ring Summer. These deposits are 1/2 to 2
meters thick in the small valleys, and 2 to 3 meters in the
---- Valleys. Unfavorable to all field works on account of
ground-water and floods, and not thick enough for cave
shelters.

_Silts with some clay and fine sands and locally some fine
gravel and rock debris._ These deposits occur principally on
summits and slopes, and are probably from 1 to 2 meters thick.
Even during dry season (June to September) they retain
moisture and afford rather soft ground. In wet season the
formation is very soft and often muddy. In many places water
occurs along bottom of these deposits. Favorable for trenches,
but which require complete revetment, and ample provision for
drainage, not thick enough for cave shelters; cut and cover
most practical type of shelter.

_Clay at surface with clay shales below._ This deposit occurs
in flats and is usually saturated for a depth of 1 to 2-1/2
meters, during wet season, for most of the year the surface is
soft, but in part dries out in Summer. Deep trenches usually
impossible, and even shallow trenches likely to be filled with
water; defensive works will be principally parapets revetted
on both sides. Cave shelter construction usually
impracticable, unless means be provided for sinking through
saturated surface zone into the dry ground underneath. Cut and
cover usually the most practical type of shelter in this
formation.

_Clay at surface with calcareous clay shale and some thin
limestone layers below._ This formation occurs in low rounded
hills; surface saturated during wet weather, but terrain
permits of natural drainage, and dries out during Summer;
during wet season (October to May) the surface zone is more or
less saturated, and ground may be muddy to a depth of a meter
or more, ground-water level usually within two or three meters
of surface. Trench construction easy, but requires complete
revetment, and ample provision for surface drainage. Cave
shelters can be constructed in this formation where the slope
is sufficient to permit of drainage tunnels. The depth to
ground-water level should always be determined by test shafts
or bore holes in advance of dugout construction.

_Surface formation usually clay 1 to 2 meters in depth; below
this is s