Metasomatic alteration associated with the formation of subvolcanic rocks of the Abagatuysky complex (Nerchinsk ore region, Eastern Transbaikalia)

Within the northeastern edge of the Borschovochny pluton, located in Eastern Transbaikalia, a complex of small intrusions is localized, represented by the subvolcanic bodies of the Early Cretaceous Abagatuysky andesite-dacite complex. These intrusions, along with significant dynamometamorphic (tectonic) transformations, produced the development of metasomatic alteration, united in three large rock associations — propylites, beresites, and argillisites. These metasomatic associations successively replace each other as they move away from the center of heat exposure of intrusions. In addition, each of these groups of metasomatites has its own unique internal mineral zonality, and the most productive of them, on the subject of gold ore mineralization, is the beresite association.