ON THE VOLUME AND AGE OF THE KAPKATAS GROUP OF NORTHERN TIEN-SHAN

New data on the structure and age of the Kapkatas Group concern the li thostratigraphic volume of its formations and the first finds of diver se Lower Cambrian fossil assemblages. According to the hyolithid, hyol ithelmintid, and protoconodont assemblages, the uppermost part of the group is correlative with the Botomian stratotype sections of the Sibe rian platform. The studied rock section differs from the Lower Cambria n sequence of tholeiitic basalts recorded in the Northern Tien Shan Ca ledonides in its basalt-andesite-dacite composition and calc-alkaline petrochemical trend.