• Five to seven meters of indurated angular debris of green tuffs of the Kurgan

•formation are followed by an ~30-meter thick well-indurated diamictite member. This member consists of chaotically distributed clasts that are found among small angular debris and sand in a green clayish matrix (Fig. 3A). Some of the clasts are typical dropstones with a keel or undulating surface. The rear parts of dropstones are very uneven and show no rounding and sets of scratches and minor troughs are well developed on other surfaces (Fig. 3B). An upper clastic bed, about 10–15 m thick, consists of chaotically distributed angular clasts (2–5 cm in size) that account for ~20% of rock volume. This upper clastic bed is followed by a 30–40 cm thick transitional zone from tillites to pink cap dolomites. The zone includes a thin layer of green slate with lenses of sandy dolomite and finely laminated red slates with a bed of massive fine-grained pink dolomite at the top. The main part of cap-dolomite is represented by dense porcelain-like layered rock, sometimes with a wavy pattern that may be layered

•stromatolites. In this location, the cap dolomite is 1 to 3 mthick and is followed, with a hiatus, by a brownish fine-grained dolomite.

• siliclastic beds. These siliclastic beds contain ‘elephant-skin’

•wrinkle structures that are thought to represent trace remains of microbial mats into which Ediacara organisms could attach their holdfasts. This oxygen-poor

•environment also enhanced preservation potential for Ediacara fossils