REE distribution in some layered migmatites

constraints on their petrogenesis

authored by: Wilhelm Johannes, Francois Holtz, P. Möller
Abstract: The REE distributions in mesosomes, neosomes, leucosomes and melanosomes of four layered migmatites have been investigated. In one example (Arvika migmatites) the REE patterns in adjacent paragneisses, the presumed parent rock of the migmatites, were also determined. REE patterns of neosomes and mesosomes of Arvika migmatites are similar to the finegrained layers and coarse-grained layers, respectively, observed in the adjacent paragneiss. This is in agreement with the layer-by-layer paragneiss-migmatite transformation model. The REE patterns of mesosomes and neosomes indicate that these lithologies may have been closed systems (for REE) during the formation of the migmatites. No indication of metasomatic reactions, melt segregation or injection could be detected. Within the neosomes, leucosomes are depleted and melanosomes enriched in REE contents. This is interpreted to be due to separation and concentration of accessory minerals (monazite, epidote, allanite, zircon, sphene, apatite, garnet) into the melanosomes. The behaviour of accessory minerals during migmatite formation is closely allied to that of biotite, which is also concentrated in the melanosomes.
Organisation(s): Institute of Mineralogy
External Organisation(s): Helmholtz Centre Potsdam - German Research Centre for Geosciences (GFZ)
Centre national de la recherche scientifique (CNRS)
Type: Article
Journal: Lithos
Volume: 35
Pages: 139-152
No. of pages: 14
ISSN: 0024-4937
Publication date: 06.1995
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Geology, Geochemistry and Petrology
Electronic version(s): https://doi.org/10.1016/0024-4937(95)00003-X (Access: Unknown)

BibTeX

@article{1adbdff8eaf64997ae2b60de9a064181,
title = "REE distribution in some layered migmatites: constraints on their petrogenesis",
abstract = "The REE distributions in mesosomes, neosomes, leucosomes and melanosomes of four layered migmatites have been investigated. In one example (Arvika migmatites) the REE patterns in adjacent paragneisses, the presumed parent rock of the migmatites, were also determined. REE patterns of neosomes and mesosomes of Arvika migmatites are similar to the finegrained layers and coarse-grained layers, respectively, observed in the adjacent paragneiss. This is in agreement with the layer-by-layer paragneiss-migmatite transformation model. The REE patterns of mesosomes and neosomes indicate that these lithologies may have been closed systems (for REE) during the formation of the migmatites. No indication of metasomatic reactions, melt segregation or injection could be detected. Within the neosomes, leucosomes are depleted and melanosomes enriched in REE contents. This is interpreted to be due to separation and concentration of accessory minerals (monazite, epidote, allanite, zircon, sphene, apatite, garnet) into the melanosomes. The behaviour of accessory minerals during migmatite formation is closely allied to that of biotite, which is also concentrated in the melanosomes.",
author = "Wilhelm Johannes and Francois Holtz and P. M{\"o}ller",
note = "Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",
year = "1995",
month = jun,
doi = "10.1016/0024-4937(95)00003-X",
language = "English",
volume = "35",
pages = "139--152",
journal = "Lithos",
issn = "0024-4937",
publisher = "Elsevier",
number = "3-4",
}