Trace fossils from Upper Pleistocene varved clays S of Kaunas, Lithuania

Relatively common trace fossils Gordia, Helminthoidichnites, Galaciichnium, and rare Cochlichnus, Warvichnium, and curved ridges occur in the Upper Pleistocene varve clays at Balbieriškis and Girininkai, S of Kaunas. They occur in single laminae every one or two decimetre in clayey lamina packages and are absent in laminae rich in carbonates. It is not clear whether such a distribution resulted from rare occurrences of proper preservational conditions or from incidental colonization of the lake floor. The trace fossils are typical of the Mermia ichnofacies. The Cursichnia ichnocoenosis represented by Glaciichnium and Warvichnium and the Gordia ichnocoenosis (new one) represented by Gordia and Helminthoidichnites are distinguished. Their dominance suggests that the study deposits accumulated in the transition from metalimnion to hypolimnion.