THE KOSTOMUKSHA GREENSTONE-BELT, NW-BALTIC SHIELD - REMNANT OF A LATEARCHEAN OCEANIC PLATEAU

Authors
PUCHTEL IS HOFMANN AW JOCHUM KP MEZGER K SHCHIPANSKY AA SAMSONOV AV
Citation
Is. Puchtel et al., THE KOSTOMUKSHA GREENSTONE-BELT, NW-BALTIC SHIELD - REMNANT OF A LATEARCHEAN OCEANIC PLATEAU, Terra nova, 9(2), 1997, pp. 87-90
Citations number
27
Categorie Soggetti
Geosciences, Interdisciplinary
Journal title
Terra nova → ACNP
ISSN journal
09544879
Volume
9
Issue
2
Year of publication
1997
Pages
87 - 90
Database
ISI
SICI code
0954-4879(1997)9:2<87:TKGNS->2.0.ZU;2-G
Abstract
The Kostomuksha greenstone belt consists of two lithotectonic terranes , one mafic igneous and the other sedimentary, separated by a major sh ear zone, The former contains submarine 2.8 Gyr old komatiite-basalt l avas and volcaniclastic lithologies with trace element and isotopic co mpositions resembling those of recent oceanic flood basalts [epsilon N d(T) = + 2.8, mu(1) = 8.73 (Nb/Th)N = 1.5-2.1 (Nb/La)N = 1.0-1.5], We suggest that the mafic terrane is a remnant of the upper crustal part of an Archaean oceanic plateau derived from partial melting of a mantl e plume head.