Suikkanen , E , Huhma , H , Kurhila , M & Lahaye , Y 2014 , ' The age and origin of the Vaasa migmatite complex revisited ' , Bulletin of the Geological Society of Finland , vol. 86 , pp. 41-55 .
Title: | The age and origin of the Vaasa migmatite complex revisited |
Author: | Suikkanen, Einari; Huhma, Hannu; Kurhila, Matti; Lahaye, Yann |
Contributor organization: | Department of Geosciences and Geography |
Date: | 2014 |
Language: | eng |
Number of pages: | 15 |
Belongs to series: | Bulletin of the Geological Society of Finland |
ISSN: | 0367-5211 |
URI: | http://hdl.handle.net/10138/166753 |
Abstract: | The origin of the Vaasa migmatite complex was studied by using whole-rock Sm-Nd and zircon Lu-Hf and U-Pb data in conjunction with whole-rock major and trace element geochemistry. The concordia ages of five Vaasa area granitoid samples are 1.88-1.86 Ga, constraining the age of peak migmatization. The ages of inherited zircon cores in the samples show two clear age populations at 2.02-1.92 Ga and c. 2.7 Ga, which correspond to ages yielded by a mica schist sample from the adjacent Evijarvi belt, as well as with published values for the Evijarvi belt zircon. The initial epsilon(Nd) values of the Vaasa complex samples are relatively unradiogenic (from -3.0 to -2.0). Such values are comparable to a value (-3.6) calculated for the Evijarvi mica schist, as well as to literature values (from 3.0 to -0.5) for the Evijarvi belt. The average initial zircon epsilon(Hf) values of four of the granitoids range from -10 to -5 and are in agreement with the Nd-isotopic results, whereas the northmost sample has a significantly higher value (+1). The deviation is suggested to result from disequilibrium melting of zircon. The isotopic and geochronological data indicate that the Vaasa complex granitoids formed by partial melting of the Evijarvi belt metasedimentary rocks. |
Subject: |
migmatites
granites diatexite metatexite Svecofennian Orogeny partial melting geochronology absolute age zircon U/Pb Lu/Hf Sm/Nd Proterozoic Paleoproterozoic South Ostrobothnia Finland ND ISOTOPIC EVOLUTION SM-ND U-PB SVECOFENNIAN OROGEN CRUSTAL ANATEXIS DETRITAL ZIRCONS SIERRA-NEVADA BALTIC SHIELD LU-HF CONSTRAINTS 1171 Geosciences |
Peer reviewed: | Yes |
Rights: | other |
Usage restriction: | openAccess |
Self-archived version: | publishedVersion |
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