Syngenetic sand veins and anti-syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

Murton, Julian B. and Bateman, Mark D. (2007) Syngenetic sand veins and anti-syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada. Permafrost and Periglacial Processes, 18 (1). pp. 33-47. ISSN 1045-6740

[img]
Preview
PDF
Download (139kB) | Preview

Abstract

Sand-sheet deposits of full-glacial age in the Tuktoyaktuk Coastlands, western Arctic Canada, contain syngenetic sand veins 1-21 cm wide and sometimes exceeding 9 m in height. Their tall and narrow, chimney-like morphology differs from that of known syngenetic ice wedges and indicates an unusually close balance between the rate of sand-sheet aggradation and the frequency of thermal-contraction cracking. The sand sheets also contain rejuvenated (syngenetic) sand wedges that have grown upward from an erosion surface. By contrast, sand sheets of postglacial age contain few or sometimes no intraformational sand veins and wedges, suggesting that the climatic conditions were unfavourable for thermal-contraction cracking. Beneath a postglacial sand sheet near Johnson Bay, sand wedges with unusually wide tops (3.9 m) extend down from a prominent erosion surface. The wedges grew vertically downward during deflation of the ground surface, and represent anti-syngenetic wedges. The distribution of sand veins and wedges within the sand sheets indicates that the existence of continuous permafrost during sand-sheet aggradation can be inferred confidently only during full-glacial conditions.

Item Type: Article
Additional Information: Publisher's version available at official URL
Keywords: sand sheets • sand veins • sand wedges • permafrost • thermal-contraction cracking • deflation • aggradation
Schools and Departments: School of Global Studies > Geography
Subjects: G Geography. Anthropology. Recreation > G Geography (General)
Depositing User: Chris Keene
Date Deposited: 25 Sep 2007
Last Modified: 10 Mar 2017 18:17
URI: http://sro.sussex.ac.uk/id/eprint/1594
Google Scholar:13 Citations

View download statistics for this item

📧 Request an update