341 LYME REGIS. As it is not our intention to describe the geological structure of the entire English coast, but only to point out some of the most remarkable features of those parts which are visited as places of occasional retirement, or periodical fashionable resort, we must pass by the coast of Hampshire, the Isle of Wight being sufficiently described in a former page. The coasts of Dorset and Devon are peculiarly interesting to the geologist, presenting at almost every part bold and characteristic sections of the various secondary rocks of which they consist. The first place of importance is Weymouth, which, as well as the island of Portland, has long attracted the attention of the practical geologist. An elaborate memoir of the geology of Weymouth and its vicinity was read before the Geological Society in the year 1830 by Dr. Buckland and Mr. De la Beche. The district is spoken of, by these justly celebrated observers, as one of great importance, from its position near the south-western termination of several principal formations of the island, from the existence of a coast section, which forms an interesting ob ject of comparison with the north-eastern terminations of the same strata on the coast of Yorkshire, and from the remarkable exhibition of the effect of those disturbing agents which have acted upon the strata since the period of their consolidation. As it does not enter within the range of our inquiries to examine this district, we must refer the reader to the memoir already mentioned,* and Professor Sedgwick's remarks on the same subject in the Annals of Philosophy. + Mr. De la Beche was the first geologist who published an account of that portion of the coasts of Dorset and Devon, from about three miles west of Bridport Harbour to Sidmouth.‡ The cliffs, proceeding from Bridport Harbour to Sea Town, are not of great elevation. They at first consist entirely of beds belonging to the oolitic series, but the lias is soon seen at the base of Down Cliff rising from beneath them, and may be traced, almost without interruption, as forming the lower and larger portion of the cliff, for a considerable distance beyond Lyme * Geological Transactions, second series, vol. iv. "Geological Transactions," second series, vol. i. Regis. At the highest point of Down Cliff the green sand formation is seen resting upon the oolites, and the same rock lies immediately upon the blue lias at Golden Cap, Shorn Cliff, and Black Ven. Golden Cap is a remarkable cliff, consisting, as already stated, of blue lias and green sand, about five miles east of Lyme, and has an elevation of about 600 feet above the level of the sea. At Black Ven, which is situated between Charmouth and Lyme, regular, compact, and unbroken beds of chert appear in the green sand. The same substance occurs at Golden Cap Hill and Shorn Cliff, but as loose, angular, shattered fragments. To the west of Lyme lias is again observed at the base of the cliff, but the connection of that rock with the green sand which rests upon it, as in the portion of the coast already described, is concealed by a beautiful undercliff, composed of fallen masses of green sand and chalk. At the most westerly point of the Ware Cliff, chalk may be observed, resting upon the green sand, and it forms the caps of the hills of Pinhay, Whitelands, Charlton, Rusedon, and Dowlands. Beyond Axmouth it appears again at White Cliff and Beer Head, reposing on L green sand. Proceeding west, the chalk still continues to cap the hills, decreasing in thickness, and disappears at Dunscombe hill, a short distance to the east of Sidmouth. At Dowlands, near Axmouth, the red sandstone formation makes its appearance; and at Axmouth Point the green sand is seen immediately above it. At Seaton it forms some low cliffs, and from thence, with the exception of White Cliff and Beer Head, it constitutes the lower part of all the cliffs to High Peak, on the west of Sidmouth; proceeding westward, it forms the entire cliffs as far as Babbacombe Bay, where it rests on limestone. The conglomerate at Teignmouth includes large rounded masses of porphyry, from a few inches to two or three feet in diameter; and, between Teignmouth and Babbacombe Bay, it contains small pebbles of the same limestone which it rests upon at the latter place. The green sand in the neighbourhood of Lyme Regis contains many characteristic and well preserved fossils; but the collector will be chiefly interested in those of the lias. The remains of the icthyosaurus are not rare, and many other fossils are found in abundance, but chiefly at Black Ven. The student will also be much interested in the examination of the faults in the neighbourhood of Lyme, to which we would especially direct his attention. TORQUAY. The geology of Tor and Babbacombe Bays was examined by Mr. De la Beche in the year 1827, and the result of his observations may be found in the Geological Transactions.* The coast sections in the vicinity of Torquay are peculiarly interesting to the geologist, though this vicinity will afford a less variety of fossils to the collector than many others which might be mentioned. The principal rocks are the Exeter red conglomerate, the carboniferous limestone, the old red sandstone, and some varieties of trap. The Exeter red conglomerate is well exhibited in Babbacombe and Tor Bays. It contains fragments, which are usually small, of carboniferous limestone and other rocks; but there is another variety, in which some of the fragments are of great size, being often a ton or more in weight. The cliff extending west from the Ness Point at Teignmouth "exposes a section "Geological Transactions," second series, vol. iii., p. 161. |