Rg. Darmody et al., Weathering implications of water chemistry in an arctic-alpine environment, northern Sweden, GEOMORPHOLO, 34(1-2), 2000, pp. 89-100
This paper reports on some of the chemical characteristics of late melt-sea
son water from Karkevagge ("valley of the boulders") above the Arctic Circl
e in northern Sweden. Included in the analyses were temperature, electrical
conductivity, pH, SO4, NO3, K, SiO2, Mg, Mn, Na, Fe, and Al. These were me
asured in rain, late-lying snow, and water from the major stream and lake,
as well as from pond, tributary,:ind seep sources in the valley. A total of
71 samples was collected at 57 sites between August 6 and August 23, 1996
for the purpose of characterizing the present weathering regime within this
classic U-shaped glacial valley. Evidence of chemical weathering included
increases in solute concentrations over precipitation inputs and a source-r
elated, wide variation in water chemistry. The dominant anion measured in s
urface water was SO4. That, along with the presence of CaSO4 coatings on st
reambeds, indicates that pyrite oxidation may contribute to the weathering
regime. High SO4 concentrations were associated with gypsum-coated streambe
ds and seeps that emerge from the bedrock. Low SO4 concentrations were asso
ciated with tributaries flowing primarily on fresh rock and originating fro
m melting snow. Estimated chemical denudation rate fur the valley, correcte
d for atmospheric inputs, was 19.2 tons/km(2)/yr. Although this is lower th
an previously reported, our research supports earlier work indicating that
chemical weathering is a major component of mass wasting in this arctic-alp
ine environment. (C) 2000 Elsevier Science B.V. All rights reserved.