%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture non répertoriées par l'AERES
%A Michel, D.
%A Giuliani, Gaston
%A Pulz, G.M.
%A Jost, H.
%T Multistage gold deposition in the Archaean Maria Lazara gold deposit (Goias, Brazil)
%D 1994
%L fdi:41481
%G ENG
%J Mineralium Deposita
%@ 0026-4598
%K GEOCHIMIE ; OR ; GITOLOGIE ; MINERALOGIE ; PARAGENESE
%K BRESIL ; GOIAS
%K MARIA LAZARA REGION
%N 29
%P 94-97
%U https://www.documentation.ird.fr/hor/fdi:41481
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_35-36/41481.pdf
%W Horizon (IRD)
%X The Maria Lazara gold deposit in the Archaean Guarinos greenstone belt, central Brazil, consists of quartz-carbonate veins formed in a ductile shear zone. Study of the sulphides and gold-bearing quartz-carbonate veins and veinlets of the potassic hydrothermal alteration zone reveals two stages of ore paragenesis. The first stage corresponds to S-rich arsenopyrite deposition and the second one to the precipitation of As-rich arsenopyrite and Bi-Te-Au-S phases. Modes of occurrence, textures and Ag contents of native gold define two types of gold. The first type is native gold with Ag contents greater than 5 wt % postdating the S-rich arsenopyrites. The second type has Ag contents less than 3 wt % and is contemporaneous with Bi-Te-S phases. (Résumé d'auteur)
%$ 064GEOCHI