Nelumwewa Hot Springs

Nelumwewa Thermal Springs or Nelumwewa hot water springs (Sinhala: නෙළුම්වැව උණුදිය උල්පත්) site is one of the major geothermal springs areas in Sri Lanka and is located in Nelumwewa in Polonnaruwa District.

Hot water springs
Geothermal springs are the natural springs that contain hot water (Piyadasa & Ariyasena, 2011). Commonly, thermal springs in the world are associated with volcanic terrain but the hot springs located in Sri Lanka are not related to volcanic activities as the island is not in an active volcanic or tectonic region (Piyadasa & Ariyasena, 2011; Premasiri et al., 2006). Therefore, the waters can get heat either from subsurface heat sources such as large bodies of hot rocks or through deep percolation under the geochemical gradient of the earth (Adikaram & Dharmagunawardhane, 2013). If these waters find weak structural discontinuities leading upward they rise to the surface and emerge as naturally discharging hot water springs (Piyadasa & Ariyasena, 2011).

Nelumwewa springs
The Nelumwewa springs occur close to the boundary between Highland Complex (HC) and Vijayan Complex [(VC) Kumara & Dharmagunawardhane, 2014]. This boundary is a sub-horizontal ductile thrust zone where a number of geologic features are identified. They include major mineralization occurrences such as magnetite, serpentinite, gold, corundum, and calcite as well as formations of hot water springs (Widanagamage, 2011).

The area where the springs are located falls within the dry zone lowlands and has an average elevation of about 30 m above mean sea level. The surface temperature of the spring water is about 61 °C (Kumara et al., 2014).

References
1) Adikaram, A.M.N.M., Dharmagunawardhane, H.A., 2013. Diurnal temperature variations in thermal water springs: A case study at Mahaoya thermal spring cluster, Sri Lanka.
2) Kumara, S.M.P.G.S., Chandrabose, M. and Dharmagunawardane, H.A., 2014. Geothermal Power Generating Capacity of Nelumwewa Thermal Spring Region, Sri Lanka: A Volumetric Assessment. Proceedings of the 30th Technical Session of Geological Society of Sri Lanka. p.16.
3) Kumara, S.M.P.G.S. and Dharmagunawardhane, H.A., 2014. A. geostructural model for the Nelumwewa thermal spring: north-central province, Sri Lanka. Journal of Geological Society of Sri Lanka, 16, pp.19-27.
4) Piyadasa, R.U.K. and Ariyasena, P.R.E.R., 2011. Hydrogeological Characteristics in the Geothermal Springs in Sri Lanka (A case study of the Madunagala and Kinniya geothermal springs).
5) Premasiri, H.M.R., Wijeyesekera, D.S., Weerawarnakula, S. and Puswewala, U.G.A., 2006. Formation of Hot Water Springs in Sri Lanka. Engineer: Journal of the Institution of Engineers, Sri Lanka. p.7.
6) Widanagamage, I.H., 2011. EMPA dating of monazite from high grade metamorphic rocks along the Highland-Vijayan boundary zone, Sri Lanka. MSc thesis, Kent State University. pp.17-18

Location Map
This page was last updated on 17 January 2023
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