Texture, chemistry, and mineralogy of acid soil profiles in Hailand, SW Sweden

Abstract

The texture, chemistry, mineralogy, and weathering features of acid soil profiles in Halland, SW Sweden, have been studied. Most of the investigated soils consist of sandy‐silty glacial till with a varying gravel content (12–25 wt.% of material <20 mm) and usually a few per cent in the <2 μm fraction. The soil profiles in southernmost Halland (Laholm municipality) are more acid at lower depths relative to the others. Quartz, plagioclase, K‐feldspar, amphiboles (hornblende) and a mineral phase with a 1.4 run XRD reflection (chlorite or chlorite‐vermiculite) dominate the mineralogy of soil samples <0.5 mm. Weathering is most intensive in the E and Bsl horizons as indicated by a thin‐section examination of two selected soil profiles. Weathering features consist of strongly altered feldspar grains and extensive coatings or fillings by Fe oxides and clay minerals. The clay mineral suite of the <2 μm fraction is characterized by varying proportions of smectite and hydroxy‐Al inter‐layered vermiculite in the E horizon, and hydroxy‐Al interlayered ver‐miculite in the Bsl‐C horizons. Biotite, chlorite, and amphiboles are considered precursors of these clay minerals. Some kaolinite was found in the shallower horizons.

Sjöström, J. & Lin, Z., 1996: Texture, chemistry, and mineralogy of acid soil profiles in Halland, SW Sweden. GFF, Vol. 118 (Pt. 4, December), pp. 227–236. Stockholm. ISSN 1103–5897.

Keywords:

• Acid soils
• soil texture
• soil chemistry
• XRD
• weathering
• clay mineralogy
• soil profile
• Halland
• Sweden