TY - JOUR

T1 - Rates of Holocene chemical weathering, ‘Little Ice Age’ glacial erosion and implications for Schmidt-hammer dating at a glacier–foreland boundary, Fåbergstølsbreen, southern Norway.

AU - Owen, Geraint

AU - Matthews, John

AU - Albert, Paul

PY - 2007

Y1 - 2007

N2 - 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.

AB - 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.

KW - Chemical weathering rates

KW - denudation

KW - Schmidt-hammer

KW - Little Ice Age

KW - NORWAY

M3 - Article

VL - 17

SP - 829

EP - 834

JO - The Holocene

JF - The Holocene

SN - 0959-6836

IS - 6

ER -