Presencia de la amalgama Au-Ag-Hg en el Cinturón Piritico Ibérico, mina de la Zarza, (Huelva)

Abstract

In the La Zarza Mine gold is found as native gold and as Au-Ag-Hg amalgam first discovered in the Iberlam Pyritic Belt. The average amalgam composition obtained by Microprobe Data analyses is A u 03(/ \ g 052Hg0 W. This composition Is similar to that obtained In two massive volcanogenetlc deposits in Canada and Sweden, except for the La Zarza's higher Hg content. Cold deposition took place in two distinct periods: in the first, as native gold included in pyrite; in the second, as an Au-Ag-Hg amalgam, during the pyrite recrystallization process. During this process gold was released, together with silver and mercury, towards the pyrite microfractures by solid state diffusion