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Date submitted2019-09-04
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Date accepted2019-12-25
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Date published2020-04-24
Composition of spherules and lower mantle minerals, isotopic and geochemical characteristics of zircon from volcaniclastic facies of the Mriya lamproite pipe
The article presents the results of studying the rocks of the pyroclastic facies of the Mriya lamproite pipe, located on the Priazovsky block of the Ukrainian shield. In them the rock's mineral composition includes a complex of exotic mineral particles formed under extreme reduction mantle conditions: silicate spherules, particles of native metals and intermetallic alloys, oxygen-free minerals such as diamond, qusongite (WC), and osbornite (TiN). The aim of the research is to establish the genesis of volcaniclastic rocks and to develop ideas of the highly deoxidized mantle mineral association (HRMMA), as well as to conduct an isotopic and geochemical study of zircon. As a result, groups of minerals from different sources are identified in the heavy fraction: HRMMA can be attributed to the juvenile magmatic component of volcaniclastic rocks; a group of minerals and xenoliths that can be interpreted as xenogenic random material associated with mantle nodules destruction (hornblendite, olivinite and dunite xenoliths), intrusive lamproites (tremolite-hornblende) and crystalline basement rocks (zircon, hornblende, epidote, and granitic xenoliths). The studied volcaniclastic rocks can be defined as intrusive pyroclastic facies (tuffisites) formed after the lamproites intrusion. Obviously, the HRMMA components formed under extreme reducing conditions at high temperatures, which are characteristic of the transition core-mantle zone. Thus, we believe that the formation of primary metal-silicate HRMMA melts is associated with the transition zone D".
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Date submitted1908-03-02
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Date accepted1908-05-24
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Date published1908-09-01
Crystals of the Mineralogical Museum
- Authors:
- Ye. S. Fedorov
Natural crystals are the most difficult object for the method of crystal-chemical analysis, and I must admit that my attempt to give the correct setting to all minerals turned out to be imperfect in many points. But it was precisely this imperfection that prompted the further development of criteria for correct installation, and pointed to the need to reconsider and individually study the crystals of many minerals.