New isotopic data on the protolith age and evolutionary stages of the Chupa Formation, Belomorian Belt

Authors
Bibikova, EV Glebovitskii, VA Claesson, S Miller, YV Kirnozova, TI Myskova, TA L'vov, AB Makarov, VA
Citation
Ev. Bibikova et al., New isotopic data on the protolith age and evolutionary stages of the Chupa Formation, Belomorian Belt, GEOCHEM INT, 39, 2001, pp. S12-S17
Citations number
13
Categorie Soggetti
Earth Sciences
Journal title
GEOCHEMISTRY INTERNATIONAL
ISSN journal
00167029 → ACNP
Volume
39
Year of publication
2001
Supplement
1
Pages
S12 - S17
Database
ISI
SICI code
0016-7029(2001)39:<S12:NIDOTP>2.0.ZU;2-H
Abstract
New isotopic-geochemical data were obtained in order to date the distinct e volutionary stages of the Chupa Formation in the Belomorian Mobile Belt. Re ference U-Pb and Sm-Nd isotopic data are reported for relict rock volumes, which were the least altered during several migmatization stages. Our resul ts indicate that the initial volcanisin processes took place at 2850 +/- 30 Ma, and high-grade metamorphism is dated at 2820 +/- 20 and 2720 +/- 20 Ma . The age of the protolith of the metasediments, determined using the cores of detrital zircon grains on a secondary-ion mass spectrometer, lies withi n the range of 2900-3000 Ma and is consistent with the whole-rock Sm-Nd age values.