Within separate formations, we have revealed a distinct positive correlation between δ18O and SiO2?, which is typical for thermodynamically ordered metamorphic rocks composed of minerals in isotopic equilibrium.
The provenances were composed of volcanic and volcanosedimentary rocks (Uda-Murgal island arc and Okhotsk-Chukotka volcanic belt) and granitic-metamorphic rocks (the mature Asian continental margin).
Some sediments were formed as the result of the erosion of proximal volcanic complexes, whereas other sediments were related to the erosion of metamorphic rocks on the distal continental land.
Melt inclusions in rock-forming and accessory minerals of high-grade metamorphic rocks: Indicators of the nature and formation c
The Paleozoic age of high-pressure metamorphic rocks in the Dakhov Salient, northwestern Caucasus: Results of U-Pb geochronologi
There are four types of pyrite, which are contained in the light metamorphosed rocks (limestone, siltstone), altered-mineralized rocks (chlorite-schist, altered albite-granite, mineralized phyllite), quartz veins and carbonatite veinlets.
Reactions between sulfur vapor and silicate minerals produce sulfides and oxides commonly observed in metamorphosed rocks.
Pyrite-silicate reactions and hydrothermal exhalations have been suggested previously to account for pyrrhotite-enriched horizons in regionally metamorphosed rocks.
They do occur within metamorphosed rocks that attained temperatures sufficiently high (upper amphibolite facies) for the formation of homogeneous Al-Cr-Fe3+-Ti spinel phases with compositions not matched in slowly cooled igneous rocks.
Several types of anhydrite-bearing rocks have been found in the amphibolite-facies metamorphosed rocks at the north-eastern margin of the Moldanubian Zone.