Cryogenic Cave Pearls In the Periglacial Zones of Ice Caves

0390419 - GLÚ 2013 RIV US eng J - Článek v odborném periodiku
Žák, Karel - Orvošová, M. - Filippi, Michal - Vlček, M. - Onac, B. P. - Persoiu, A. - Rohovec, Jan - Světlík, Ivo
Cryogenic Cave Pearls In the Periglacial Zones of Ice Caves.
Journal of Sedimentary Research. Roč. 83, č. 2 (2013), s. 207-220. ISSN 1527-1404. E-ISSN 1938-3681
Grant CEP: GA ČR GAP210/10/1760
Výzkumný záměr: CEZ:AV0Z30130516
Institucionální podpora: RVO:67985831 ; RVO:61389005
Klíčová slova: caves * cryogenic caves * ice caves * periglacial zones
Kód oboru RIV: DB - Geologie a mineralogie
Impakt faktor: 1.943, rok: 2013

The Carpathian Mountains across Slovakia and Romania are home of several ice caves located at elevations between 700 and 1,200 m above sea level (asl). Although the mean surface annual temperature is above the freezing point, perennial ice deposits are common in caves and shafts with certain morphologies (large entrances followed by steep vertical or downward-sloping passages), into which the dense cold winter air sinks and remains trapped all year round. A particular type of cave pearls (cryogenic cave pearls, CCPs) occur in spatially restricted accumulations or extensive pearl fields (layers locally up to 0.5 m in thickness) within the scree covering the cave floor in the periglacial zone of these caves. The temperature in the periglacial zone oscillates around the freezing point, promoting seasonal ice formation. A similar type of pearl is observed in the entrance section of other caves that experience temporary freezing conditions during the cold season. When compared to pearls of non-iced caves, those from ice caves always occur at sites where liquid water cannot accumulate. CCP formation in nests with drips or in cave pools surrounded by rimstone dams is therefore excluded. Freezing–thawing processes are responsible for moving the pearls, preventing their cementation to the floor or between them. Seasonal water freezing and frost action in the cave periglacial zone is a necessary condition for the formation of these pearls.
Trvalý link: http://hdl.handle.net/11104/0219285