『Abstract
　Changes in the normative mineralogy and chemical weathering rates (elemental loss) of Ca and Mg from the uppermost mineral soil horizon were determined at five forested sites in the boreal zone forming a chronosequence. The sites were all located on the same glaciofluvial (esker) deposit (well-sorted sand) over a distance of 27 km in the coastal region of the Gulf of Bothnia in Finland and had estimated ages from 339 to 5276 years. Because of isostatic land uplift the region is continually emerging from the sea, the rates of which are known, allowing the age of current surfaces to be dated. Soil profile development progressed from Gleyic Arenosols (youngest and nearest the coast) through Haplic Arenosols to Haplic Podzols (3 oldest and furthest away from the coast). Elemental concentrations of soil (＜2 mm) were determined using XRF and ICP-MS from a hot aqua regia digest. Normative mineralogy was determined using these data and a stoichiometric mineral distribution model. Weathering (elemental loss) rates were calculated using XRF concentrations and normative quartz as the conservative reference component. Quartz was increasingly enriched in the uppermost horizon with soil age, commensurate with the loss of easily weathered minerals. Using quartz as the conservative component, the mass residual fraction remaining in the uppermost soil horizon of the oldest soil was 0.27, 0.35 and 0.57 respectively for biotite, hornblende and anorthite, which are important sources of Ca and Mg. B/E-horizon ratios of hydrous aluminosilicate contents increased from 1 to 14 with soil age clearly indicating the increase in degree of podzolisation. The losses of Ca and Mg increased with soil age but at a decreasing rate. Ca and Mg losses for the youngest soil were respectively 3.3 and 1.8 mol m^-2; corresponding values for the oldest soil were 10.6 and 10.5. Mean rates of loss for the youngest soil were 10 and 5 mmol m^-2 yr^-1 for Ca and Mg respectively, and corresponding values for the oldest soil were 2 mmol m^-2 yr^-1 for both Ca and Mg. The loss of these base cations from the soil will have resulted in a lower acid neutralizing capacity and increased sensitivity of these soils to acidic deposition, and represents a reduction in the soil reserve of important plant nutrients.

Keywords: Normative mineralogy; Soil formation; Base cations; Gulf of Bothnia; Land uplift』

1. Introduction
2. Materials and methods
　2.1. The chronosequence, soil age and sampling
　2.2. Chemical analyses and calculation of normative mineralogy
　2.3. Mineral and element weathering losses
3. Results
　3.1. Elemental concentrations and soil normative mineralogy
　3.2. Changes in normative mineralogy with soil age
　3.3. Losses of soil material, Ca and Mg with soil age
4. Discussion
　4.1. Methodological considerations
　4.2. Normative mineral and elemental losses
5. Conclusions
Acknowledgements
References