THE 40AR-39AR DATING OF METASOMATIC ROCKS IN DEEP FAULT ZONES OF THE MARGINAL SUTURE OF THE SIBERIAN PLATFORM

Abstract

Metasomatites localized in deep fault zones and lacking genetic relations to specific igneous rock bodies are interesting for geochemical characterization of endogenic fluid systems. Quartz-muscovite, alkaline, and magnesian-calcic metasomatites are widespread in faults related to the marginal suture of the Siberian Platform, e.g., in the Primorskii Fault Zone (western Baikal region) and southeastern segment of the Main Sayan Fault Zone (Sayan region). The 40Ar-39Ar dating of rock-forming minerals in altered rocks of various geochemical types was undertaken in order to provide insights into their chronological sequence.