Search
Results:
Vol. 1 (1998 year), No. 3
Kozlov N.E., Kozlova N.E.
On Genesis of Garnet Plagiogranitoids of the Lapland Granulite Belt
On the basis of geological, geochemical and petrographic data the comparison of plagiogranitoids of the northern and north-west part of the Lapland Granulite Belt with acid granulites has been carried out. The conclusion of sintectonic intrusion of rocks initial for garnet plagiogranitoids into rocks undergone metamorphism of granulite facies has been made. Petrogeochemical data assume an opportunity of plagiogranitoid substance formation as a result of diatexis from the substratum corresponding to acid granulites by its structure. Presence of granulite facies rocks in the plagiogranitoids assumes two stages of granulite metamorphism which had been broken off in time by a stage of plagiogranitoid intrusion. The data of vibroseismic sounding show loss of stratification in the northern part of the belt connected with palingenesis processes.
(in Russian, стр.10, fig. 4, tables. 5, ref 15, MS Word 95, MS Word 95 3020 Kb)
Vol. 12 (2009 year), No. 3
Sorokhtin N.O., Kozlov N.E., Martynov E.V., Kozlova N.E.
The Late Archaean comatiites: Certain aspects of ore content
Boninites are characterised by a great range of variety and they cannot be practically compared with igneous rocks like picrites, picrite-basalts, basalts, andesites, dacite, and rhyolites. This feature is conditioned by the presence of non-equilibrium phases: quarts-normative matrix and olivine impregnation. Abundance ratio and composition of non-equilibrium phases may be different, and that causes the variety of boninites. The boninite magmas were probably generated by the process of fractional crystallisation of high-magnesium picrite and picrite-basalt melts in subvolcanic conditions. It is necessary for the formation of boninites magmas that the eruption of magma was occurred at a definite stage of crystallisation before olivine separation.
(in Russian, стр.9, fig. 6, tables. 3, ref 20, Adobe PDF, Adobe PDF 0 Kb)