Rare earth spectra were used to subdivide Archean komatiites from Baltic Shield into 4 groups:
1. komatiites showing a chondritic nonfractionated REE distribution:{(La/Sm)n=0.8-1.1, (Gd/Yb)n=0.9-1.2, (Ce/Yb)n=0.9-1.1} Palaselga,Ura-Guba, Polmos-Poros, Kamennoozero;
2. LREE-depleted komatiites:{(La/Sm)n=0.4-0.7, (Gd/Yb)n=0.89-1.4, (Ce/Yb)n=0.6-0.8} Kuhmo (Finland);
3. LREE-enriched komatiites:{(La/Sm)n=1.4-1.6, (Gd/Yb)n=1.1-1.4, (Ce/Yb)n=1.1-1.2} Sovdozero, Hautavaara;
Proterozoic Windy Belt komatiites do not differ substantially in major petrogenic oxides from Archean komatiites and represent the same Al-undepleted type, but they are more intensely enriched in LREE and are higher at a general level than Archean komatiites.
Sm-Nd isotopic study of the Vedlozero-Segozero greenstone belt, Koikary and Palaselga domains.
Komatiites of the Baltic Shield:
Kola peninsula:
1-Ura-Guba
2-Polmos-Poros
North Karelia:
3-Hizovaara
4-Kostomukcha
Cenral Karelia:
5-Sovdozero
6-Hautavaara
7-Palaselga
1. Introduction
2. Geology
3. Layered flows
4. Structures
5. Petrography
6. Geochemistry
7. Mantle sources
8. References
9. Researcher (Sergei Svetov)