GRAPTOLITES FROM THE UPPER ORDOVICIAN SECTION «VERKHNYAYA KARASU» IN THE CENTRAL PART OF GORNY ALTAI

Abstract

Taxonomic complex of graptolites from the «Verkhnyaya Karasu» section have been studied. This section is located in the central part of Gorny Altai Mountains. The section covers a large stratigraphic interval: from upper Ordovician (Sandbian Stage) to Middle Silurian (Telychian Stage). For the Ordovician, the Bugryshikha, Khankhara and Tekhten' formations are distinguished. For the Silurian, the Vtorye Utyosy, Syrovaty, Polaty, Chesnokovka and Chesnokovka formations are distinguished. Previously, in this section no graptolites were found in the upper part of the Bugryshikha formation. There is a large and diverse complex of taxa collected in 2020. The graptolites assemblage from the upper part of the Bugryshikha formation consists of Reteograptus uniformis Mu et Zhang, Reteograptus geinitzianus Hall, Eoglyptograptus euglyphus Mitchell, Orthograptus apiculatus Elles et Wood, Orthograptus whitfieldi (Hall), Rectograptus truncatus (Lapworth), Rectograptus ex.gr. truncatus (Lapworth), Hustedograptus sp., Callograptus sp.