Features of the formation of nitrogen thermal springs of Priokhotye
V.E. GLOTOV1, V.V. KULAKOV2
1North-Eastern Interdisciplinary Scientific Research Institute, Far Eastern Branch, Russian Academy of Sciences, Magadan, Russia 2Institute of Water and Ecological Problems, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, Russia
Keywords: springs of thermal groundwater, tectonics, basalt dikes, Late Pleistocene-Holocene regimes of groundwater
Abstract
This article presents a comparative description of the thermal springs occurring on the coast of the Sea of Okhotsk, in the Priokhotye region. In the northern segment of Priokhotye, their groundwater is salty and brackish, mainly of the chloride class. Only one thermal spring (Khiimskii) is a freshwater spring. The water temperature varies from 22 to 63 °C. In the western segment, the water of the thermal springs is fresh, of the bicarbonate class. It is established that the thermal springs are associated with Quaternary dikes of alkaline basalts. The composition of thermal waters is governed by changes in climatic and permafrost conditions, and by fluctuations in the level of the Sea of Okhotsk in the Late Pleistocene-Holocene time. A consequence of these processes in the northern segment of Priokhotye was the introduction of thalassogenic waters to the bowels of the earth 18-9 thousand years ago. In the zone of their contact with the heated dikes of basalts, ascending jets of thermal chloride water appeared. In the western Priokhotye, the conditions in the Late Pleistocene-Holocene period were favorable for the formation of an extensive zone of fresh groundwater. Its contact with high-temperature dikes gives rise to thermal waters, the composition of which is close to the cold waters of the zone of active water exchange. The process of formation of thermal water springs in the valleys of watercourses takes place in two stages. First, the rising thermal jets are dispersed in the zone of active water exchange. Newly formed minerals colmate cracks and pores, forming a heat-removing vent. In the second stage, this vent contributes to the emergence and functioning of the thermal spring.
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