Rock glacier lakes – a distinct lake subtype: a case study at Hridsko Jezero, (Bogičevica Mountain, Montenegro)

This article presents a new concept on the genesis of a distinct subtype of glacial lakes. Hridsko jezero is one of the few lakes in the mountain Bogicevica in southeast Montenegro (part of Prokletije massif, along the borders with Kosovo and Albania). Situated at 1970 m a.s.l., the lake is suggested to fill depressions of a giant relict rock glacier, developed on the NW slopes of the peaks Hridski krs (2358 m a.s.l.) and Bogicevicki krs (2374 m a.s.l.). Such a theory should be accepted as a reconsideration of the older views on lake’s origin, which postulated that this was a glacial lake in a staircase cirque, formed after a several stadium retreat of Wurmian glaciers on Prokletije. Only very few lakes of such genesis exist in the mountains of the Balkan Peninsula. The article discusses on the main stages of rock glacier lake formation