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 169
- Downloads 0
Recovery of waste and side products of apatite-nepheline and eudialyte ores processing in manufacture of heat-insulating foam glassy-crystalline materials
Overburden and dressing tailings accumulated in the Murmansk region in impressive volumes represent serious challenges of both economic and ecological character. Maintenance of overburden dumps and dressing tailings invo...
Improving the process of grinding food products
There are a large number of studies on the grinding of various types of food raw materials, however, today there is no comprehensive approach to justifying the influence of the design and operational parameters of the gr...
Modelling cyclic reverse movements of the vessel using modified Lammeren's curves of screw action
In our national practice, the screw action curves are traditionally used either for positive values of the screw speed n and the vessel's velocity v, or when one of these characteristics of the movement is negative. Cons...
Macroalgae's flora of the Kola Bay (the Barents Sea)
The Kola Bay is the most developed part of the Barents Sea. Benthic phytocenoses of its southern part are well studied, and the Northern ones have almost no modern descriptions. Flora of the Kola Bay has not been revised...
Reactor units for power supply to the Russian Arctic regions: Priority assessment of nuclear energy sources
Under conditions of competitiveness of small nuclear power plants (SNPP) and feasibility of their use to supply power to remote and inaccessible regions the competition occurs between nuclear energy sources, which is cau...