This locus is only 50 cm long. The reason for such short locus is the increasing height of the soft bedrock below the south or right tunnel wall and we don’t want to expose too long a stretch of unstable wall in one time.
After each 50 cm we will decide if a horizontal support is needed. The horizontal supports are secondary used as new steps, on the high side the open space is filled with soil or small stones that create a nice level step. At the same time this fill prevents the original stones to fall out of place.
Top of the soil from the ground is about 40 cm high. This is divided arbitrary in a top 20 cm and a bottom 20 cm.
The locus contains the top fill layer in the tunnel fill, with many snail remains.
