Mineralogy and mineral chemistry of detrital platinum-group minerals and gold particles from the Elbe, Germany

Abstract > < µ m) of the concentrate are analyzed by reflected-light microscopy, scanning electron microscopy with automated mineralogy software and electron microprobe analysis (EPMA). Other heavy minerals are cassiterite, ferberite, monazite, uraninite, columbite–tantalite, magnetite, zircon and cinnabar. Scanning electron microscopy determined the modal abundance of PGMs, gold and the other heavy minerals. The PGMs are mainly Os–Ir–Ru–(Pt) alloys, Pt–Fe alloys, sperrylite and rustenburgite. Compositional variation of PGMs and gold was analyzed by EPMA. This showed that Pt–Fe alloys are (1) native platinum (> + + ≈ γ >  3.04 apfu. The Os–Ir–Ru–(Pt) alloys show large compositional variations. Platinum and Fe enrichment is typically observed for Ir-rich Os–Ir–Ru alloys. Gold particles often show compositional zoning of Ag-rich cores and Ag-poor rims due to selective leaching of Ag. Similarly, Hg-rich rims of gold particles are analyzed. These are interpreted as the results of in situ amalgamation due to mobilization of Hg from the associated cinnabar particles. The size and shape of the gold particles generally argue for short transportation distances. Similarly, almost euhedral sperrylite and Pt–Fe alloys suggest a source region close to the sampling site. However, roundish Os–Ir–Ru–(Pt) alloys presumably have experienced longer transportation in the river. Gabbroic dikes of the Lusatia block contain sperrylite and gold particles, which can be the source for these particles found in the concentrate. The composition of the Os–Ir–Ru–(Pt) alloys is similar to previous studies on the Vestřev placer in Czech Republic. Both locations are within the drainage area of the Elbe and can therefore be the source of the PGM and gold particles in the concentrate.

Location
Deutsche Nationalbibliothek Frankfurt am Main
Extent
Online-Ressource
Language
Englisch

Bibliographic citation
Mineralogy and mineral chemistry of detrital platinum-group minerals and gold particles from the Elbe, Germany ; volume:35 ; number:4 ; year:2023 ; pages:439-459 ; extent:21
European journal of mineralogy ; 35, Heft 4 (2023), 439-459 (gesamt 21)

Creator
Junge, Malte
Goldmann, Simon
Wotruba, Hermann

DOI
10.5194/ejm-35-439-2023
URN
urn:nbn:de:101:1-2023071304322891722281
Rights
Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
Last update
14.08.2025, 10:44 AM CEST

Data provider

This object is provided by:
Deutsche Nationalbibliothek. If you have any questions about the object, please contact the data provider.

Associated

Other Objects (12)