Author(s):
Reiser, Fiona K. M. ; Guimarães, Fernanda ; Pinto, Álvaro M. M. ; Matos, João Xavier ; Carvalho, João R. S. ; de Oliveira, Daniel Pipa Soares ; Rosa, Diogo
Date: 2009
Persistent ID: http://hdl.handle.net/10400.9/837
Origin: Repositório do LNEG
Subject(s): Depósitos minerais; Germânio; Calcopirite; Cobre; Barrigão (Concelho de Almodôvar, Portugal); Faixa Piritosa Portuguesa; Depósitos minerais; Depósitos minerais; Germânio; Germânio; Calcopirite; Calcopirite; Cobre; Cobre; Barrigão (Concelho de Almodôvar, Portugal); Barrigão (Concelho de Almodôvar, Portugal); Faixa Piritosa Portuguesa; Faixa Piritosa Portuguesa
Description
Anomalously high germanium contents have been detected by means of whole-rock trace element analysis in remobilised vein type copper ores from the abandoned Barrigão mine, located in the Iberian Pyrite Belt, southern Portugal. The late-Variscan brecciated copper ores consist manly of chalcopyrite, with minor tennantite, rare pyrite and arsenopyrite. The ores, investigated for elements increasingly used in several thin-film and other semiconductor high-technology applications (e.g. indium, selenium, tellurium and germanium), show germanium contents up to 280 ppm, with an average of 61 ppm from 10 samples. Electron Probe Microanalysis of Barrigão ore samples revealed that germanium is contained in chalcopyrite, with a range of 0.1 to 0.4 wt% (0.23 wt% average). High germanium contents seem to be linked to "dirty" chalcopyrite phases, showing irregular patchy zoning under the microscope and on back-scattered electron images.
