Variability in the mineral magnetic properties of soils and sediments within a single field in the Cape Fold mountains, South Africa: Implications for sediment source tracing

Little difference was found between the low frequency magnetic susceptibility of quartzite topsoils and the shale and sandstone topsoils found elsewhere in the Eastern Cape. However, igneous sources such as dolerite are far more magnetic than the quartzite topsoils. Discrimination between sediment sources can be highly variable within the < 63 μm fraction. For example, the < 10 μm fraction of soils from the study site had a higher magnetic susceptibility than Karoo shales (sieved to < 63 μm), whilst the 63-32 μm fraction had a lower susceptibility than the Karoo shales.