Rates of Holocene chemical weathering, ‘Little Ice Age’ glacial erosion and implications for Schmidt-hammer dating at a glacier–foreland boundary, Fåbergstølsbreen, southern Norway.

Geraint Owen, John Matthews, Paul Albert

Research output: Contribution to journalArticlepeer-review

Abstract

Average rates of Holocene chemical weathering and `Little Ice Age' glacial erosion of bedrock are estimated across the glacier—foreland boundary of an outlet glacier of the Jostedalsbreen ice-cap, southern Norway. Estimates are derived from two types of evidence: (1) the heights of quartz veins above adjacent surfaces of granitic or granodioritic gneiss; and (2) Schmidt-hammer R-values of rock hardness. Average and maximum rates of surface lowering of gneiss surfaces by chemical weathering are 1.63 and 3.61 mm/ka, respectively, whereas many quartz veins exhibit negligible weathering after c. 9700 years. `Little Ice Age' glacial erosion rates are at least two orders of magnitude greater than the chemical weathering rates, except in a narrow marginal zone inside, but close to, the `Little Ice Age' limit, where patches of weathered surface survive. Bedrock surfaces outside and well inside the `Little Ice Age' glacier—foreland boundary are shown to have potential for improved calibrated-age dating using R-values, compared with moraine surfaces.
Original languageEnglish
Pages (from-to)829–834
Number of pages5
JournalThe Holocene
Volume17
Issue number6
Publication statusPublished - 2007

Keywords

  • Chemical weathering rates
  • denudation
  • Schmidt-hammer
  • Little Ice Age
  • NORWAY

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