MONA and Minerals
In search of valuable raw materials in Sri Lanka
Sri Lanka's geological history is exceptionally fascinating. Some 200 million years ago, the Indian subcontinent separated from the supercontinent Gondwana, colliding with the Asian plate approximately 155 million years later. In the process, Sri Lanka became detached from the Indian mainland following a series of tremendous earthquakes and volcanic eruptions. Not only can the traces of this eventful history still be clearly seen today, they are also of great interest for the extraction of raw materials useful for nuclear engineering, renewable energy and other high technologies.
In what is probably one of the most extensive, systematic studies of geological characteristics, Sameera et al. of the Geological Survey and Mines Bureau (GSMB) in Sri Lanka surveyed the entire south-west region of the country with a 2 x 4l MONA system, focussing particularly on thorium and uranium. In addition to promising deposits, they pinpointed 19 locations with a natural dose rate of over 600 nSv/h. Allowing for the K-40 contribution, the survey even recorded 2.3 µSv/h near the town of Uragasmanhandiya – the equivalent of an annual dose of over 20 mSv.
At the same time, occurrences of the rare-earth pegmatite, monazite, with its typically high thorium content, were detected during the survey. This indicates potential sources of the rare-earth elements, which are becoming increasingly important for industrial processes, and therefore more valuable. They are used first and foremost in cutting-edge, resource-efficient high technologies. As a result, the GSMB and MONA have done the emerging economy a great service in several respects, both in terms of radiation protection and by opening up promising economic prospects of extracting raw materials.
The complete study has been published by the Journal of Geological Society of Sri Lanka and is available online.
ENVINET – Leading in Environmental Radiation Detection