Raman spectra of impact zircons in the Jarva-varaka layered massif (the Monchegorsk ore region, the Kola Peninsula)
Journal Title: Вестник МГТУ - Year 2017, Vol 20, Issue 1
Abstract
Zircon crystals from granophyre norites of the Jarva-varaka massif of the Monchegorsk ore region (the Kola Peninsula) have been studied by means of back-scattered electron (BSE) imaging and Raman spectroscopy. The Jarva-varaka massif according to geological and geochemical data has been compared with the Sudbury structure, for which an impact origin is assumed. Zircon study is stipulated by zircon ability to keep signs of shock metamorphism even under granulite-facies conditions, thus it can be used for identification of ancient impact structures. BSE images reveal complicated internal texture – darker central domains (cores) and light rims without texture. Mineral inclusions in zircon are represented by sillimanite and plagioclase which indicates that the studied zircon grains were inherited from the host aluminous gneisses. Zircon crystals show variation of Raman spectra from the core of crystals with typical zircon Raman pattern to complete absence of spectral bands in the marginal parts and rims. Mineral inclusions in zircon rims also have no Raman spectra. Such patterns may be associated with the transformation of crystalline zircon (and mineral inclusions in it) to diaplectic glass under the influence of shock metamorphism, core domains were screened by rims and thus preserved their structure. The received data suggest the participation of the meteorite impact in the formation of the Jarva-varaka massif that requires further investigation.
Authors and Affiliations
T. V. Kaulina, L. I. Nerovich, V. N. Bocharov, L. M. Lyalina, V. L. Il'chenko, E. L. Kunakkuzin, I. A. Kasatkin
Keywords
Related Articles
- EP ID EP216697
- DOI 10.21443/1560-9278-2017-20-1/1-72-82
- Views 173
- Downloads 0
Estimate of the trophic status ofsubarctic Imandra Lake
The object of study isImandra Lake – the largest reservoir of the Murmansk region. The lake is being influenced by the long-term and multi-factorial activities of mining and ore processing industries, air pollution and e...
Effect of extraction technology on antioxidant activity of black chokeberry Aronia melanocarpa, cranberries Vaccinium vitis-idaéa, blueberries Vaccinium myrtillus, raspberries Rubus idaeus, cherries Prunus subg. cérasus, black currant Ribes nigrum
Foods rich in antioxidants and antioxidant activity reduce the risk of many diseases. To solve the urgent task of creating an optimal technology for extracting a complex of substances with antioxidant action from fruits...
Comparative analysis of the quality of drinking tap water in some areas of the Murmansk region
The present work describes the microbiological research of drinking tap water quality of some settlements in the Murmansk region. The samples of drinking tap water have been selected and the microbiological indicators of...
Grey seals: Morphometric parameters of erythrocytes
The first 3–4 months of postnatal ontogenesis of true seals are characterized by the most significant changes in the cellular composition of the blood, which is associated with active processes of formation of bone marro...
Development and functioning of microorganisms in concentration cycles of sulfide copper-nickel and non-sulfide apatite-nepheline ores
The number and trophic diversity of bacteria in flotation samples of apatite-nepheline and sulfide copper-nickel ores at the concentration plants of JSC "Apatite" and Kola Mining and Metallurgical Company have been deter...