HYDROTHERMAL ACTIVITY IN THE BAIKAL RIFT ZONE: RECENT HOT SPRINGS AND DEPOSITS OF PALEOTHERMAL WATERS

Abstract

Thermal springs, which are widely developed within the Baikal rift zone (BRZ), form a NE-trending zone extending from the upper course of the Olekma River in the northeast to the Selenga River mouth in the southwest. Thermal springs are rare west of Lake Baikal. Springs, mainly represented by nitric thermal waters of variable composition, mark recent hydrothermal activity in the BRZ. This zone also contains deposits of paleothermal water represented by travertines and geyserites. Travertines can be deposited within a wide range of temperatures, from cold water inclusive. However, they are mostly deposited from thermal water, the temperature of which in the study region can vary from 20 to 70° C. As togeyserites, the minimal temperatures of their formation do not fall below 70°C. We found geyserites on the western coast of Lake Baikal at the southwestern extension of the above-mentioned zone of hydrothermal activity.