Facies architecture and palaeoenvironmental constraints of subaqueous felsic volcanism in the Iberian Pyrite Belt: The Paymogo Volcano-Sedimentary Alignment

• Published in: Journal of volcanology and geothermal research Vol. 405; p. 107045
• Main Authors: Donaire, T., Pascual, E., Sáez, R., Toscano, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2020
• Subjects: Hyaloclastite; Iberian Pyrite Belt; Rhyolite; Subaqueous volcanism; VHMS deposits; VHMS deposits; Subaqueous volcanism; Iberian Pyrite Belt; Hyaloclastite; Rhyolite
• ISSN: 0377-0273; 1872-6097
• DOI: 10.1016/j.jvolgeores.2020.107045

The Paymogo Volcano-Sedimentary Alignment (PVSA) is an essentially igneous sequence associated with VHMS deposits of the Iberian Pyrite Belt. Unlike other areas of this mining district, where mafic igneous rocks are abundant, in the PVSA these are essentially felsic. Two facies associations have been distinguished based on petrographic and chemical features: a lower dacite facies association and an upper rhyolite facies association. The main ore horizons appear related to volcanic breccias of the rhyolite facies association. A detailed petrographic study of these breccias suggests they are resedimented hyaloclastite deposits. The analysis of volcanic facies indicates that the volcanism developed at water depths deeper than 500 m, consistent with the minimum depth at which VHMS deposits can form. We conclude that detailed volcanological studies provide effective constraints to palaeoenvironmental interpretations, which are relevant in assessing regional stratigraphy and area selection for VHMS exploration.
•VHMS deposits in the Iberian Pyrite Belt are related in time and space to a specific type of rhyolitic volcanism.•The main ore horizons appear associated to rhyolitic resedimented hyaloclastite deposits.•The analysis of volcanic facies indicates that the volcanism developed at depths greater than 500 m.•Volcanological studies are a major exploration tool in order to select/discard areas in VHMS prospection within the IPB.