Littva J., Bella P., Gaál Ľ., Holúbek P. & Hók J., 2017: Extraordinary geology and fault-controlled phreatic origin of the Zápoľná Cave (Kozie chrbty Mountains, Slovakia). Acta Geologica Slovaca, 9, 1, 25–34.

Extraordinary geology and fault-controlled phreatic origin of the Zápoľná Cave (Kozie chrbty Mountains, Slovakia)

Juraj Littva^1,2, Pavel Bella^2,3, Ľudovít Gaál², Peter Holúbek⁴ & Jozef Hók¹

¹Department of Geology and Palaeontology, Faculty of Natural Sciences, Comenius University, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava, Slovakia; littva@fns.uniba.sk, hok@fns.uniba.sk
²State Nature Conservancy of the Slovak Republic, Slovak Caves Administration, Hodžova 11, 031 01 Liptovský Mikuláš, Slovakia; pavel.bella@ssj.sk
³Catholic University in Ružomberok, Pedagogical Faculty, Department of Geography, Hrabovská cesta 1, 034 01 Ružomberok, Slovakia
⁴Slovak Museum of Nature Protection and Speleology, Školská 4, 031 01 Liptovský Mikuláš, Slovakia

Abstract

The Zápoľná Cave is located in the SW part of the Kozie chrbty Mountains in the valley of the Čierny Váh River. It is formed in the carbonates of the Gutenstein Formation, right above the décollement plane of the Svarín Partial Nappe (belonging to the Hronic Unit). The rocks bear marks of intensive brittle deformation indicating that the nappe emplacement occurred in relatively cold conditions. The fine-grained sandstone, considerably atypical for the purely carbonate Gutenstein Formation, occurs in the cave. It probably reflects the transition from the underlying siliciclastic Šuňava Formation, which most likely acted as a tectonic lubricant during the nappe translation, and is at present tectonically amputated from the Svarín Partial Nappe. The cave passages follow mainly faults or joints with two general types of orientation – the N–S direction and the E–W directions. Their contribution to the genesis of the cave was not only passive but also active, as they show the signs of the neotectonic activity. Based on the speleomorphological features, the cave evolution is divided into three phases: (I) deep in phreatic zone when the majority of the cave volume was formed by slowly circulating water along the discontinuities (mainly steep faults/joints) in the host rock; (II) in epiphreatic zone characterized by the appearance of the water table in the middle parts of the cave, and followed by its slow fall; and (III) in vadose zone after the water table decline, is characterized mainly by collapse processes. The evidence from cave morphology and fills suggests that there was no ponor through which the Čierny Váh River could enter the cave directly. The phases of the cave evolution, along with the activity of the E–W-trending discontinuities, could be linked to the activity of the Vikartovce Fault located in the south-eastern part of Kozie chrbty Mts., which was active up to Late Quaternary.

Key words: karst, phreatic morphology, Western Carpathians, neotectonics, Hronic Unit, nappe décollement

Manuscript received: 2016-07-01

Revised version accepted: 2016-09-22