Thermal Waters of Bulgaria: Present Use and Probable Origin

Abstract

Bulgaria is a country that is presently undergoing crustal shortening. It is also a country that has many geothermal manifestations. To date, most geothermal studies have dealt with areas undergoing crustal extension. Moderate temperature resources may be expected in compressional areas that, like Bulgaria, have virtually no indication of recent igneous activity. For such areas, the most likely heat source in recently faulted radiogenic rocks similar to the granite so prevalent in the Balkan and Rila Mountains of Bulgaria. As compressional areas tend also to be areas of mountain building, their moderate temperature resources find ready application in space heating. In Bulgaria, present usage is primarily balneological and horticultural; however, direct heat is used to process linen, and antibiotics area being produced from algae grown in carefully monitored ponds fills with geothermal fluid. As in other geothermal regimes, in Bulgaria there is a direct correlation between regional seismicity ad geothermal resources potential. Trace element analysis of groundwater has been highly developed in Bulgaria as an exploration aid in the search for subterranean mineralized thermal waters.