Anthropogenic versus geogenic contamination of the Vordernbergerbach valley, Steiermark, Austria: A geochemical, mineralogical and geophysical study

Research output: ThesisDoctoral Thesis

Abstract

A comprehensive geophysical, geochemical and mineralogical study of sediments from alpine river Vordernbergerbach (Styria) starting from its origin (1500 m above sea level) till its confluence point with river Mur at Leoben (540 m above sea level) has been made. The impact of historical mining activity, iron smelting and modern steel production plant has been investigated. Magnetic susceptibility measurements proved a suitable tool to mark the contaminated areas due to heavy metals deposition by iron and steel production plant due to association of heavy metals with spherical magnetite of anthropogenic nature identified with the help of EMPA. Geochemical analysis of Vordernbergerbach sediments and soil collected from Judaskreuzsiedlung near the steel production plant Donawitz/Leoben show a higher heavy metal content at contaminated sites in particular at the localities of Vordernberg and Donawitz/Leoben. The concentration of heavy metals (Cr and Ni) content was found beyond safe limit in the Vordernberg region in sediments. Nickel, Cr, Pb, and Zn concentrations were found to be beyond the safe limit in soil near the Donawitz steel plant. Heavy metals were found associated with anthropogenic particles like magnetites mainly, but also hematites, slag, scale, sinter and roasting ore when analyzed with the help of optical microscopy and electron microprobe analysis (EMPA). A detailed mineralogical study of the heavy mineral fraction of the sediments revealed the fact, that heavy metal are associated with spherical magnetites with a range of diameters from 2.9 g/cm3) was found much higher at contaminated sites at Friedauwerk and Donawitz/Leoben when compared to Gmeingrube. For the first time Laser ablation coupled with ICP-MS was applied to identify the distribution of heavy metals within the carrier particles magnetites mainly. Heavy metals like Cr and Ni were found within the spherical particles and in flakes or scales, while lead was identified as a veneer covering the particles of anthropogenic origin, in soil and dust samples with the help of laser ablation mapping. The lead covering the anthropogenic particles is persisted over ~60 years in the soil. Recent input of heavy metals by the Voest-alpine plant has added more anthropogenic particles/minerals such as apatite, magnesioferrite and ferrosilicon to the list of anthropogenic particles by smelters which can be observed in other regions of with historic iron production. For this reason monitoring of anthropogenic immissions is still necessary, but can be conducted with simple instrumentation such as magnetic susceptibility tools.

Details

Translated title of the contributionAnthropogene versus geogene Kontaminationen im Vodernbergerbachtal, Steiermark, Österreich: Eine geochemische, mineralogische und geophysikalische Studie
Original languageEnglish
QualificationDr.mont.
Supervisors/Advisors
  • Appel, Erwin, Assessor B (external), External person
  • Meisel, Thomas C., Assessor A (internal)
Publication statusPublished - 2012