The TTG-Amphibolite Terrains of Arctic Fennoscandia : Infinite Networks of Amphibolite Metatexite-Diatexite Transitions

Show full item record



Permalink

http://hdl.handle.net/10138/318181

Citation

Halla , J 2020 , ' The TTG-Amphibolite Terrains of Arctic Fennoscandia : Infinite Networks of Amphibolite Metatexite-Diatexite Transitions ' , Frontiers in Earth Science , vol. 8 , 252 . https://doi.org/10.3389/feart.2020.00252

Title: The TTG-Amphibolite Terrains of Arctic Fennoscandia : Infinite Networks of Amphibolite Metatexite-Diatexite Transitions
Author: Halla, Jaana
Contributor: University of Helsinki, University Management
Date: 2020-06-30
Language: eng
Number of pages: 14
Belongs to series: Frontiers in Earth Science
ISSN: 2296-6463
URI: http://hdl.handle.net/10138/318181
Abstract: The Earth's early basaltic crust converted episodically into felsic TTG (tonalite-trondhjemite-granodiorite) crust by unknown tectonic processes. To contribute to the debate on the possible tectonic settings of TTGs, this article illustrates and explains migmatite structures of Meso- to Neoarchean TTG-amphibolite terrains in Arctic Fennoscandia. The Lake Inari and Rommaeno complexes in northern Finland and West Troms Complex in northern Norway consist of folded and banded TTG gneisses with abundant amphibolite enclaves. The terrains show migmatite structures generated byin situand in-source melting of amphibolites and repeated metatexite-diatexite transitions that form infinite and boundless interconnected networks over vast areas. The aim of this article is to show that the TTGs of these terrains represent coalescedin situand in-source neosomes of amphibolite protoliths and are not similar to granitoidssensu strictogenerated by modern-style plate tectonics. The structures of the TTG-amphibolite associations of Arctic Fennoscandia suggest intracrustal differentiation by syn-anatectic partial melting of amphibolites in deep parts of a thick mafic crust.
Subject: Archean
TTG
amphibolite
metatexite
diatexite
CONTINENTAL-CRUST
EVOLUTION
CONSTRAINTS
GENERATION
GRANITOIDS
MIGMATITES
TECTONICS
ROCKS
FIELD
1171 Geosciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
feart_08_00252.pdf 12.96Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record