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标题：Geochemistry of Soils and Streams on Surfaces of Varying Ages in Arctic Alaska
其他标题：Geochemistry of Soils and Streams on Surfaces of Varying Ages in Arctic Alaska
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作者：Katy Keller ; Joel D. Blum ; George W. Kling 等
期刊名称：Arctic, Antarctic, and Alpine Research
印刷版ISSN：1523-0430
电子版ISSN：1938-4246
出版年度：2007
卷号：39
期号：1
页码：84-98
DOI：10.1657/1523-0430(2007)39[84:GOSASO]2.0.CO%3B2
摘要：Climate change may bring about geochemical changes in arctic regions as a result of increasing thaw depth. In order to better understand current watershed geochemistry and mineral weathering and provide a basis for predicting the geochemical effects of active-layer thickness increase, we examined elemental chemistry and 87 Sr/ 86 Sr of streams and sequential and total digests of soils, permafrost, and soil parent materials from seven glacial deposit surfaces of varying geomorphic ages in arctic Alaska in the vicinity of the Philip Smith Mountains quadrangle (69°N, 150°W). We found overall greater exchangeable K concentrations, exchangeable and acid digestible P and Ca concentrations, acid digestible and total Ca/Na and Ca/Sr, and lower acid digestible 87 Sr/ 86 Sr in permafrost than in active-layer mineral soil. Of the surfaces with similar parent material, stream and soil data suggest that weathering has progressively depleted calcium carbonate in the active layer with increasing surface age. Our results suggest that increasing thaw depth will lead to increasing carbonate and Ca supply to soils and streams, as well as spatially variable increases in P and K supply. Geochemical differences between active-layer soil and permafrost suggest the possibility of using stream geochemistry to detect changes in active-layer thickness in watersheds.