Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/214

 or from above downwards; in the former case, the force must have been applied to the elevated portion, in the latter, to that which is depressed. It does not appear how a great extent of strata can be first raised and afterwards supported in its new position otherwise than by a mass of fluid matter, capable of subsequent consolidation, bursting up from below with a great force; nor on the other hand is it easily conceivable how an extensive depression can take place except by some great cavity under the depressed part giving way. Now, in the present instance, if we examine the elevated extremity of Benthal Edge, we shall find that between the abrupt termination of this, and the low range of limestone called Wenlock Edge, (hereafter to be described) which lies about a mile to the west, the whole intervening space is occupied by shattered fragments of limestone strata and great irregular deposits of die-earth, but without the smallest appearance of basalt, amygdaloid, or those other unstratified rocks which by many geologists are considered as the great instruments by which the heaving up of strata is effected. The non-existence, at least the non-appearance, of these in the present case, countenances the opposite hypothesis of depression; and this appears still more probable from an examination of the coal strata superincumbent on the eastern end of the limestone in the parish of Brosely, which are full of fractures, thus indicating very considerable disturbance in that part.

The western range of Limestone runs precisely parallel to that already described as far as the Severn; its average height rarely exceeds three hundred feet above the level of this river. It forms an unbroken range with a nearly even top, on which account it is known by the name of Wenlock Edge. It is very full of tubulites and other coralline remains, but I have never seen in it any of the heavy-spar which characterizes the eastern range. In its line of direction and