The muck is reworked silt with intermixed organic material. The muck was deposited unfrozen, and decay of the organic material was free to take place. It is believed that the muck may have gone through several cycles of freezing and thawing, decay taking place in the thawed stage. Due to sublimation of the ice, dust is present everywhere, a thick layer is on the floor of the tunnel. The sublimation has also made the ice wedges retreat.
Frost crystals cover large areas of the ceiling.
This is a function of bringing moisture in from the outside. The gravels exhibit spectacular creep and subsidence. This can be observed by the poles and beams installed in the chamber excavated in the gravel. The creep rate is temperature dependent. During excavation of the gravels, temperatures of 0 degrees C to - 0.5 degrees C were encountered.