The prospects for the practical use of geothermal water in Latvia are related to the Cambrian and Lower-Middle Devonian aquifers composed of sandstones and siltstones with subordinate shales. Based on the thermal studies of the wells, the two areas of the increased temperatures were defined.
(1) The Southwestern Geothermal Area is defined in SW Latvia, where prospective aquifers were drilled by 29 wells. The temperature of the Cambrian water attains 38ºC – 62ºC at the depths from 1192 to 1714 m. The thickness of the Cambrian aquifer varies from 63 m to 86 m. The temperature of the Lower-Middle Devonian aquifer in the Southwestern Area reaches 20 – 30ºC at the depth of 600 – 775 m. The effective thickness is of the order of 70 – 120 m.
(1) The Eleja Geothermal Area is located in central Latvia. Over 35 wells, which penetrated the prospective aquifers, were drilled in the area. In the southern part of the geothermal area the temperature of the Cambrian reservoir has is 33ºC – 55ºC at the depths from 1100 to 1436 m. The thickness of the Cambrian aquifer varies from 27 to 60 m. The temperature of the Lower-Middle Devonian aquifer in the Eleja Area is 20 – 30ºC at the depths of 400 – 584 m. The thickness of the complex is in the range of 140 – 225 m.
The Latvian Environment, Geology and Meteorology Agency carried out the geothermal project aimed at the data collection and creation of the database of the thermal and geophysical information of the deep wells. The blocks characterising aquifers were prepared. 
This kind of the database and associating maps are essential for better access of the potential users (essentially industry) to the geothermal information. 
The possibility of exploitation of the geothermal waters in Latvia is at the stage of a preliminary evaluation. The investigations aimed at more precise assessment of the geothermal energy resources and evaluation of technological and economic aspects of the use of the geothermal waters is the next stage.

Vilnius, Lithuania