REIS, A.I.M. ; SILVA, M.M.V.G. ; ANTUNES, I.M.H.R. (2010) - The Precambrian/Lower Cambrian pluton from Vila Nova. Estudios Geológicos. ISSN 0367-0449. 66:1, p. 51-56.
0367-0449
Title
The Precambrian/Lower Cambrian pluton from Vila Nova
Subject
Granite U-Pb isotopic data Cadomian magmatism
Date
2011-08-03T09:49:22Z 2011-08-03T09:49:22Z 2010
Description
The Vila Nova pluton is a small, Pre-Variscan granitic body that intruded rocks of the Central Iberian
Zone near the contact with the Ossa Morena Zone and is affected by several shear zones and faults. Its
contact metamorphic aureole is constituted by micaschist with porphyroblasts in the outer zone and
hornfels in the inner zone. Small metasedimentar xenoliths are dispersed all over the body. The pluton
has a great mineralogical heterogeneity with pronounced variations in muscovite/biotite and plagioclase/
microcline contents and is classified as granite, granodiorite or tonalite. It is a leucogranite, highly
peraluminous (A/CNK = 1.31 – 1.64), magnesian and calc-alkaline to alkaline-calcic. The variation diagrams
show curvilinear trends with silica. Eu/Eu* = 0.47 – 0.77 and there is a slight enrichment in LREE
relative to HREE. The normalized diagrams indicated dominantly crustal granite, related to subduction.
U-Pb isotopic data of zircon and monazite gives 540-542 Ma age.
