Volcanic architecture in the Odiel river area and the volcanic environment in the Riotinto–Nerva Unit, Iberian Pyrite Belt, Spain

• Published in: Journal of volcanology and geothermal research Vol. 202; no. 1; pp. 29 - 46
• Main Authors: Valenzuela, A., Donaire, T., González-Roldán, M.J., Toscano, M., Pascual, E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 30.04.2011; Elsevier
• Subjects: Crystalline rocks; Earth sciences; Earth, ocean, space; Exact sciences and technology; Freshwater; Iberian Pyrite Belt; Igneous and metamorphic rocks petrology, volcanic processes, magmas; massive sulfide deposits; rhyolite; Spain; volcanic facies associations; Iberian Peninsula; Southern Europe; Europe; Spain; Spain, Galicia; Spain, Andalucia, Huelva, Odiel R; massive sulfide deposits; Iberian Pyrite Belt; volcanic facies associations; rhyolite; Spain; rivers; depositional environment; iron sulfides; geologic sections; volcanic rocks; eruptions; igneous rocks; mining; rhyolites; pyrite; genesis; lithofacies; organization; sills; style; sulfides
• ISSN: 0377-0273; 1872-6097
• DOI: 10.1016/j.jvolgeores.2010.12.018

In order to assess the volcanic architecture of the VSC in the Iberian Pyrite Belt, Spain, a study of the volcanic and sedimentary lithofacies has been undertaken on a section up to 1000 m thick in the Odiel river, considered to be also representative of other areas of the Riotinto–Nerva Unit. Among other mineral deposits, this unit includes the world-class volcanic-hosted massive sulfide deposits of the Riotinto mining district. Several conclusions have been obtained: a) a complex, thick volcanic succession, as well as mafic and felsic sills and thin sedimentary intervals, predated the genesis of the sulfide deposits, which did not form in a dominantly sedimentary environment; b) two successive, felsic volcanic sequences can be distinguished, showing textural and chemical variations from bottom to top; c) mafic lithofacies decrease upwards in the sequence, and d) volcanic structures, eruption style and internal organization suggest a deep subaqueous depositional environment, which agrees with the depositional setting for massive sulfide deposits. ► The Odiel river is not a sill-sediment complex, but a bimodal volcanic succession. ► Basic rocks are more abundant towards the bottom of the stratigraphic column. ► We distinguish two contrasting rhyolitic successions. ► We describe submarine felsic volcanic rocks, partly constituting Neptunian deposits. ► VHMS deposits in the Riotinto-Nerva unit postdate a thick volcanic succession.