Summary
This report documents the hydrochemical analyses performed on water samples collected during a field expedition in August 2013 to two former hydrocarbon exploration boreholes (>2 km deep) in the West Siberian artesian megabasin. The sample sites were at Byelii Yar and at Goryachii Istochnik (near Parabel'), both in Tomsk oblast'. In neither case did the boreholes encounter significan hydrocarbon reserves; they currently overflow under artesian pressure at the surface and their geothermal water is used in simple spa resorts. In both cases, the waters are highly reducing; they contain H2S and methane (CH4) as dissolved gases, and they do not contain detectable concentrations of sulphate and nitrate. Both waters are rich in barium (an indicator of sulphate reduction) and strontium (an indicator of long residence time).
