Isotopic composition of hydrogen in magmatic rocks of the Sora porphyry Modeposit (Kuznetsk Alatau)

The Sera magmatic center, formed in the Early-Middle Paleozoic, includes su bduction- (gabbros), collision-, (plutonic granitoids), and rift-related fo rmations. The latter are represented by ore-bearing calc alkalic porphyry a nd bimodal complexes, which formed almost synchronously. Their rocks have e levated delta D values (-78 to -126 parts per thousand) as compared to othe r centers with porphyry Mo-Cu mineralization in the Central-Asian mobile be lt, which is explained by the closer connection of this center with the man tle source at the early stage of development of the belt. The delta D values of calc-alkalic magma responsible for the formation of t he Sera center increased from the subduction stage (-81 parts per thousand) to the collision (-64 parts per thousand) and rifting (-52 parts per thous and) stages, which was probably due to the supply of more deep-seated fluid s at each further stage of magmatism. The initial source of the Devonian bi modal magmatism is the richest in deuterium (-45 parts per thousand). At the subduction and collision stages, the differentiation of calc-alkalic magma was followed by an increase in delta D. On differentiation of the or e-bearing porphyry melt, the delta D value decreased as a result of redistr ibution of deuterium into the fluid which was separated from the melt. The interaction of the separated high-temperature fluid with crystallized rocks led to an increase in delta D in them.