Tuluyul'

This small alkaline intrusion is confined to the contact zone of lower Cambrian limestones and upper Cambrian-lower Ordovician granitoids. The intrusion is predominantly composed of alkaline gabbro, theralite and feldspathic ijolite but nepheline syenite also outcrops in the eastern and northern parts of the intrusion and is partly replaced by liebenerite and altered to liebenerite syenite of feldspar, liebenerite (30%), albite and relicts of coloured minerals. Dykes of various compositions are known including diabase, lamprophyre, nepheline syenite and microsyenite.