FIRST FINDING OF TRACE FOSSILS IN THE HIG HLY CARBONACEOUS BLACK SHALES OF THE BAZHENOVKA FORMATION IN WEST SIBERIA

The first findings of trace fossils in the higly carbonaceous black sh ales (Corg = 9.58-11.3%) of the Middle Volgian-Lower Berriasian Bazhen ovka Formation of West Siberia are described. The trace fossils severa l centimeters long and no more than 0.5 mm wide are arranged parallel to the bedding plane and slightly meander. Among the modern marine inv ertebrates, representatives of the nematoda class leave most similar b urrow in clayey carbonaceous mud. Being fossils, they are identified a s Zoophycos. The absence of infauna from the higly carbonaceous mud of modern seas (Black and Mediterranean Seas and Norwegian fiords) sugge sts the existence of areas with a low oxygen content below the water/s ediment surface in the deep-water depressions of the Bazhenovka sea bo ttom.