Michel D. auteur aut IRD Giuliani Gaston auteur aut IRD Pulz G.M. auteur aut IRD Jost H. auteur aut IRD text journalArticle eng text/pdf reformatted digital access 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) specialized GEOCHIMIE OR GITOLOGIE MINERALOGIE PARAGENESE BRESIL GOIAS 064GEOCHI 29 94-97 1994 0026-4598 https://www.documentation.ird.fr/hor/fdi:41481 0026-4598 [F B41481] 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 IRD - Base Horizon / Pleins textes 1995-05-15 2015-07-02 fdi:41481 fre