Home – Home – Jornals – Russian Geology and Geophysics 2001 number 9

We describe stromatolites and oncolites found in Mesozoic strata of the West Siberian Plate. They occur in the Upper Jurassic terrigenous-carbonate deposits of the upper member of the Abalak Formation in the west of the plate. This formation is an analog of the Georgievka Formation widespread in the region. The stromatolites are small-columnar, with the columns 1.5-2.5 cm wide and up to 4.5 cm high. The oncolites reach 4-5 cm in size. Along with stromatolites and oncolites, there are also stromatolite concretions measuring up to 10 cm and microstromatolitic and microoncolitic bodies as small as few millimeters.