Genesis of the zoned granitic pluton of Penamacor-Monsanto, central Portugal

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Authors:Neiva, A. M. R.; da Costa Campos, T.
Author Affiliations:Primary:
Universidade de Coimbra, Departamento de Ciencias da Terra, Coimbra, Portugal
Universidade Federal do Rio Grande do Norte, Brazil
Volume Title:Memorias e Noticias, Publicacoes do Museu e Laboratorio Mineralogico e Geologico de Universidade de Coimbra
Source:Memorias e Noticias, Publicacoes do Museu e Laboratorio Mineralogico e Geologico de Universidade de Coimbra, Vol.114, p.51-68. Publisher: Universidade de Coimbra, Departamento de Ciencias da Terra e do Museu Mineralogico e Geologico, Coimbra, Portugal. ISSN: 0373-6474
Publication Date:1992
Note:In English with Portuguese summary. 13 refs.; illus., incl. 4 tables, geol. sketch map
Summary:This Hercynian peraluminous pluton consists of hydrothermally altered porphyritic granites with two micas. The unaltered granites representative of the two main lithologies are coarse- to medium-grained and occur along the margin, while a more evolved, coarse-grained granite comprises the core. Between these is intruded a medium-grained granite from which is derived a more evolved granite intruded between the margin and a bordering complex of schist and metagreywacke. The highest degrees of hydrothermal alteration occur at the margin and close to the core. Aplite veins and masses and quartz veins cut some of the granites. Major and trace element data of the unaltered rocks, micas and plagioclase suggest there are two magmatic sequences. Least squares modelling of major elements was unsuccessful probably due to volatile loss. The granitic rocks were generated at ∼ 3-3.5 kbar, 690°C and fO2 of 10-16 to 10-17 bars. Log fH2O/fHCl increases and log fH2O/fHF and log fHCl/fHF decrease in both sequences. [R.E.S.]
Subjects:Alteration; Aplite; Chemical ratios; Crystal chemistry; Crystal fractionation; Electron probe data; Emplacement; Feldspar group; Fractional crystallization; Framework silicates; Fugacity; Genesis; Granites; Hydrothermal alteration; Igneous rocks; Intrusions; Least-squares analysis; Magmas; Major elements; Metasomatism; Mica group; Mineral composition; Orogeny; P-T conditions; Partition coefficients; Petrography; Plagioclase; Plutonic rocks; Plutons; Porphyritic texture; Sheet silicates; Silicates; Statistical analysis; Structural controls; Textures; Trace elements; Variscan Orogeny; Zoning; Europe; Iberian Peninsula; Portugal; Southern Europe; Central Portugal; Monsanto Portugal; Penamacor Portugal
Coordinates:N400000 N401000 W0070000 W0071000
Abstract Numbers:96M/3599
Record ID:2018096898
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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