WYNIKI BADAŃ HYDROGEOLOGICZNYCH W STREFIE WYSTĘPOWANIA GŁĘBOKIEJ WIELOLETNIEJ ZMARZLINY W OTWORZE WIERTNICZYM UDRYŃ PIG 1

Abstract

RESULTS OF HYDROGEOLOGICAL RESEARCH OF THE DEEP PERMAFROST ZONE IN THE UDRYŃ PIG 1 BOREHOLE

Abstract. This paper presents the results of hydrogeological research carried out in the Udryń PIG 1 borehole. It was drilled in order to verify the hypothesis of the occurrence of Pleistocene permafrost in the Suwalki anorthosite massif. The borehole was filtered in Lower Cretaceous fine-grained sand aquifer. Temperature profiling was performed at various intervals, during the thermal stabilization of the borehole, both before and after the pumping test. Minimum water temperature of –0.395°C was recorded in the well at a depth of 383.0 m below the surface. High values of the flow resistance coefficient suggest that the Albian fine – grained sand aquifer is iced, which implies that only part of the water is supplied to the screen. Fast stabilization of drawdown suggests the possibility of a phase transformation process of ice into water by lowering the pressure and forcing the water flow in the aquifer. The hypothesis of the existence of permafrost is unequivocally confirmed by the results of chemical analysis of water samples. The general mineralization, composition and hydrochemical type of the water and ¹⁸O isotope content suggest cryogenic metamorphism.