Chemical geothermometers and mineral equilibria of some hot waters in Yugoslavia : Vardar zone and Serbo-Macedonian mass

Abstract

Geochemistry is a relatively young branch of hydrochemistry which is applied in each step of geothermal research and is also one of the less expensive investigation methods. The main goal of geochemistry in surface exploration is predicting of subsurface temperatures. In later stages monitoring of chemical changes in the reservoirs and solving scaling and corrosion problems are common. Yugoslavia is situated within an active tectonic and seismic belt known as the Alpic-Kavkaz-Himalayan belt and in its territory there are found about 300 hot occurences both springs and wells with temperatures of 20-111 C. The geothermal energy in this country is used in health spas, for greenhouse farming and heating. This report deals with chemical data from a part of Yugoslavian hot waters belonging to two tectonic units, the Vardar zone and the Serbo-macedonian mass. The main geological and tectonical features of the Vardar zone are ophiolites, melange and flysch sediments and young magmatic rocks of Quaternary age. The Tertiary grabens covered by young sediments are found in this zone. The Vardar zone is a very active tectonic and seismic zone. The Serbo-macedonian mass represents an older tectonic unit where rocks from Precambrian to Quaternary age are spread. This unit is not as active as the Vardar zone but some seismic areas are found, mostly related to regional faults. In the report 52 chemical analysis from hot springs or wells ...