Figure 6. Scheme showing the Vendian foreland basin of the Siberian
cratonic margin and distribution of glacial deposits within it.
(A) Cis-Sayan foredeep. Post-Vendian deposits: 1 - Lower Jurassic, 2 - Lower Carboniferous,
3 - Middle Devonian, 4 - Lower Ordovician, 5 - Lower
Cambrian. Lithostratigraphic units of Vendian deposits:
6 - Ust-Tagul Formation, 7 - Oselkovaya Group (Marnya,
Uda, and Aisa Formations). Pre-Vendian deposits: 8 - Karagas
Group, Early Neo-Proterozoic, 9 - metamorphic and igneous
basement assemblages. Faults: 10 - post-Vendian, 11 - marginal
tectonic suture of the Siberian craton.
(B) Marnya segment of the Cis-Sayan foredeep. Pre-Vendian rocks: 1 - metamorphic and
igneous basement, 2 - Karagas Group. Lower stratigraphic units of
the Vendian (Oselkovaya) molasse: 3 - Marnya Formation and lower
portion of the Uda Formation, 4 - upper portion of the Uda
Formation. Finds of tillites and traces of nonskeletal faunas:
5 - diamictites (tillites) at the base of the Ulyakh Member,
6 - faceted boulder breccias at the base of the
Plitninskaya Member, 7 - traces of vital activity of nonskeletal
Metazoa (ichnofossils), 8 - faults, principal and subsidiary.
(C) Assemblage of deposits of the lower portion of the Vendian (Oselkovaya) molasse.
1 - diamictites (tillites), glaciofluvial faceted boulder
breccias and eolian sandstones, lacustrine siltstones and
bituminous shales. Sandstones of marine environments:
2 - nearshore, 3 - storm-dominated, 4 - hurricane
current-dominated. Gravelstones, sandstones, and siltstones of
terrestrial and transitional environments: 5 - fluvial
(cratonic), 6 - deltaic, 7 - fluvial (orogenic), 8 - fluvial,
recording main stages of fluvial plain progradation. Limestones
and dolomites of (9) microphytolith bars and stromatolite
buildups, (10) distal shelf silt zone, and (11) postglacial (cap)
laminated, bioherm, and of sand waves; 12 - units of the Karagas
Group and depth of erosion in molasse. Stratigraphic position of
(13) tillites and (14) finds of ichnofossils and molds of
nonskeletal Metazoa. Three eustatic cycles (arrows) with intervals
of deposits of sea-level lowstand, rapid marine transgression, and
sea-level highstand.