Late-Quaternary cryostratigraphy of a coastal cliff at Martha Point, southwest Banks Island, western Canadian Arctic
A 5 m thick unlithified sequence consisting of sands, silts and minor peats crop out in a coastal cliff within continuous permafrost. A well-exposed 70 m long section displayed a range of epigenetic ice wedges. These could be classified into three generations, each at a different stratigraphic level...
Published in: | The Holocene |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
SAGE Publications
2000
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Subjects: | |
Online Access: | http://dx.doi.org/10.1191/095968300675687786 http://journals.sagepub.com/doi/pdf/10.1191/095968300675687786 |
Summary: | A 5 m thick unlithified sequence consisting of sands, silts and minor peats crop out in a coastal cliff within continuous permafrost. A well-exposed 70 m long section displayed a range of epigenetic ice wedges. These could be classified into three generations, each at a different stratigraphic level. The oldest was truncated by a major thaw unconformity which was overlain by a bed of highly involuted silts with peat clasts, interpreted as evidence of a deep palaeoactive layer and associated thermokarst. This bed forms part of a regionally extensive thermokarst phase, correlated with an early-Holocene Climatic Optimum. The other two ice-wedge horizons postdate the thermokarst event with the youngest approximating to the base of the modern active layer. |
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