Metamorphism silicate

The oxidation of sulfides preferentially dissolves carbonates, rather than silicates, because the rate of carbonate dissolution is orders of magnitude faster. For example, Haut Glacier d Arolla has a bedrock which is composed of metamorphic silicate rocks. Carbonates and sulfides are present in trace quantities in bedrock samples (0.00-0.58% and <0.005-0.71%, respectively). There are also occasional carbonate veins present in the schistose granite. Despite the bedrock being... 

Jayawardena, U de S. and Izawa, E. 1994. A new chemical index of weathering for metamorphic silicate rocks in tropical regions a study from Sri Lanka. Engineering Geology, 36, 303-310. 

Besshi-type deposits in Sanbagawa metamorphic terrain occur in the Minawa Formation which is composed of basic schist. Sometimes, they are associated with quartz schists. Probably, quartz has been originally formed from hydrothermal solution like siliceous ore in Kuroko deposits. Original rocks of basic schists are basaltic lava and hyaloclastics. Detailed geochemical investigation on the basic schists in the Sanbagawa... 

Presolar stardust discovered to date in meteorites constitute no more than 0.5%o of the total mass of the samples, and one common chemical property is that they are acid resistant. Isotopic heterogeneity could also be present in less refractory phases like silicates, provided parent body metamorphism did not erase the differences. Noble gases are not discussed here because they are depleted by many orders of magnitude relative to the Sun and can be dominated by trace exotic minerals. Nitrogen is not discussed for the same reason. The... 

In contact-metamorphic zones, in association with magnetite and Fe-rich silicates (feldspathoid-bearing igneous rocks)... 

Wall V. I and England R. N. (1979). Zn-Ee spinel-silicate-sulphide reactions as sensors of metamorphic intensive variables and process. Geol Soc. Amer. Abstr. Progr, 11 534. 

Most likely, the chemical system remains closed, as far as the other components in the silicate phases are concerned, as diagenesis or low grade metamorphism becomes more evident. Although there may be transfer of calcium, it seems, from bulk chemical analysis, that there is no systematic increase in potassium nor decrease in sodium content of argillaceous sediments. The transfer of Na and K is between the two size fractions—clay and coarse fraction—or between phyllosilicates and tectosilicates. Albitization of argillaceous rocks should be a common phenomenon where mixed layered phases are predominant in clay assemblages and especially evident in the illite-chlorite zone. 

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