DOI: 10.22184/2227-572X.2020.10.5.386.402

Fe-­Ti eclogites near Ptarmigan mount was studied. The Geochemistry of the main and rare elements shows their similarity to the Salma eclogites of Belomorian province as a whole and have geochemical features with MOR tholeites. In this regard, the mechanism of ocean crust subduction and ultrahigh-­pressure metamorphism in the rocks formation was early proposed. To determine of the age, the Th-­U-Pb isotope system in zircons was studied using LA-ICP-MS. To plan the dating and interpret the obtained ages, zircons were studied using modern methods: optical and electron microscopy, microprobe analysis, 3D laser microscopy, black-and-white (SEM-CL) and color (EPMA-CL (tc)) cathodoluminescence, and Raman spectroscopy. Zircons have a zonal structure – cores with high and shells with very low U and Th contents. The cores of Archean age retain oscillatory magmatic zoning and lack microscopic signs of metamictization. In the Proterozoic shells, cathodoluminescent heterogeneity is observed, which is caused by crystal – chemical factors during a single event of crystallization and mechanical stresses.


Разработка: студия Green Art