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6950300 
Journal Article 
Trace element signature of pyrite from Bagassi gold deposit, western Burkina Faso 
Dakoure, HS; Eglinger, A; Andre-Mayer, AS; Seta, N; Toe, WAB; Siebenaller, Luc; , 
2019 
SOC GEOLOGY APPLIED MINERAL DEPOSITS-SGA 
GENEVA 4 
679-682 
WOS:000503111600176 
The Bagassi gold deposit is situated on the Hounde greenstone belt. It is a high-grade (1.8 million tons @ 11.47 g/t) deposit in which mineralization is located at the contact between volcanic mafic rocks and granitoids. Two types of mineralization were observed. (i) gold disseminated within sulfides within host-rock and ankerite-rich veinlets and (ii) as free particles within quartz-rich tension gashes. Two types of pyrite associated to gold events were identified. Py-1 is generally overgrown by Py-2 which contain native gold inclusions. LA-ICP-MS data reveal that Py-1 is enriched in trace elements (Median Au = similar to 4 ppm, median As = similar to 9000 ppm) compared to Py2 which have median Au = 0.01 ppm and median As = similar to 320 ppm ppm. Py-1 and Py-2 show approximately the same range for Ni, Co, Zn, Te and Se and are both depleted in Cu, Sb, Ag, Bi and Pb (Median < 2 ppm). At 55 Zone gold mineralization refers to a single hydrothermal event associated to remobilized gold (gold fineness > 906). Earlier stage of this event consist of an As-Au rich fluid with incorporation of primary gold into As rich Py-1 lattice. The later stage implicates an Au-oversaturated fluids forming free gold nuggets in the quartz-rich veins related to second generation Py-2. 
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15th SGA Biennial Meeting on Life with Ore Deposits on Earth 
Glasgow, SCOTLAND