Origin of the Jezero v Ledvicah lake; a depression in a gutter-shaped karstic aquifer (Julian Alps, NW Slovenia)

Abstract

Rožič: Origin of the Jezero v Ledvicah lake; a depression in a gutter-shaped karstic aquifer (Julian Alps, NW Slovenia) The Julian Alps are composed almost exclusively of Triassic to Lower Jurassic carbonates, which results in a karstified high-alpine landscape. In such settings, large water accumulations are not expected and precipitated water drains vertically, gathers in deep, large-scale aquifers, and outflows in large karstic springs located in deeply incised valleys. Some small lakes, however, exist in high alpine areas. Most commonly, they formed above impermeable glacial sediments and are generally characterized by stagnant waters. Jezero v Ledvicah lake, which is one of the seven lakes in the Triglav Lakes Valley, is an exception, because it shows high subaqueous water inflow and outflow and occurs among highly karstified and permeable carbonates. Combining previous research with our new, detailed geological mapping of the lake surroundings and sedimentary research on the Lower Jurassic strata, we propose a hydrogeological model with the aim of explaining the extraordinary behaviour of the lake. We propose that Jezero v Ledvicah lake: A) is part of the "guttershaped" aquifer with perched groundwater that is situated below the floor of the Triglav Lakes Valley; B) barriers of the aquifer are structural (faults and thrust) and stratigraphic (clay interlayers in Lower Jurassic limestone); C) the lake formed in a structural, hydrogeological and morphological depression within this aquifer; D) the groundwater of the aquifer is recharged not solely from the surface directly above the aquifer

Geomorphological and structural characterization of the ‘Canale di Pirro’ polje, Apulia (Southern Italy)

“…Karst is a very peculiar setting, shaped mostly by solution of water on soluble rocks, and forming a variety of typical landforms, at both the surface and underground (Ford & Williams, 2007). Polje (meaning field or large plain in Slav languages) is among the most typical epigean landforms in karst: it is defined as a large, flat-floored, enclosed depression, often with a significant structural control, or developing at the boundary between karst and non-karst rocks (Bonacci, 2004;Dogan, 2003;Gams, 1978Gams, , 2005Gospodarič & Habič, 1979;Gracia et al, 2002Gracia et al, , 2003Nicod, 2003;Pavicic et al, 2002;Rozic et al, 2019). In this work we present a karst geomorphological map of the largest polje in Apulia (southern Italy), the Canale di Pirro polje (Figure 1), marking the landscape of SE Murge, one of the main karst sub-sector of Apulia (Parise, 2011;Sauro, 1991).…”