Neoproterozoic sedimentary basins: stratigraphy, geodynamics and petroleum potential: Guidebook on the post-conf. field trip to the East Sayan Foothills (Novosibirsk, 2-14 Aug., 2011)
(ИНГГ СО РАН)
дата публикации: 2011
Geological research in the Sayan area has been run since about one hundred years ago and was especially active during the construction of the Trans-Siberian railroad. The local geology consists of the sedimentary Karagassy and Oselok Groups upon an metamorphic-igneous basement. The Karagassy Group has been interpreted (Sovetov et al., 2006) as a fill of the Cryogenian Iya-Tumanshet failed rift, and its stratigraphic equivalents are known from the southern Yenisei Ridge but have not been found in the Siberian craton interior. The Oselok Group fills the Sayan Foredeep (a partly inherited structure), and its equivalents are widespread outside the Sayan area making up the Vendian sedimentary cover in the southern Siberian Platform. The upper age constraints of the Karagassy Group are provided by the 740 Ma isotope ages of the intruding Nersa mafic sills and dikes (Gladkochub et al., 2003). The pebbles and cobbles of the Nersa dolerite occur among Early Vendian tillite of the Marnya Formation, the latter being timed as Vendian according to chemostratigraphy and Metazoan fauna, while tillite at its base were correlated with the Varangerian glacial epoch.
страницы: 229 p.