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Magma pulses in the Central Variscan Belt: episodic melt generation and emplacement during lithospheric thinning
Author(s) -
Schaltegger Urs
Publication year - 1997
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.1997.tb00021.x
Subject(s) - geology , magmatism , lithosphere , geochemistry , crust , petrology , tectonics , paleontology
Magmatism in the central part of the Variscan orogenic belt in Europe has occurred in several distinct episodes. Each episode spanned a few million years and was characterized by a distinct geochemical signature and geodynamic setting: (i) between 340 and 330 Ma (Visean), high‐K diorites and granitoids within a zone extending parallel the orogen axis, possibly tracing a palaeosuture; (ii) at 310–307 Ma (Westphalian), calc‐alkaline granitoids in the Intra‐Alpine domain; (iii) at 304–295 Ma (Stephanian), subalkaline granitoids in Intra‐Alpine and Pennine domains; and finally (iv) at 280–270 Ma (Permian) granitoids in Pennine, Austroalpine and South‐Alpine domains. The generation and emplacement of granitoid melts in the Variscan crust are suggested to be short‐term pulses that are controlled by extensional processes in the lithosphere such as thermal erosion and relaxation of the lithospheric mantle, and decompressional melting.