NOTES AND QUERIES. 



127 



NOTES AND QUERIES. 



Glacial Action in Wales.—" At the mouth of a lateral valley openmg into 

 the vale of the Ithon, in Radnorshire, at the turnpike-gate above Llanbadam 

 Fynydd, there is a low hill somewhat in advance of the slopes of the underlying 

 schistose rocks. A road-cutting exposes a section of tliis hill about fifty feet from 

 its base, and the same from its summit. It is seen to be composed of materials 

 far different to those of the soft coarse rocks around, being, in fact, a collection of 

 boidders and angular fragments, with smaller pebbles and mud. The excavation 

 made by the stream at the V-ase of the hill shows the same confused collection of 

 large stones, little-rolled, with coarse detrital material. The boulders are prin- 

 cipally giitty portions of the Silurians found in the hills at the sources of the 

 stream. The residual products of a glacier appear to be here apparent. — S. R. P." 



Mammalian Remains. — " Dear Sir, -The remains of Mammalia in the 

 Dover Museum are very few, and are mostly those of jMammoth. The collection 

 consists of, large tusk of jMammoth, another large tusk, apparently of a different 

 species, trawled up in the North Sea, off Holfoi'dness ; remains of jVlammoth, and 

 large stags' horns, from Faversham ; Elephants' grinders, dredged up on the 

 Calais oyster-ground, off tlie French coast ; part of upper portion of a bear's 

 skull, from the Cherry Gardens, Folkestone ; cores of horns of Bos, from Faver- 

 sham ; remams of Mannuoth and of Bos, from Heme Bay. — Yours, &c., Charles 

 Gordon." 



Landslip at the Isle of Portland. — " In the Isle of Portland, early on 

 Sunday morning, December 26th, an unusual kind of noise was heard by some of 

 the inhabitants at the village of Chesil, compared, by the narrator, to the con- 

 tinual falling of a stone wall. On the return of daylight it was found to have 

 proceeded from the sliding away of a large extent of under-clifF, covering an area 

 of from twenty to twenty-five acres, which had caused the sinking of an enormous 

 mass of l)roken stone, the cUhris of the adjoining; quames, and the accunnilation 

 of very many years. The scene of the occurrence is on the west side of the island, 

 overlooking the great west bay, about 200 or 300 yards from the village of Chesil. 

 A slight sinking had been observed by one of the quaiTymen on the previous 

 afternoon, but it was not until an hour after midnight the general mass gave way. 

 The main cliff, or escarpment, is, at this point, about 200 feet above the level of 

 the sea ; the north end is 495 feet, but with a considerable southerly dip. The 

 upper strata of the Isle of Portland are the Purbeck, or fresh-water limestone, 

 alternating with layers of clay or dirt, as it is here called ; one ©f which seams 

 contains the fossil trees and Cijcadece. Below this is the true Portland-series, 

 consisting of beds of stone interspersed with bands of chert and flint, and termi- 

 nating with the Portland-sand. Below all these the Kimmeridge-clay — the 

 formation which yields the well-known Ijituminous schist — forms the general 

 substratum of the island. It forms the anchorage ground of the Portland road- 

 stead, and is the stratum on which the Chesil-beach has accumulated. The 

 immediate cause of the landslip undoubtedly has been the action of the springs 

 from behind and above passin*^- through the numerous fissures in the beds of solid 

 limestone, and carrying away in their course the soft and yielding clay ; and thus 

 undermined, the superincumbent mass has sunk downwards and outwards. In 

 ascending from the beach, the visitor will be first attracted by the low under-clifi 

 of Kimmeridge-clay, which, from lateral pressure, has been pushed forwards 

 beyond the beach into the water, and forced upwards with the shingle over it, so 

 as to present an escarpment, or outer face, towards the sea. The condition of the 

 displaced under-cUfl" is, more or less, the accompaniment of all landslips on the 

 coast, and was remarkably exhibited in the great landslip near Lyme Regis, De- 

 cember 25th, 1839. On that occasion, the argillaceous stratum of under-cliff was 

 tilted up to a height of thirty feet, leaving a corresponding depression behind, 

 which soon became filled with the fresh water issuing from the main land. At 

 Portland, a small pond only has been formed. A little way up the cliflfj a singular 



