Genesis and evolution of a Paleoproterozoic basement inlier within West Gondwana addressed by Sm-Nd isotopic geochemistry and Zr saturation thermometry

Genesis and evolution of a Paleoproterozoic basement inlier within West Gondwana addressed by Sm-Nd isotopic geochemistry and Zr saturation thermometry

This paper presents new isotopic Sm-Nd ID-TIMS data and applies the Zr saturation thermometry on orthogneisses of the Quirino Complex to address the mechanisms of magma genesis, evolution and tectonic setting. Quirino Complex is considered a Paleoproterozoic basement inlier within a Neoproterozoic b...

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Bibliographic Details
Published in:Journal of South American earth sciences Vol. 80; pp. 95 - 106
Main Authors: Valladares, Claudia Sayão, Duarte, Beatriz Paschoal, Machado, Hugo Tavares, Viana, Samuel Magalhães, Figueiredo, Pedro Lontra Costa de
Format: Journal Article
Language:English
Published: Elsevier Ltd 01-12-2017
Online Access:Get full text
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Summary:This paper presents new isotopic Sm-Nd ID-TIMS data and applies the Zr saturation thermometry on orthogneisses of the Quirino Complex to address the mechanisms of magma genesis, evolution and tectonic setting. Quirino Complex is considered a Paleoproterozoic basement inlier within a Neoproterozoic belt, comprised of two distinct calcalkaline magmatic suites: a Siderian to Rhyacian high-K suite (2.30–2.19 Ga); and a Rhyacian medium-K suite (2.17–2.16 Ga). High zircon solubility and εNd(t) values (+2.7 to −5.8) indicate that the protoliths of the high-K suite gneisses can be related to high-temperature (TZr = ca. 810 °C) I-type granites. The gneisses of the medium-K suite display isotopic signature for crustal residence (εNd(t) = −17.9 and −8.1). Their protoliths, rich in inherited zircons (ca. 3.0 Ga) and other restitic/refractory components (hornblende clots and mafic enclaves), were derived from partial melting of Archean crust at relatively low temperature (TZr = ca. 750 °C) within a collisional tectonic setting. •Juvenile to continental arc magmatism at 2.3–2.19 Ga generated at high temperature.•Restite-bearing collisional magmatism at 2.17–2.16 Ga generated at low temperature.•Collisional magmatism generated by partial melting of Archean crust −3.40–2.85 Ga old.•TTG-greenstone association matches the Archean source requirements.
ISSN:0895-9811
1873-0647
DOI:10.1016/j.jsames.2017.09.005