Geochemistry of rocks in the Goloustnaya block in the southern framing of the Siberian Platform

The first geochemical data were obtained on rock of the Goloustnaya block i n the southern framing of the Siberian Platform. It was established that th e early (relict) metavolcanic rocks display geochemical features characteri stic of analogous rocks from island-are 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 seemi ngly similar medium- and fine-grained granites of the second phase in the P rimorskii Complex. The granites of the block were determined to be geochemi cally 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 i s suggested that the Goloustnaya block was a tectonic slab in the imbricate d structure of the southern surroundingsof the Siberian Platform. This stru cture resulted from Caledonian collisional events in the area.