On reasons of specific composition of the Keivy domain rocks (the Kola Peninsula)
Journal Title: Вестник МГТУ - Year 2017, Vol 20, Issue 1
Abstract
The Keivy domaindiffers from the other structures of the Kola region by the specific composition of the metamorphic complexes, the presence of the oldest for the region alkaline granites and gabbroanorthosites associated with them as well as by the presence of unique mineral deposits. The previous studies of the Keivy structure showed that within this structure there are metasedimentary formations that differ from both Early Precambrian metasedimentary rock associations of the Kola region and Phanerozoic sedimentary complexes in the content of titanium and the ratio Al2O3/SiO2. The present study confirms the correctness of this conclusion. The authors have attempted the search of the generalized indicator (trend) describing the nature of changes in the chemical composition of rocks in the transition from Low-Ti to High-Ti varieties of rocks (with simultaneous increase in the ratio Al2O3/SiO2). To solve this problem the method of search of differences in the specified number of sets has been used with the partial order relation introduced by the researcher. The formations of the same type and age, namely metapelites of the Chervurtskaya suite of the Keivy series, have been chosen as the informational basis. Such indicator has been found. It describes the process which besides a significant titanium input was accompanied by a simultaneous increase in the content of CaO and decrease in the content of Al2O3, ΣFe, and Na2O. It must be emphasized that the obtained trend is not related to the supergene processes characterized by the similar behavior of titanium with aluminum and iron which is especially clearly exhibited in the formation of crusts of weathering. The location on this generalized indicator of the points of rock compositions of all strata of the geological section of the Keivy domain taken far or close to alkaline granites corresponds to the position of less or more titaniferous rocks, thus confirming the assumption of a metasomatic alteration of the latter. The fact that all the metasedimentary Keivy formations are subjected to metasomatic alteration most probably related to the Archean complexes of alkaline granites, which is confirmed by direct geological observations of the relationships of the Lebyazhinskiye and Chervurtskiye rock complexes with alkaline granites, allows us to speak about their Archean age.
Authors and Affiliations
N. E. Kozlov, E. N. Fomina, E. V. Martynov, N. O. Sorokhtin, T. S. Marchuk
Structure of settlements of Macoma balthica in the southern knee of the Kola Bay
The study of seasonal dynamics of size-mass structure of Macoma balthica settlements has been investigated on the littoral zone of the southern part of the Kola Bay. Age structure has been calculated; data on the density...
Numerical modelling of fragmented mined rock flow during ore drawing using the ROCKY DEM programme
he results of analyzing the existing methods and algorithms of predicting losses and dilution of ore at its release through the inlets after the explosive crushing of the rock mass have been presented. It has been shown...
Development of new types of precooked meat products – cutlets for older people
The results of research of chopped semi-finished products (cutlets) developed on the basis of meat-seed minced meat with the addition of wheat germ, flour of wheaten whole meal, and representing value for people of elder...
Growth of Pedicularis palustris L. (Orobanchaceae) in the grassy fens of the Murmansk Region
The main stages of ontogenetic growth of Pedicularis palustris (Orobanchaceae) in the multi-species communities of grassy fens in the central part of the Murmansk region (in the vicinity of the town of Apatity) have been...
Mannitol content in different parts of Fucus vesiculosus thallus from the Barents Sea in different seasons
The data on the mannitol content in different parts of the brown algae F. vesiculosus thallus from the Barents Sea have been obtained for the first time in different seasons. Seaweed for research was collected in the Bel...