NEW MATERIALS ON GEOLOGY OF SOUTHERN PART OF KURATINSKY TROUGH OF THE CENTRAL ALTAY

O. M. Popova, V. I. Krupchatnikov

On base of the new material analysis, got at GDP-200 on map M-45-VIII sheet, is offered new dismemberment Middle-Late Devonian volcanogenic and sedimentary formations of Ursul series (Group), widespread in southern part of Kuratinsky trough of the Central Altay. The different standpoint on composition and age of formations of this series are considered. Change the age, borders and composition of the formations are motivated. On the basis performed studies are permitted new stratigraphic subdivision of Late Devonian age – Kuladin formation. On base of the new data about sedimentary-volcanogenic composition of the formation instead of terrigenous composition, fixed in «Stratigraphic dictionary» (1975), new subdivision is entered instead of earlier selected Bichiktubom formation. Besides, the borders of subdivision with laying under Tuekta formation and overlaying Boguchin formation are revised, they are fixed on appearance (lower) and on disappearance (upper) effusive rocks in the geological section. Litological, fasies and paleontological data of the formation is given, it is shown the area of the spreading. Supporting point geological section of the Kuladin formation in the watershed of the Karakol river is considered. The paper presents petrochemical and geochemical data volcanogenic rocks of Kuladin formation, comparative analysis with Middle Devonian acidic volcanic rocks of Kuratin formation and dolerites of Ursul complex having alike age. On geochemical parameters the magmatic rocks of the Kuladin formation are compared with intraplate magmatic rocks having rare-element and rare-earth element specialization.

Key words: Ursul series, Kuladin formation, sedimentary-volcanogenic formations, effusive rocks, Kuratinsky trough, Central Altay.

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