Sorted patterned ground in a karst cave, Ledenica pod Hrušico, Slovenia. (3rd January 2018)

• Record Type: Journal Article
• Authors: Obu, Jaroslav; Košutnik, Jure; Overduin, Paul P.; Boike, Julia; Blatnik, Matej; Zwieback, Simon; Gostinčar, Petra; Mihevc, Andrej
• Is Part Of: Permafrost and periglacial processes. Volume 29:Number 2(2018)
• Page Start: 121
• Page End: 130
• Publication Date: 2018-01-03
• Subjects: cave climate -- cave permafrost -- cave sediments -- frost heave -- ice caves -- sorted stripes; Frozen ground -- Periodicals; Sols gelés -- Périodiques; Périglaciaire -- Périodiques; 551.3805
• DOI: 10.1002/ppp.1970
• Languages: English
• ISSNs: 1045-6740

Abstract

Abstract: Patterned ground is a characteristic periglacial landform in polar and alpine environments but has not been systematically studied in karst caves. Here we characterize the periglacial environment and sorted stripes within the Ledenica pod Hrušico ice cave, western Slovenia. The stripes were mapped, sediment depth and grain size were measured, and cave and outside air temperatures were monitored together with ground temperatures. Eleven sorted stripes of coarse limestone debris had developed on 1 m thick silt‐rich sediment, underlain by limestone bedrock. Silt‐rich cave sediments can accumulate as insoluble carbonate residue or during flood events, whereas coarse debris may result from frost shattering. Cold winter air entered the ice cave, but little air exchange occurred during summer, when the cave air temperature slowly rose to a maximum of 5°C. Winter temperature oscillations propagated efficiently to the snow‐free cave floor. Fourteen freeze‐thaw cycles were observed at the patterned‐ground surface during winter 2015/2016 and may cause the differential frost heaving necessary for sediment sorting. Such periglacial conditions and mixtures of silty and coarse sediments can produce sorted patterns in karst caves.