Paleoproterozoic Dacite Dykes of the Vorontsovka Terrane, Volga-Don Orogen: Geochemistry, Age and Petrogenesis-Reference-Cited by-同舟云学术

Paleoproterozoic Dacite Dykes of the Vorontsovka Terrane, Volga-Don Orogen: Geochemistry, Age and Petrogenesis

Published:2024-07-24 Issue:2 Volume:32 Page:139-153
ISSN:0869-5903
Container-title:Петрология
language:
Short-container-title:Petrologiâ

Author:

Savko Konstantin A.¹,Samsonov Aleksandr V.²,Korish E. H.¹,Bazikov Nikolay S.¹,Larionov Aleksandr N.³

Affiliation:

1. Voronezh State University

2. Institute of Ore Geology, Petrography, Mineralogy and Geochemistry RAS

3. Karpinsky Russian Geological Research Institute

Abstract

The metamorphosed dacitic porphyry dykes were established for the first time in the western part of the Vorontsovska terrane, which is located in the Paleoproterozoic Volga-Don orogen at the margin of Archean Sarmatia and Volga-Ural cratons. The magmatic protolith age for the metadacites is ca. 2.07 Ga. They are ferrous, metaluminous rocks of calc-alkali series and belong to I-type granitoids. Sodium specialization, low concentrations of Mg, Cr, Ni, incoherent elements with sufficient REE fractioning and absence of Eu*-anomalies, high Sr/Y ratio and especially (Gd/Yb)n values (10), and also radiogenic Nd isotopic composition suppose the juvenile mafic source for the dacitic melts. According to petrogenetic estimations, such conditions could be caused by partial melting of depleted N-MORB type basites at the equilibrium with the eclogitic restite. Supposed mechanism for the dacitic magmas forming is the partial melting of the basites from the lower horizons of crust with highly enlarged thicknes (60 km) due to preceding collision processes.

Publisher

The Russian Academy of Sciences

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