Secondary sorting of sorted patterned ground

• Published in: Permafrost and Periglacial Processes
• Main Author: Warburton, Jeff
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1990
• Subjects: Kapp Linné; Permafrost and Periglacial Processes; Spitzbergen
• Online Access: http://dx.doi.org/10.1002/ppp.3430010312; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.3430010312; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.3430010312

Abstract The arrangement of small sorted patterns within the central fine domain of a larger sorted circle (herein called 'secondary sorting') was observed at two patterned ground sites: Arikaree Cirque, Colorado Front Range, USA, and Kapp Linné, Western Spitzbergen. Large polygons do not appear to be randomly filled by smaller ones of all sizes. The size of the inset polygons seems to be related to the dimensions of the larger form. Preliminary field survey suggests that large forms are filled by smaller polygon sizes in a width ratio of approximately 1:2.5‐3. Subdivision of the fine centres occurs in 77% of the sorted polygons at the Colorado site ( n = 100) but only 42% of patterns at Kapp Linné (n = 31). Possible explanations of the scaling of the secondary polygons include pore water and/or soil convection and desiccation cracking. Desiccation crack systems simulated in a laboratory experiment are similar to those observed in the field.