The Geological Story of the Isle of WightHughes, J. Cecil (John Cecil)
Science
The Geological Story of the Isle of Wight
Hughes, J. Cecil (John Cecil)
Geology -- England -- Isle of Wight; Geology, Stratigraphic -- Tertiary; Paleontology -- England -- Isle of Wight
All the shells we have found are of sea creatures, and show us that
the Greensand was a marine formation. But the strata were formed in
shallow water not far from the shore. We have learnt that coarse
sediment like sand is not carried by the sea far from the coast. And a
good deal of the Greensand is coarser than sand. There are numerous
bands of small pebbles. The pebbles are of various kinds; some are
clear transparent quartz, bits of rock-crystal more or less rounded by
rolling on the shore of the Greensand period. These go by the name of
Isle of Wight diamonds, and are very pretty when polished. Another
mark of the nearness of the shore when these beds were laid down is
the current bedding, of which a good example may be seen in the cliff
at the north of Shanklin parade. It is sometimes called false bedding,
for the sloping bands do not mark strata laid down horizontally at the
bottom of the sea, but a current has laid down layers in a sloping
way,--it may be just over the edge of a sandbank. Again notice how
much wood is to be seen in the strata. Land was evidently not far off.
All along the shore you may find hard pieces of mineralised wood, the
rings of growth often showing clearly. Frequently marine worms have
bored into them before they were locked up in the strata; the holes
being generally filled afterwards with stone or pyrites.
The wood is mostly portions of trunks or branches of coniferous trees.
We also find stems of cycads. There has been found at Luccombe a very
remarkable fruit of a kind of cycad. We said that in the Wealden
period none of our flowering plants grew. But these specimens found at
Luccombe show that cycads at that time were developing into flowering
plants. Wonderful specimens of what may almost be called cycad flowers
have been found in strata of about this age in Wyoming in America; and
this Luccombe cycad,--called Benettites Gibsonianus,--shows what these
were like in fruit. Remains of various cycadeous plants have been
found in the corresponding strata at Atherfield; and possibly by
further research fresh knowledge may be gained of an intensely
interesting story,--the history of the development of flowering
plants.
On the whole the vegetation of the period was much the same as in the
Wealden. But these flowering cycads must have formed a marked addition
to the landscape,--if indeed they did not already exist in the Wealden
times. The cones of present day cycads are very splendidly
coloured,--orange and crimson,--and it can hardly be doubted that the
cycad flowers were of brilliant hues.
Public-domain text, read in full here on John Shaqi.
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