beaches surrounding the Longmynd and adjacent Lower Silurian rocks, where in situ they contain green and purple slaty fragments and pieces of felspathic trap, derived from the waste of that ancient Cambrian and Lower Silurian island. They may be identified by this circumstance, for in no other place with which we are acquainted does the Upper Caradoc assume this character; and Mr. Salter also gives the confirmatory opinion that the assemblage of fossils nearly resembles some of the groupings in the present rocks near Hope. It is, therefore, difficult to escape from the conclusion that the rocks generally must have travelled from that country across a space of from forty to fifty miles."
As I had no personal acquaintance with the Llandovery rocks on the flanks of the Longmynd, near Church Stretton. I failed to recognize the fragments of slate and other rocks which were found by my friend and colleague in the pieces near Northfield until I saw his collection in Jermyn Street, and many of the pieces certainly appeared to me, as before stated, very like the sandstones near Barr, and the pieces which were formerly to be seen lying on the old pit banks north of the Colmers near the Lickey.
Professor Ramsay then describes other localities where this Permian breccia appears, between the Forest of Wyre and the south end of the Malvern Hills. One of these localities, called Church Hill, nearly half way between Stourport and the Titterstone Clee Hill, is very remarkable, since it forms an outher of the breccia resting upon and entirely surrounded by Coal-measures. Professor Ramsay shows that these breccias extend altogether over an area of not less than 500 square miles,[1] and points to the fact that the great majority of the angular fragments seem to be all derived from the neighbourhood of the Longmynd near Church Stretton.
He arrives at the conclusion, from this great extension of the breccia, from the size (up to three-quarters of a ton) and angularity of the embedded fragments, and from the polished and grooved and striated surfaces of some of them, that they were transported and deposited by the same agency as the boulders in the boulder clay of the Pleistocene or Glacial Period, namely, by the action of glaciers, and icebergs or shore ice and ice floes.
As the action of glaciers is a subject to which my colleague has paid so much more attention than I have, his opinion is entitled to much more weight on the point than any I could give, and I therefore would draw the reader's attention to Professor Ramsay's explanation of the origin of this breccia, in opposition to the conclusion that I myself arrived at, that the fragments might be derived from adjacent rocks now concealed under the Permian and New red sandstone of the neighbourhood.
- ↑ See also his lecture to the Royal Institution. April 24, 1857.
