folding are important in determining the forms of cliff profiles. To
a lesser extent, the direction in which the cracks andjoints lie in other
types of rocks, such as granite are also of significant in their cliff profiles.
Horizon tal bedding (C), as in the chalk cliffs of the Seven Sisters
in Sussex, enables the formation of high vertical cliffs that lose blocks
from their upper portions through weathering where overhangs
occur. If the bedding plane is horizontal but dips slightly seawards
(D), there are ideal conditions for vertical cliffs with overhangs; these
cliffs are highly prone to toppling, as is the situation in the
Carboniferous Limestone cliffs at Goven's Head in Pembrokeshire.
When there are alternating bands of hard and soft rock, differential
erosion and weathering take place, giving the cliff a stepped profile
(E), this is particularly noticeable in horizontally bedded rocks.
Perfectly vertical bedding planes (F) lead to the formation of high
vertical cliffs, but this situation rarely occurs in reality. Where the dip
of the bedding plane of the rocks is towards the sea and greater than
20°, there is a gently sloping cliff, but blocks that are loosened by
weathering are likely to slide down slope, giving the cliffs a slightly
stepped profile (G). Where bedding planes are dipping away from
the sea (H), cliffs with a slope from 70° to vertical are likely to form;
differential erosion and weathering tend to give such cliffs stepped
profiles. Most of these bedding patterns are found in the cliffs at Kilve
in Somerset, which are dealt with as a case study later.
folding are important in determining the forms of cliff profiles. Toa lesser extent, the direction in which the cracks andjoints lie in othertypes of rocks, such as granite are also of significant in their cliff profiles.Horizon tal bedding (C), as in the chalk cliffs of the Seven Sistersin Sussex, enables the formation of high vertical cliffs that lose blocksfrom their upper portions through weathering where overhangsoccur. If the bedding plane is horizontal but dips slightly seawards(D), there are ideal conditions for vertical cliffs with overhangs; thesecliffs are highly prone to toppling, as is the situation in theCarboniferous Limestone cliffs at Goven's Head in Pembrokeshire.When there are alternating bands of hard and soft rock, differentialerosion and weathering take place, giving the cliff a stepped profile(E), this is particularly noticeable in horizontally bedded rocks.Perfectly vertical bedding planes (F) lead to the formation of highvertical cliffs, but this situation rarely occurs in reality. Where the dipof the bedding plane of the rocks is towards the sea and greater than20°, there is a gently sloping cliff, but blocks that are loosened byweathering are likely to slide down slope, giving the cliffs a slightlystepped profile (G). Where bedding planes are dipping away fromthe sea (H), cliffs with a slope from 70° to vertical are likely to form;differential erosion and weathering tend to give such cliffs steppedprofiles. Most of these bedding patterns are found in the cliffs at Kilvein Somerset, which are dealt with as a case study later.
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