Chemical and mineralogical weathering rates and processes in an upland granitic till catchment in Scotland

Bain, Derek C., Mellor, Antony, Wilson, Matthew and Duthie, D. (1994) Chemical and mineralogical weathering rates and processes in an upland granitic till catchment in Scotland. Water, Air, and Soil Pollution, 73 (1). pp. 11-27. ISSN 0049-6979

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Abstract

Weathering in an upland granitic till catchment receiving an intermediate level of acidic deposition has been studied by chemical and mineralogical analyses of soil profiles and chemical analysis of precipitation and streamwater. Long-term weathering rates for base cations calculated from analyses of soil profile horizons using Zr as an internal, immobile, index element are similar for alpine podzols and peaty podzols and are 2–3 meq.m−2.a−1 for Ca and Mg, and 10–11 meq.m−2.a−1 for K and Na. The high loss of Na is associated with the weathering of oligoclase, particularly in the coarse sand fraction. Loss of K is related to weathering of K-feldspar and micas. Current weathering rates for base cations calculated from input-output budgets are higher than long-term rates by factors of 12, 8 and 3 for Ca, Mg and Na, but lower by a factor of 7 for K probably due to biomass uptake. The higher current overall loss of base cations may be due to increased rates of weathering in recent times but this is not conclusive as there are large uncertainties inherent in both methods of estimation.

Item Type:	Article
Subjects:	F800 Physical and Terrestrial Geographical and Environmental Sciences
Department:	Faculties > Engineering and Environment > Geography and Environmental Sciences
Depositing User:	Becky Skoyles
Date Deposited:	09 Jul 2014 08:56
Last Modified:	12 Oct 2019 22:27
URI:	http://nrl.northumbria.ac.uk/id/eprint/17005

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