Subsurface Geological and Hydrogeological Conditions of the Matale District, Sri Lanka: Inferred from Vertical Electrical Sounding Curves

The electrical resistivity method which has important applications in mineral resources and groundwater exploration is used to map variations in the  electrical properties of the subsurface. The study area, the  District of Matale forms a part of the  Central Province of Sri Lanka. The major rock types of the  area consist of crystalline limestone, garnet-sillimanite gneiss, charnockitic gneiss and quartzite. Fifteen  vertical electrical soundings (VES) were carried out in the  Matale District using the  Schlumberger configuration. Initially, fifteen apparent resistivity field curves were analyzed manually. Subsequently IPI2WIN open source software was used for computational interpretation. The  VES points were located mainly in three lithologies; quartzite, crystalline limestone and gneiss. Electrical conductivity of groundwater in the  region was found to be uniform and had no significant salinity-based impact on the  resistivity variations. The majority of resistivity layers obtained from the  VES correlated with the drill logs of same points indicating a considerable degree of relevance for their application as a tool to investigate subsurface geological and hydrogeological conditions.

DOI: http://dx.doi.org/10.4038/ouslj.v6i0.4116

OUSL Journal (2010) Vol. 6, (pp. 91- 102)