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Metallogenic features of Miocene porphyry Cu and porphyry-related mineral deposits in Ecuador revealed by Re-Os, 40Ar/39Ar, and U-Pb geochronology

Schütte, Philip ; Chiaradia, Massimo ; Barra, Fernando ; Villagómez, Diego ; Beate, Bernardo

In: Mineralium Deposita, 2012, vol. 47, no. 4, p. 383-410

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    Titel
    • Metallogenic features of Miocene porphyry Cu and porphyry-related mineral deposits in Ecuador revealed by Re-Os, 40Ar/39Ar, and U-Pb geochronology
    Autor
    • Schütte, Philip. Department of Mineralogy, University of Geneva, Rue des Maraîchers 13, 1205, Geneva, Switzerland
    • Chiaradia, Massimo. Department of Mineralogy, University of Geneva, Rue des Maraîchers 13, 1205, Geneva, Switzerland
    • Barra, Fernando. Department of Geosciences, The University of Arizona, Gould-Simpson Building, 1040 East Fourth St, 85721, Tucson, AZ, USA
    • Villagómez, Diego. Department of Mineralogy, University of Geneva, Rue des Maraîchers 13, 1205, Geneva, Switzerland
    • Beate, Bernardo. Escuela Politecnica Nacional, Quito, Ecuador
    Dokumententyp
    • Postprint
    Sprache
    • Englisch
    Veröffentlicht in
    • Mineralium Deposita, 2012, vol. 47, no. 4, p. 383-410. Springer-Verlag
    Andere elektronische Ausgabe
    OAI-PMH-ID
    • oai:doc.rero.ch:320178
    Summary
    Mineralization and alteration events at ten Miocene porphyry Cu and porphyry-related epithermal mineral deposits in southern, central, and northern Ecuador were dated by means of molybdenite Re-Os, biotite and alunite 40Ar/39Ar, and titanite U-Pb geochronology. Most of these hydrothermal events show a spatio-temporal correlation with porphyry intrusion emplacement as constrained by zircon U-Pb ages. The total age range for these events spans the 23.5-6.1Ma period, without displaying systematic along- or across-arc age distribution trends. While epithermal deposits tend to be spatially associated with volcanic rocks of a similar age, porphyry Cu deposits in Ecuador are frequently spatially associated with deeper-seated basement units and batholith-scale precursor intrusive systems assembled over ≥5m.y. time periods. In most cases, formation of the porphyry Cu deposits is related to the youngest magmatic (-hydrothermal) event in a given area, postdating batholith construction at a regional scale. The majority of Miocene deposits occurs in southern Ecuador where areally extensive, post-mineralization (late Miocene to recent) volcanic sequences with the potential to conceal mineralization at depth are lacking. Only few Miocene deposits occur in northern-central Ecuador, where they mainly crop out in the Western Cordillera, west of the productive present-day volcanic arc. The surface distribution of post-mineralization arc volcanism reflects along-arc variations in subducting slab geometry. Porphyry Cu and epithermal deposits in Ecuador define a Miocene metallogenic belt broadly continuous with its coeval counterpart in northern-central Peru. Although both belt segments were formed in an overall similar tectonomagmatic and metallogenic setting, their respective metal endowments differ significantly