Arumberia and other microbial mats from the Neoproterozoic-Cambrian strata of East Siberia

We present and describe several forms of organosedimentary structures observed in Neoproterozoic and Cambrian sandstones exposed on the Irkineeva Uplift of East Siberia. One of the structures belongs to the problematic fossil Arumberia Glaessner and Walter. The Arumberia-bearing sandstones were deposited in a tidal influenced shallow water environment and belong to the Ostrov Formation. On the basis of world- wide occurrence of Arumberia, an Ediacaran age is suggested for the Ostrov Formation sandstones.