Gold Ores Related to Shear Zones, West Santa Comba Fervenza Area (Galicia, NW Spain): A Mineralogical Study

Castroviejo Bolibar, Ricardo (1990). Gold Ores Related to Shear Zones, West Santa Comba Fervenza Area (Galicia, NW Spain): A Mineralogical Study. "Mineralium Deposita", v. 25 (n. Suplem); pp.. ISSN 0026-4598. https://doi.org/10.1007/BF00205249.

Descripción

Título: Gold Ores Related to Shear Zones, West Santa Comba Fervenza Area (Galicia, NW Spain): A Mineralogical Study
Autor/es:
  • Castroviejo Bolibar, Ricardo
Tipo de Documento: Artículo
Título de Revista/Publicación: Mineralium Deposita
Fecha: 1990
Volumen: 25
Materias:
Escuela: E.T.S.I. Minas (UPM) [antigua denominación]
Departamento: Ingeniería Geológica [hasta 2014]
Licencias Creative Commons: Reconocimiento - Sin obra derivada - No comercial

Texto completo

[img]
Vista Previa
PDF (Document Portable Format) - Se necesita un visor de ficheros PDF, como GSview, Xpdf o Adobe Acrobat Reader
Descargar (3MB) | Vista Previa

Resumen

Recent research has discovered high-grade Au ores in NNE-SSW trending shear zones in metamorphic proterozoic and palaeozoic terranes, some 40 km NW of Santiago de Compostela (NW Spain). The orebodies are bound to late-stage Hercynian structures, mainly due to brittle deformation, which are superimposed on earlier ductile shear zones, cutting through various catazonal lithologies, including ortho- and paragneisses, amphibolites, eclogites, and granites. Ore mineralogy, alteration, and ore textures define a frame whose main features are common to all prospects in the area. Main minerals are arsenopyrite and pyrite - accompanied by quartz, adularia, sericite, + (tourmaline, chlorite, carbonates, graphite), as main gangue minerals - with subordinate amounts of boulangerite, bismuthinite, kobellite, jamesonite, chalcopyrite, marcasite, galena, sphalerite, rutile, titanite, scheelite, beryl, fluorite, and minor native gold, electrum, native bismuth, fahlore, pyrrhotite, mackinawite, etc., defining a meso-catathermal paragenesis. Detailed microscopic study allows the author to propose a general descriptive scheme of textural classification for this type of ore. Most of the ores fill open spaces or veins, seal cracks or cement breccias; disseminated ores with replacement features related to alteration (mainly silicification, sericitization, and adularization) are also observed. Intensive and repeated cataclasis is a common feature of many ores, suggesting successive events of brittle deformation, hydrothermal flow, and ore precipitation. Gold may be transported and accumulated in any of these events, but tends to be concentrated in later ones. The origin of the gold ores is explained in terms of hydrotherreal discharge, associated with mainly brittle deformation and possibly related to granitic magmas, in the global tectonic frame of crustal evolution of West Galicia. The mineralogical and textural study suggests some criteria which will be of practical value for exploration and for ore processing. Ore grades can be improved by flotation of arsenopyrite. Non-conventional methods, such as pressure or bacterial leaching, may subsequently obtain a residue enriched in gold.

Más información

ID de Registro: 11070
Identificador DC: http://oa.upm.es/11070/
Identificador OAI: oai:oa.upm.es:11070
Identificador DOI: 10.1007/BF00205249
URL Oficial: http://www.springerlink.com/content/l33138163p04q372/
Depositado por: Biblioteca ETSI Minas y Energía
Depositado el: 14 Jun 2012 08:03
Ultima Modificación: 20 Abr 2016 19:14
  • Open Access
  • Open Access
  • Sherpa-Romeo
    Compruebe si la revista anglosajona en la que ha publicado un artículo permite también su publicación en abierto.
  • Dulcinea
    Compruebe si la revista española en la que ha publicado un artículo permite también su publicación en abierto.
  • Recolecta
  • e-ciencia
  • Observatorio I+D+i UPM
  • OpenCourseWare UPM