caa a22 4500 467890250 CHVBK 20180406152747.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s00710-006-0127-7 doi (NATIONALLICENCE)springer-10.1007/s00710-006-0127-7 Tellurides, selenides and Bi-mineral assemblages from the Río Narcea Gold Belt, Asturias, Spain: genetic implications in Cu-Au and Au skarns [Elektronische Daten] [A. Cepedal, M. Fuertes-Fuente, A. Martín-Izard, S. González-Nistal, L. Rodríguez-Pevida] Summary: Gold ores in skarns from the Río Narcea Gold Belt are associated with Bi-Te(-Se)-bearing minerals. These mineral assemblages have been used to compare two different skarns from this belt, a Cu-Au skarn (calcic and magnesian) from the El Valle deposit, and a Au-reduced calcic skarn from the Ortosa deposit. In the former, gold mineralization occurs associated with Cu-(Fe)-sulfides (chalcopyrite, bornite, chalcocite-digenite), commonly in the presence of magnetite. Gold occurs mainly as native gold and electrum. Au-tellurides (petzite, sylvanite, calaverite) are locally present; other tellurides are hessite, clausthalite and coloradoite. The Bi-bearing minerals related to gold are Bi-sulfosalts (wittichenite, emplectite, aikinite, bismuthinite), native bismuth, and Bi-tellurides and selenides (tetradymite, kawazulite, tsumoite). The speciation of Bi-tellurides with Bi/Te(Se + S) ≤ 1, the presence of magnetite and the abundance of precious metal tellurides and clausthalite indicate fO2 conditions within the magnetite stability field that locally overlap the magnetite-hematite buffer. In Ortosa deposit, gold essentially occurs as native gold and maldonite and is commonly related to pyrrhotite and to the replacement of löllingite by arsenopyrite, indicating lower fO2 conditions for gold mineralization than those for El Valle deposit. This fact is confirmed by the speciation of Bi-tellurides and selenides (hedleyite, joséite-B, joséite-A, ikunolite-laitakarite) with Bi/Te(+ Se + S) ≥ 1. Springer-Verlag, 2006 Cepedal A. Department of Geology, University of Oviedo, Spain aut Fuertes-Fuente M. Department of Geology, University of Oviedo, Spain aut Martín-Izard A. Department of Geology, University of Oviedo, Spain aut González-Nistal S. Río Narcea Gold Mines, Spain aut Rodríguez-Pevida L. Río Narcea Gold Mines, Spain aut Mineralogy and Petrology Springer-Verlag 87/3-4(2006-07-01), 277-304 0930-0708 87:3-4<277 2006 87 710 https://doi.org/10.1007/s00710-006-0127-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00710-006-0127-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cepedal A. Department of Geology, University of Oviedo, Spain aut NATIONALLICENCE 700 1- Fuertes-Fuente M. Department of Geology, University of Oviedo, Spain aut NATIONALLICENCE 700 1- Martín-Izard A. Department of Geology, University of Oviedo, Spain aut NATIONALLICENCE 700 1- González-Nistal S. Río Narcea Gold Mines, Spain aut NATIONALLICENCE 700 1- Rodríguez-Pevida L. Río Narcea Gold Mines, Spain aut NATIONALLICENCE 773 0- Mineralogy and Petrology Springer-Verlag 87/3-4(2006-07-01), 277-304 0930-0708 87:3-4<277 2006 87 710 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer