GEOCHEMISTRY OF ROCKS IN THE GOLOUSTNAYA BLOCK IN THE SOUTHERN FRAMING OF THE SIBERIAN PLATFORM

Abstract

The first geochemical data were obtained on rock of the Goloustnaya block in the southern framing of the Siberian Platform. It was established that the early (relict) metavolcanic rocks display geochemical features characteristic of analogous rocks from island-arc environments and active continental margins. The leucocratic granites, which account for as much as 80% of the exposed block area, are principally different geochemically from the seemingly similar medium- and fine-grained granites of the second phase in the Primorskii Complex. The granites of the block were determined to be geochemically similar to one of the granitoid types of Priol'khon'e, which had been formed under elevated pressures in the so-called Chernorudskaya zone. It is suggested that the Goloustnaya block was a tectonic slab in the imbricated structure of the southern surroundings of the Siberian Platform. This structure resulted from Caledonian collisional events in the area.