CARBON AND HEAVY NOBLE-GAS ISOTOPES IN TH E METAMORPHIC FLUIDS

Basing on the data on the correlation of carbon and non-radiogenic nob le gas isotopes in the mantle reservoirs a new genetic criteria of the metamorphic fluid is presented. Modeling calculations indicate that t he C/Ar-36 ratio of the metamorphic fluids in the continental crust mu st be below 10(10) the latter known as a mantle value. The study of na tural samples such as high carbon bearing sedimentary rocks, Precambri an sandstones, and amfibolite facies rocks of the Notozero complex (No rthern Karelia) has provided the experimental confirmation of the calc ulated parameters of the crustral metamorphic fluids. The causes and r esults of carbon and noble gas isotopic fractionation in the fluid pha se in the process of vlatile capture from natural waters and within th e subsequent diagenesis is studied.