Sulphate Reduction and ~(34)S/~(32)S Effects Related to the Formation of Anoxic Sediment Surfaces in Tidal Sand Flats of the German Wadden Sea (Southern North Sea)

摘要

Local intense sulphate reduction occurs in tidal sand flats of the Wadden Sea of the southern North Sea as a result of the local burial of organic matter (mainly macro algae). The anaerobic degradation of organic matter in the sediment is accompanied by the formation of NH_4, PO_4, CO_2, H_2S and CH_4. When anoxic water reaches the sediment surface it is coloured black by solid FeS_x (leading to what are called 'black spots and areas'), indicating the disturbance of the typical biogeochemical sediment zonation.