3°7 EXCURSION TO SWANAGE, CORFE CASTLE, KIMERIDGE, ETC. EASTER, 1896. Directors: W. H. HUDLESTON, F.R.S., REV. OWEN L. MANSEL, and H. W. MONCKTON, F.L.S., F.G.S. (Report b)' THE DIRECTORS.) PART I.-By MR. MONCKTON. THE headquarters during the whole of this excursion were at the Grove Private Hotel, Swanage, where a large number of members assembled on the evening of Thursday, April end, Mr. E. P. Ridley, F.G.S., was the member of the Excursion Com­ mittee to whom the arrangement of the Excursion was entrusted. Friday, AprilJrd.-Mr. Monckton acted as Director. The party drove from Swanage, through Langton Matravers, and Worth Matravers, to Renscombe Farm, and walked by way of West Hill to Chapman's Pool. On the way the Director made a few remarks on the general geology of the district, and pointed out the more important features of the magnificent cliff sections in view. He remarked that during the Easter Excursion of 1895 he had had an opportunity of addressing the members at Sandown, in the Isle of Wight. On that occasion he drew special attention to the great anticline of the Isle of Wight, which, due to a post­ cretaceous disturbance, commences in Weymouth Bay, and runs out to sea east of the Isle of Wight. The party were at that time close to the top of the anticline, which is there formed of the Wealden Beds. To-day they found themselves about forty miles west of Sandown, still on the line of the same great disturbance. They were, however, standing upon strata of greater age than the Wealden, for that series cropped out north of the road along which they had come, and during the whole drive they had been on beds of Purbeck age. Now they were upon the Portlandian, and the Kimeridge clay was seen in the cliffs and on the shore of Chapman's Pool below them. (See Fig. 2, p. 311.) At Sandown they had seen the southern side of the anticline in the cliffs between that place and Shanklin, but here it had been destroyed by the advancing sea. The Director further remarked on the curious fact that here, as in the Isle of Wight, the streams showed a tendency to flow .away from the south coast, through the chalk to the north, and expressed his belief in the theory that they had formerly been tributaries running off the northern side of the anticline to a JULY, 1896.J EXCURSION TO SWANAGE, great river which, starting with the Frome, crossed what is now sea between Poole and the Solent, and flowed away to the east, following the line of the syncline which runs east and west north of the great anticline. Chapman's Pool has long been a noted locality for Kimeridge clay fossils. It is referred to in our "Proceedings" as long ago as 1376, in a paper by W. R. Brodie," and was visited by the Association on Whit Monday, 1882; but the visit appears to have been a very hurried one.t On the present occasion ample time was allowed for collecting, and the President, Mr. E. T. Newton, noted amongst the fossils found: Ammonites biplex. Lucina minuscula (1). Arca (small species). Cardium striatulum. Astarte (Lucina) lineata. Pollicipes. Unfortunately the Ammonites here are, for the most part, crushed, but portions of the outer whorl were in several cases found in an uncrushed condition. Leaving Chapman's Pool, the party walked along a beautiful piece of under cliff formed by the slipping of the Portland Beds over the Kimeridge clay, and ascending the cliff by the coast­ guards' path, lunched in a grassy hollow near St. Alban's Head. After lunch the members walked on to the Head, and noticed, in passing, the interesting old chapel close to the coast-guard station. They then examined an old quarry on the brow of the cliff, and some time was spent in collecting Portland fossils, the following forms being noted-Cardium dissimile, Pecten iameilosus, Pecten sp., Tngonia muricata, and T. tenuitexta, and a large oyster. On the new edition of the one-inch Geological Survey map a much greater extension of the Lower Purbeck is shown at St. Alban's Head than on the old edition. According to the new reading, the basement bed of the Purbecks runs along the brow of the cliff towards the east from the coast-guard station. Leaving St. Alban's Head the party proceeded along the top of the cliff towards Swanage, and it is worthy of note that from the Head on­ wards the members were, it is believed, on ground never before visited by the Association. The linchets, or ancient cultivation terraces, described and illustrated by Mr. H. B. Woodward (Geology of England and Wales, and