File:The Quarterly journal of the Geological Society of London (13205894825).jpg

290
PROCEEDINGS OF THE GEOLOGICAL SOCIETY.
of fossils, published many years before* ; and though my present col-
lection, from the time and labour employed upon it, is probably the
most complete that has yet been made, there still are several unex-
plored chasms, from which new additions may be expected.
The drawing which accompanies this paper represents a vertical
surface parallel to the face of the cliffs and following their inflections.
It has no pretension to metrical exactness ; my principal object
having been to illustrate the distribution of the fossils. The horizontal
distances in the sketch are, from the construction, often erroneous ;
and for the thickness of the beds, I contented myself with such an
approximation as could be obtained without the use of the level f.
^ Chines^ and ^TJndercliffs.^ — The strata upon this part of the
coast rise uniformly, at an angle of about 2° to the horizon. The
only irregularities by which the cliffs are varied, are called in the Isle
of Wight, " Chines and Undercliffs," which are well described in
the excellent work of Sir Henry Englefield and Mr. Webster :.;;
the word " Chine" signifying those great fissures on the shore, which
are produced by the action of water in the beds of sand and clay,
here unsupported by solid strata ; so that when a spring or torrent
has once formed a channel, it soon cuts down to the shore, as in
Walpen and Whale Chines. In Black-Gang Chine, the process has
been interrupted by a firm group of ferruginous beds, which crosses
the streamlet, and has given origin to a cascade ; and the continuation
of these same bands has stopped the progress of other chasms (fig. 1)
between Black-Gang and Walpen Chines, in one of which the clay
has been entirely carried away, and a large surface of the ferruginous
beds exposed in a solid floor. In Ladder Chine the lower part of
the chasm is reduced to a narrow fissure, and finally closed before it
reaches the shore, by the firmness of a group including nodules in great
numbers, above which the sand is swept out in the form of a great
bowl. The subjoined figures illustrate these modifications of the
chine : —
Fig.l.
Fig. 2.
Remote Cliff near Walpen High.
Ladder Chine.

• A collection, including some very fine specimens from the south coast of the
  

Isle of Wight, has been some years exhibited at the Polytechnic Institution,
placed there very liberally by Captain Ibbetson, to whom I am indebted for the
freest access to its contents ; but no description has been pubhshed.
t The distances were measured with an ordinary rope of 300 feet, subdivided
and checked by frequent comparison with a fixed standard in a level field. For
the heights and thicknesses I used a light measuring-rod of 20 feet in four divi-
sions, which I found verv convenient in practice.