GcBÜK400 — Copper in the upper floor

Copper is an essential element for the diet of all living beings, which, however, can lead to toxic effects in the event of an extreme oversupply. The mean Cu content of the rocks of the upper continental crust (Clark value) is 14 mg/kg. Analogous to chromium and nickel, it is mainly enriched in basic rocks (Diabase, Basalte, Metabasite). The mean Cu content (mediane) of the main Saxon rock types ranges from 2 to 67 mg/kg, and the regional Clarke of the Ore Mountains/Vogtland is 23 mg/kg. Geogenic Cu enrichments can be found mainly in the Ore Mountains via the widely used mineralisations here. Chalkopyrite (copper jaw) is common in almost all mineral associations as so-called pass-through minerals. Strong anthropogenic Cu entries are mainly caused by non-ferrous metallurgy. Due to the diverse use of Cu, e.g. in electrical engineering, as alloy metal, piping material and rain gutters, the element is also increasingly entered into the wastewater. For uncontaminated soils Cu levels from 2 to 40 mg/kg are considered normal. The regional distribution of Cu levels in the upper soil is mainly determined by the geogenic proportion of substrates. Due to the increased Cu levels of the diabase widespread in the Vogtland (58 mg/kg), the point-like tertiary basaltoids (60 mg/kg) and the locally stored amphibolites (46 mg/kg) of the metamorphic basement, there is anomalously high Cu content in the weathering soils above the said solid rocks. Increased solubility influence (with relatively low Cu content of about 12 mg/kg) can lead to a “dilution effect” via Cu-rich substrates, depending on the proportion of the solution (e.g. via the monzonitoid at bites). Extremely low Cu concentrations can be observed in weathering soils over acidic magmatites (Granite of Ei-Benstock, Teplice-Rhyolite), metagranitoids (central zone of ore), sandstones (Elbe sandstone and Zittau mountains) and soil societies from periglaciar sandy deck sediments in northern axes. Important regional anomalies are mainly located in the Freiberg region, the most important former site of mining and the smelting of polymetallic ores. However, the anthropogenic entries are usually limited to the immediate vicinity of the metallurgical sites. This leads to overlay with geogenic proportions in the soil, which are causally linked to the spread of copper gravel leading mineral associations. Analogous conditions can be found, albeit in a weakened form, in the Schneeberg — Schwarzenberg — Annaberg-Buchholz — Marienberg area. Especially high Cu-contents have the meadow soils of the Freiberger Mulde. After the entry of the Freiberger Mulde into the Freiberg mining and metallurgy area, there is a sustainable material burden on the floodplains, which extends across the Aue of the United Mulde to the northern border. Increased Cu levels, but at a much lower level, also occur in the floodplains of the Zwickau Mulde, where the polymetallic mineralisations of the West Ore Mountains are located in the catchment area. As a result of the geogenic and anthropogenic processes described above, in the meadows of the Freiberger and the United Mulde, the measures of the Federal Soil Protection and Contaminant Ordinance (BBodSchV) for grassland use (sheep farming) are partially exceeded.