As geochemical studies on the area of permafrost spreading show, even for ore bodies entirely located in the frozen rock zone, liquid or salt scattering halos are detected on the day surface, which are related to these bodies by origin.

Solubility of gold in solutions of various inorganic compounds has been studied by many researchers. Experiments have been conducted with metallic gold in the form of plates, wire, powder and with thin films of gold on glass. Gold dissolves usually under the action of strong oxidizing reagents, such as free chlorine (its action explains the good solubility of gold in vapor vodka).

In 1951 -1952 we studied hydrogeological conditions of Bayangolskoye coal deposit in south-western Transbaikalia in order to estimate expected groundwater inflows into mine workings. The materials of these studies are the basis of this article. Hydrogeological conditions of Bayangolskoye coal deposit area are characterized by a great variety of ground waters, complexity of conditions of their formation and interrelation, and at the same time they are rather typical for the whole south-western Transbaikalia. Bayangolskoe coal deposit is located in the basin of the Dzhida River in the Zakamensky District of the Buryat-Mongol ASSR (Fig. 1), in the southern piedmont part of the Khamar-Daban Range, on the watershed of the Myla-Burun-Mylykhey Rivers (right slope of the Bayangol Pad). The Khamar-Daban Range is one of the branches of the Eastern Sayan and represents the watershed between the systems of the Dzhida and Irkut rivers.

Hydrogeological observations of groundwater regime are of great importance in the development of fields located in complex hydrogeological conditions. Numerous examples from the practice of development of waterlogged fields show that the cause of groundwater breakthroughs in mine workings is often an insufficient study of hydrogeological conditions of the field and lack of control over the regime of groundwater. Groundwater breakthroughs often delay mining operations for a long time, and their elimination is associated with large expenditures of material and technical resources. But with well-organized hydrogeological observations of the regime of these waters and their correct interpretation usually manages to prevent the occurrence of breakthroughs, and if they occurred, to outline the fastest and most effective ways of their elimination. At the same time, it is essential to identify the source of the breakthrough, which, of course, facilitates the fight against groundwater.