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What and where are periglacial landscapes?

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Version 2 2023-06-12, 09:40
Version 1 2023-06-09, 22:43
journal contribution
posted on 2023-06-12, 09:40 authored by Julian MurtonJulian Murton
Uncertainties about landscape evolution under cold, nonglacial conditions raise a question fundamental to periglacial geomorphology: what and where are periglacial landscapes? To answer this, with an emphasis on lowland periglacial areas, the present study distinguishes between characteristic and polygenetic periglacial landscapes, and considers how complete is the footprint of periglaciation? Using a conceptual framework of landscape sensitivity and change, the study applies four geological criteria (periglacial persistence, extraglacial regions, ice-rich substrates, and aggradation of sediment and permafrost) through the last 3.5 million years of the late Cenozoic to identify permafrost regions in the Northern Hemisphere. In limited areas of unglaciated permafrost regions are characteristic periglacial landscapes whose morphology has been adjusted essentially to present (i.e., Holocene interglacial) process conditions, namely thermokarst landscapes, and mixed periglacial–alluvial and periglacial–deltaic landscapes. More widespread in past and present permafrost regions are polygenetic periglacial landscapes, which inherit ancient landsurfaces on which periglacial landforms are superimposed to varying degrees, presently or previously. Such landscapes comprise relict accumulation plains and aprons, frost-susceptible and nonfrost-susceptible terrains, cryopediments, and glacial–periglacial landscapes. Periglaciation can produce topographic fingerprints at mesospatial scales (103–105 m): (1) relict accumulation plains and aprons form where long-term sedimentation buried landsurfaces; and (2) plateaux with convexo–concave hillslopes and inset with valleys, formed by bedrock brecciation, mass wasting, and stream incision in frost-susceptible terrain.

History

Publication status

  • Published

File Version

  • Published version

Journal

Permafrost and Periglacial Processes

ISSN

1045-6740

Publisher

Wiley

Page range

1-27

Department affiliated with

  • Geography Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

Legacy Posted Date

2021-01-13

First Open Access (FOA) Date

2021-02-11

First Compliant Deposit (FCD) Date

2021-01-13

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