Findings of acid sulfate soil in Väröbacka

Abstract

Acid sulfate soil (AS soils) is naturally occurring soil, formed under waterlogged and hypoxic or anoxic conditions with high sulfide material content that produces sulfuric acid when oxidized. AS soils can be classified as potential or active AS soils. Active AS soils are formed when potential AS soil is exposed to atmospheric oxygen, reducing the soil pH. AS soil can cause negative environmental and health impact because of its low pH and metal leaching. It is therefore important to map and investigate where AS soils are located. This thesis investigates the presence of AS soils in Väröbacka, Halland, using field sampling, H2O2 oxidation and ICP-SFMS analyses. The results shows that AS soils exist in Väröbacka, both active and potential AS soil. The AS soils are located in soil mapped as postglacial fine sediments in low elevation. Based on the stratigraphic and shoreline displacement recorded, we suggest that the sediment that became an AS soil was formed during Tapes transgression. The effect of AS soil on the environment in Väröbacka is unclear and demand further investigations.