complex (HC) -ViJayan Complex (VC) boundary o f Sri Lanka has not yet been thoroughly studied. This study was carried out to identify the economically important mineral deposits and rock types along the Highland -ViJayan boundary particularly in the Wellawaya region. The boundary between Highland Complex and ViJayan Complexes being convergent plate boundaries is ideal for mineralization. The identification o f economic mineral and rock occurrences hold a potential for further study of Highland - Vijayan boundary and its mineralization. The stream sediments samples o f Kirindi oya basin were studied. Panning, seiving, and other heavy minerals separation methods were used to concentrate the heavy mineral from the stream sediments. Thin section were use to study rock samples collected from the bedrock. The Gem minerals specially corundum, garnets and tourmaline and colour changing garnets were found around this region. Only few localities with in-situ corundum were found. However they are not in gem quality and not very economically valuable. A high weight percentage o f gem-indicator mineral show the possible gem occurrences in the vicinity. The economic mineral deposits provide a basic for all kinds o f industrial and regional development. All these economically important rocks and minerals such as vein quartz, feldspar, and magnesit with large extent and the in-situ gem occurrences can be used to increase the well being o f the society in the area around Wellawaya