Soil sections

We have a soil section in a glass case. The sample has a height of
63cm, the width is 59.5cm and it is 2.5cm deep.  The section has 12
layers of different soil types.  The whole section has subsided so
that it now sits about 10cm below its original level.  There are
many 'holes' caused by uneven subsidence of the layers.  Some of the
layers were obviously quite moist when enclosed in the case and have
dried differently.  One layer has hardened, with the result that
there are large gaps between the hardened layer and the sandy layers
beneath.  The hardened layer has also cracked and the sides may
eventually fall into the gaps below.  Other layers have remained
moist for some time and have left muddy smudges along the glass as
they have shifted downwards.  This has obscured other soil layers.
Can anyone suggest a treatment that would stabilise the section and
prevent any further shifting of the layers?

Vanessa Roth
Objects Conservator
Artlab Australia

                                  ***
                  Conservation DistList Instance 9:68
                  Distributed: Tuesday, April 2, 1996
                        Message Id: cdl-9-68-005
                                  ***