Burrstone,
Dirt bed,
black mould,
and pebbles.
Calcareous slate
o f fresh water
formation.
Fig- g
Dowei'
Purbeck
beds.
Temporary
dry land.
Marine
formation.
Section of the Dirt-bed in the Isle of Portland, shewing the subterranean remains
of an ancient Forest. De la Beche.
Circular ridges and depressions on the Burrstone, in the I. of Portland, round an erect
stump of a tree, four fee t high. Sketched by Professor Henslow, 1832.
Fig. 3.
Lower Purbeck beds
composed of calcareous
slate of freshwater
formation.
Soft burrstone.
Ancient forest in the
dirt bed.
Portland stone of
marine formation.
Section of the Cliff east of Lulworth Cove, Dorset. Buckland.
