These large (hammer is 20cm long) vertical structures are found in lacustrine sediments (homogeneous fine-grained sand with dropstones, left of picture) of the Alpine last glacial maximum.
They show a sharp contact to the surrounding sediments, seem to be layered vertically - note however that the longest axis of the pebbles seem to be oriented horizontally - origin: unknown.
They show a sharp contact to the surrounding sediments, seem to be layered vertically - note however that the longest axis of the pebbles seem to be oriented horizontally - origin: unknown.
