This intrusion consists of several varieties of peralkaline granite emplaced in Carboniferous sedimentary rocks. The western granite is 1.5x3 km, but partly concealed by Quaternary deposits,and composed of aegirine-riebeckite microgranite porphyry which is partly layered, as indicated by concentrations of quartz and K-feldspar and melanocratic phases. At the contact with upper Palaeozoic deposits the rock passes into a cryptocrystalline granite porphyry. The base of the intrusion descends to the west beneath and conformably with the bedding of the country rocks. The thickness of the western part of the sill is estimated at a few hundred meters. The eastern granite is in contact with Carboniferous basalts. It extends over 0.3 x 2 km. and is composed of bluish-grey massive riebeckite-aegirine granite porphyry.