edition, pp. 6°7, 6°9, Fig. 100), attracted much attention, and gave rise to some discussion. On the surface of a field near the cliff one of the party picked up a fragment of silicified wood, probably coniferous. There was a short halt at Winspit Quarry, and the members then continued their way along the cliff to a quarry at Seacomb, where some time was spent, and several fossils were found, .. Proc, Geol. Assoc., vol, iv, p, 517. t Record 0/ Excursions, P' 3'9. CORFE CASTLE, KIMERIDGE, ETC. including: Cyprina implicata, Pecten lame/losus, and Pieuromya tellilla. The representative of the Tilly Whim oyster-bed was clearly seen. It contained numbers of shells of Perna. The base of the Lower Pur­ beck runs along the edge of the cliff; and there are numerous old workings in the Middle Purbeck on the hill-side to the south. The party proceeded as far as Durlston Head, where tea was found at the so-called Durlston Castle. After tea the members returned to Swanage. Saturday, April 4th.-Mr. H. W. Monckton again acted as direc­ tor, and conducted the party to Durlston Bay. Most of the morn- ~ ing was spent in an examination of '" the splendid sections in the Upper, ~ Middle, and Lower Purbecks shown in the cliffs. Unfor­ tunately the state of the tide was ! unsatisfactory, and prevented full :' justice being done to the highly fossiliferous strata. The Presi- dent's note of finds is as follows: Durlston Bay. Purbecks. Turtle (plates and bones). GOlliOP/lOlis (scales and teeth). Lepidotus (teeth). Mesodoll (teeth). Hybodus, 2 species (teeth). Corbula alata. Cyrena media. Ostrea distorta (Cinder bed). Paludina carinifera. Entomostraca (from cherty layers below Cinder). Mr. Hudleston's account of the visit to this locality on May 30th, 1882, is so good that it seems un­ necessary to add anything further." • Record of Excursions, p. 33' 31 0 EXCURSION TO SWANAGE, From Durlston Bay the members walked to the" caves" of Tilly Whim, which do not seem to have been visited in 1882. The "caves" are really old free-stone quarries, and Mr. William Brindley, F.G.S., gave an interesting account of the various build­ ing stones of the Isle of Purbeck., and the methods of working them. The photographs reproduced on Plate Xl give a very good idea of the Tilly Whim caves, and in the lower One (B) Durlston Head is seen in the distance. The section at Tilly Whim is as follows ~ I. Oyster or Perna Bed, about twelve feet thick at the west end, a great mass of oysters and numerous specimens of Perna Bouchardi occurs. A large fallen mass from this bed is seen in the foreground of Plate XI, B. 2. Limestone, about ten feet thick, extremely hard. It appears to represent the stone which is worked at St. Albans Head, close to the coast-guard station, but has not been worked at Tilly Whim.' 3. Shelly bed, about three feet thick, which forms the roof of most of the old ehambers "and levels. A large Ammonite, probably A. giganteus, was seen in situ about nine inches above the bottom of this bed. It was pointed out to the Director by Mrs. Hudleston. 4. The freestone which has been worked here. It is eight feet or more thick. 5. The chert series, which is very well seen at Tilly Whim, and is over twenty-five feet thick. Sponge spicules were noticed in the chert by the President. 6. Limestone-a specimen of Ammonites giganteus was seen in situ below high-water mark. After a halt for lunch at Durlston "Castle," the members visited a small quarry in the hillside above Tilly Whim. It is about 250 feet above the sea, and in it the Middle Purbeck Cinder Bed (No. 6 of Fig. I) is very well shown. The Middle Purbeck building-stone below the "Cinder Bed" has been worked by a level, and among the debris at the mouth the President found specimens of flinty chert, with Chara stems and Ostracoda in some abundance. The members then walked across the fields to the north, and visited a quarry in the Middle Purbeck which was being worked by the method so well shown in the sketch in H. B. Woodward's Geologyif England and Wales (and edit., p. 350, Fig. 55). The workmen produced out of little huts, just like those in the sketch, some fragments of the stone, with bones and plates of turtle, masses of scales of Lepidotus, and teeth and spines of Hybodus. This completed the programme for the day, but as the weather was beautifully fine and there was plenty of time to spare. PROC. GEOL. Assoc., VOL. XIV. PLATE XI. 6 rA.-THE TILLY \'VHIM "CAVES," SWANAGE. (For explanation of numbers, I to 6, see p.