PROBLEM OF WATER IN INDEPENDENT ANORTHOSITES

Abstract

The results of our thermobarogeochemical study of rocks of the anorthosite complex discussed here allow us not only to estimate the parameters of the fluid directly in inclusions from different minerals, but also to trace its evolution throughout the process of development of this complex. The fluid and solid inclusions studied were recovered from minerals of the Dzhugdzhur anorthosite batholith, with a Rb-Sr isotope age of 2.93 ± 0.1 b.y. This batholith, one of the largest and most typical of all known independent anorthosite plutons, lies among rocks of the Early Archean granulite complex in the eastern part of the Stanovoy folded system. Our thermobarogeochemical data are not inconsistent with the assumption that a highly reducing fluid consisting essentially of hydrogen participates in the anorthosite-forming process.