Titre du document / Document title

Pd-bearing oxides and hydrated oxides in mertieite-II crystals from alluvial sediments of the Darya River, Aldan Shield, Russia

Auteur(s) / Author(s)

SHCHEKA G. G. ; LEHMANN B. ; SDLIANIK A. N. ;

Résumé / Abstract

Coarse-grained mertieite-II [Pd₈(Sb,As)₃] crystals (up to 2.5 mm across) with inclusions of sperrylite and intergrown with keithconnite [Pd₃(Te,Bi)], cooperite-braggite, a Pt-Pd-Hg alloy, a (Pd,Pt)₉Te phase and Au-Ag alloy occur in alluvial sediments in the Darya river, Aldan Shield, Russia. The primary PGM assemblage underwent alteration with formation of a very fine-grained mixture of Pd-bearing oxides and hydrated oxides. The Pd oxide/hydrated oxide aggregates (up to 100 μm wide and ∼1 mm long) occur along crystallographic planes, on grain boundaries and fractures, occasionally intergrown with goethite. The Pd-O-bearing compounds formed after (1) mertieite-II (Sb content reaches 23 wt.%), (2) keithconnite (variably enriched in Te, up to 7 wt.% and Bi, up to 6 wt.%) and (3) potarite (with high Hg content, up to 35 wt.%). The variably oxidized and hydrated PGM assemblage can be attributed to supergene alteration and small-scale element redistribution under cool climatic conditions with a limited degree of leaching.

Revue / Journal Title

Mineralogical Magazine   ISSN 0026-461X   CODEN MNLMBB 

Source / Source

2005, vol. 69, n^o6, pp. 981-994 [14 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Mineralogical Society, London, ROYAUME-UNI  (1969) (Revue)

Mots-clés d'auteur / Author Keywords

PGE oxides/hydrated oxides ; mertieite-II ; Darya ; Aldan Shield ; Russia ;

Localisation / Location

INIST-CNRS, Cote INIST : 3052, 35400011518082.0060