Norra,S., Lanka-Panditha,M., Ktamar,U. and Stuben(uの頭に¨),D.(2006): Mineralogical and geochemical patterns of urban surface soils, the example of Pforzheim, Germany. Applied Geochemistry, 21, 2064-2081.


 This study presents a combined geochemical and mineralogical survey of urban surface soils. Many studies on urban soils are restricted to purely chemical surveys in order to investigate soil pollution caused by anthropogenic activities such as traffic, heating, industrial processing, waste disposal and many more. In environmental studies, chemical elements are often distinguished as lithogenic and anthropogenic elements. As a novel contribution to those studies, the authors combined the analysis of a broad set of chemical elements with the analysis of the main mineralogical phases. The semi-quantification of mineralogical phases supported the assignment of groups of chemical elements to lithogenic or anthropogenic origin. Minerals are important sinks for toxic elements. Thus, knowledge about their distribution in soils is crucial for the assessment of the environmental hazards due to pollution of urban soils. In Pforzheim, surface soils (0-5 cm depth) from various land use types (forest, agriculture, urban green space, settlement areas of various site densities) overlying different geological units (clastic and chemical sediments) were investigated. Urban surface soils of Pforzheim reflect to a considerable degree the mineral and chemical composition of parent rocks. Irrespective of the parent rocks, elevated concentrations of heavy metals (Zn, Cu, Pb, Sn, Ag) were found in soils throughout the whole inner urban settlement area of Pforzheim indicating pollution. These pollutions will tend to accumulate in inner urban surface soils according to the available adsorption capacity, which is normally higher in soils overlying limestone than in soils overlying sandstone. However, inner urban surface soils overlying sandstone show elevated concentrations of carbonates, phyllo-silicates and Fe and elevated pH values compared with forest soils overlying sandstone. Thus, in comparison to forest soils overlying sandstones, inner urban soils overlying sandstone affected by pollution concurrently posses elevated concentrations of mineral phases typically providing relatively high adsorption capacities for heavy metals.』

1. Introduction
2. Area of investigation
3. Methodology
 3.1. Sampling and sample preparation
 3.2. Analyses
4. Results
5. Discussion
 5.1. Spatial distribution of trace metal pollution of Pforzheim surface soils
 5.2. The urban vs. geogenic impact on the mineral and geochemical composition of surface soils
  5.2.1. The mineral and geochemical composition of the ground mass of Pforzheim surface soils
  5.2.2. Residual phases and weathering products
 5.3. Soil density and soil fraction of coarse grains
6. Summary and conclusions