Analysis of the Spontaneous Flow Phenomenon of the Land Above Ferdinand Salt Mine– Coştiui (Maramureş)

Abstract On July 21 st 2025, a flow of rocks mixed with water took place in Coștiui (Maramureș), from the surface, in the underground excavations of Ferdinand mine (which operated between 1828-1934), at the limit of its southern shaft, which generated on the surface, in the southern vicinity of the county road DJ 186A, a collapse cone of approx. 1500m 3 . The article develops the geo-mechanical phenomenon and the causes that led to the occurrence of this spontaneous phenomenon, the rehabilitation measures and the safety of the affected area.