GcBÜK400 - Arsenic in the topsoil

Description

Arsenic is a semi-metals, ubiquitous and toxic element. It occurs widely in nature in various mineralizations as arsenic sulfide or oxide and as copper, nickel and iron arsenate. The average as-content of the rocks of the upper continental crust (clarke value) is 2 mg/kg. In the literature, as-contents 20 mg/kg are described as normal contents, with average contents of about 5 mg/kg. Among the toxic elements, arsenic is of particular importance due to its large-scale distribution of elevated contents in Saxon soils. The causes are undoubtedly to be found in the geochemical-metallogenetic specialization of the Fichtelgebirgisch Erzgebirgische Antiklinalzone. The area-related average as-content of the main rock types (petrogeochemical component) is approximately 13 mg/kg. The chalkogenic component is of particular importance in the Ore Mountains. In addition to the element enrichment in the mineralization itself, which was the subject of mining, there was also a large-scale influence on the secondary rocks or their weathering products (primary and secondary geochemical aureoles). The anthropogenic influence on the natural soils is mainly due to the ore processing plants and the emissions from the non-ferrous metal smelters. While in the upper soils of northern and parts of central Saxony low contents dominate (as-poor periglacian sandy to loamy substrates; Loess), a relative accumulation occurs in the weathered soils via solid rocks as a result of the higher petrogenic As component. Significant regional anomalies are found mainly in the Freiberg region (Osterzgebirge), the most important location for mining and smelting polymetallic ores, as well as in the Westerzgebirge (Aue - Ehrenfriedersdorf area). The great extensity and intensity of the distribution of as-minerals in the polymetallic, tin-tungsten and Bi-Co-Ni-Ag-U ore formations as well as their smelting led to large-scale geogenous and anthropogenic enrichments. The two areas are separated by the Northwest-Southeast striking Flöha Zone, an area where there is little ore mineralization and the chacogenic component is rarely developed. Largely elevated as-contents in the soils of the Vorerzgebirgssenke (Zwickau - Chemnitz) are due to the geochemically specialized rotliegendsedimente (including removal products of the Ore Mountains). Particularly high A-levels are found in the floodplain soils of the Freiberger Mulde, Zschopau, Zwickauer Mulde and the Vereinigte Mulde. Due to the geological process of the removal of soils from the ore-mountain deposits as well as anthropogenic inputs by the ore processing and metallurgical industry, there is a constant as-enrichment in the floodplain soils when the river sediments and Schweban parts are deposited in the floodplain areas. As a result of the geogenous and anthropogenic processes described, the test and action values of the Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV) for arsenic are exceeded in some areas in the Ore Mountains and in the floodplain soils of the trough system.

Resources

Name Format Description Link
0 https://luis.sachsen.de/arcgis/services/boden/gcbuek400/MapServer/WFSServer?request=GetCapabilities&service=WFS
21 https://luis.sachsen.de/boden/geodatendownload.html
21 https://luis.sachsen.de/boden/geochemie.html
33 https://umwelt.sachsen.de/umwelt/infosysteme/fme/data/boden/gcbuek400/Steckbrief_GCH_Arsen_2025.pdf
21 https://www.boden.sachsen.de/uebersichtskarten-fuer-schadstoffe-in-boeden-23988.html?_cp=%7B%22accordion-content-23994%22%253A%7B%220%22%253Atrue%7D%252C%22previousOpen%22%253A%7B%22group%22%253A%22accordion-content-23994%22%252C%22idx%22%253A0%7D%7D
0 https://luis.sachsen.de/arcgis/services/boden/gcbuek400/MapServer/WMSServer?request=GetCapabilities&service=WMS

Tags

  • chemisches-element
  • geologie
  • arsen
  • boden
  • chemie
  • anorganischer-schadstoff

Topics

  • REGI
  • ENVI
  • TECH

Categories