One of the Many Caves Dug by the Rak Along Its Life. Shortly, the Water Digs the Limestone to Make Its Way and Creates Caves, then the Vault of the Caves Collapses and the Karst Geography Changes, Continuously; Notranjsko-Kraška Regija, Slovenija
In the (periodic) phases of flood, the cave is COMPLETELY filled with water, as can be seen from the dry mud traces limit on the entrance rocks, highlighted by a note.
19-june-2020: the Rakov Škocjan area is not in its own right, but is part of the largest system of karstsism phenomena of the Internal Karst, all linked to a single river basin that extends, surface up and down, from the permeable polje of Babno (748m a.s.l.) to the resurgences of the Ljubljanica in Vrhnika (293m a.s.l.).
It's a short but very complex set.
All karstsism, with its superficial and deep phenomena, is given by the interaction of water with the permeable calcareous soil alternating with the impermeable, mainly sedimentary one.
To describe what a watercourse can do in a predominantly calcareous environment, and in particular to describe this example, it would take much more time and many more words.
For curiosity, the "Stream of Many Names", which collects and represents ALL the surface waters (which are a minimal part of the total), of a large part of the Inner Karst (municipalities of Cerknika, Bloke and Loška Dolina), starts in the Babno Polje subsoil (748m), just to the north of Mount Snežnik (1796m), while it emerges for the first time in the contiguous Loška Dolina (574m) with 2 springs that on the impermeable soil of this basin, give life to the Obrh and Veliki Obrh streams, which last, with the waters of the first , after a couple of kilometers, it returns underground to reappear a little further west, in the vast impermeable basin of Cerknica (551m), with the name of Jezerščica, which acts as a tributary of the intermittent lake of the same name; from Cerkniško jezero the emissary is called Stržen and this too will be swallowed at the foot of a rocky wall that divides this impermeable plain from the Rakov Škocjan valley (512m), dug into the limestone of the karst plateau for tens of meters by the same waters that here they call Rak; everything is repeated when the waters of the Rak meet permeable limestone rocks and, through sinkholes, end up underground until they find an impermeable bottom and there they intersect the Pivka creek, architect of the famous Postojna Caves, which counts the contributions of these other two Internal Karst municipalities (Pivka and Postojna); everything emerges in the entrance hall of the Planina Cave and from here flows towards the periodic flood plain (446m) of the Planina little town, where, with the last name, the Unica stream writhes for 6km before disappearing into deep sinkholes on the opposite side from where it (re-)spring.
These (exclusively) Karst waters will emerge for the last time, with dozens of springs from the ground, and then remain open up to the Black Sea, where the Karst Region ends, or where the impermeable plain of Ljubljana begins, also called Barje, at about 290m average altitude above sea level.
One of the Many Caves Dug by the Rak Along Its Life. Shortly, the Water Digs the Limestone to Make Its Way and Creates Caves, then the Vault of the Caves Collapses and the Karst Geography Changes, Continuously; Notranjsko-Kraška Regija, Slovenija
In the (periodic) phases of flood, the cave is COMPLETELY filled with water, as can be seen from the dry mud traces limit on the entrance rocks, highlighted by a note.
19-june-2020: the Rakov Škocjan area is not in its own right, but is part of the largest system of karstsism phenomena of the Internal Karst, all linked to a single river basin that extends, surface up and down, from the permeable polje of Babno (748m a.s.l.) to the resurgences of the Ljubljanica in Vrhnika (293m a.s.l.).
It's a short but very complex set.
All karstsism, with its superficial and deep phenomena, is given by the interaction of water with the permeable calcareous soil alternating with the impermeable, mainly sedimentary one.
To describe what a watercourse can do in a predominantly calcareous environment, and in particular to describe this example, it would take much more time and many more words.
For curiosity, the "Stream of Many Names", which collects and represents ALL the surface waters (which are a minimal part of the total), of a large part of the Inner Karst (municipalities of Cerknika, Bloke and Loška Dolina), starts in the Babno Polje subsoil (748m), just to the north of Mount Snežnik (1796m), while it emerges for the first time in the contiguous Loška Dolina (574m) with 2 springs that on the impermeable soil of this basin, give life to the Obrh and Veliki Obrh streams, which last, with the waters of the first , after a couple of kilometers, it returns underground to reappear a little further west, in the vast impermeable basin of Cerknica (551m), with the name of Jezerščica, which acts as a tributary of the intermittent lake of the same name; from Cerkniško jezero the emissary is called Stržen and this too will be swallowed at the foot of a rocky wall that divides this impermeable plain from the Rakov Škocjan valley (512m), dug into the limestone of the karst plateau for tens of meters by the same waters that here they call Rak; everything is repeated when the waters of the Rak meet permeable limestone rocks and, through sinkholes, end up underground until they find an impermeable bottom and there they intersect the Pivka creek, architect of the famous Postojna Caves, which counts the contributions of these other two Internal Karst municipalities (Pivka and Postojna); everything emerges in the entrance hall of the Planina Cave and from here flows towards the periodic flood plain (446m) of the Planina little town, where, with the last name, the Unica stream writhes for 6km before disappearing into deep sinkholes on the opposite side from where it (re-)spring.
These (exclusively) Karst waters will emerge for the last time, with dozens of springs from the ground, and then remain open up to the Black Sea, where the Karst Region ends, or where the impermeable plain of Ljubljana begins, also called Barje, at about 290m average altitude above sea level.