Gold as a powerful proxy to trace gold and unravelling gold systems, an insight into French Guiana (France)

International audienceDespite of the gold exploration since 150 years, there is a limited understanding of gold deposits in the French Guiana. To improve our knowledge, alluvial, eluvial and primary gold grains from the Sophie-Repentir and Saint-Elie goldfields (French Guiana) have been characterised by EPMA and LA-ICP-MS analyses. Preliminary results show a good discrimination between the two orogenic gold districts. Whereas the gold grains population of the Saint-Elie is characterised by a low content of silver (i.e. mainly less than 6 wt%), a suite of Bi mineral inclusions and a Sb-Bi-Cd fingerprint, gold from the Sophie-Repentir is enriched in silver (up to ~ 20 wt%), Cu-poor and associated with a wider range of tellurides. These features also allow matching an alluvial gold population to its corresponding lode source with confidence and raise questions about the processes controlling the trace elements behaviour