1. A mass of limestone composed almost entirely of organic remains, and containing much iron, with madrepores between the strata |
90 | feet |
2. Ten thin beds of blue and close-grained limestone, with clay between them, in which madrepores are imbedded |
8 | |
3. Limestone composed entirely of particles bearing marks of organization |
18 | |
4. A very thin stratum of red clay, covering | ||
5. [1]A layer of coaly matter, one inch thick. |
- ↑ The following more detailed section of the beds lying above the coal marked No. 5, in the text, has been communicated to the Society by G. Cumberland, Esq.
1.—Sparry limestone, the edges of which being tinged with iron resemble lepidolite ft.
10In. 2.—Red, blue and white schistose clay 26 3.—A stratum very full of fissures, the laminæ composed of quartzose sand united by a quartzose cement 9 4.—A stratum of what is called “ Dun marle,” containing very angular fragments of limestone and ironstone: the marl is red, blue and white, and is speckled with ferruginous sand and pieces of schistose clay 6 5.—A very hard mixture of ironstone and quartzose sand with portions of an oolitic texture 9 6.—A ruddy and arenaceous limestone, ochreous, passing into ironstone of a tine grain 2 7.—A stratum of ironstone I inch thick; then a very hard and line grained arenaceous stratum 6 1 8.—A line grained arenaceous stratum 2 6 9.—A stratum containing fragments of shells 4 10.—A stratum containing fragments of shells and corals, in part argillaceous, and having the oolitic texture; of a brown colour 4 11.—Three inches of ochreous clay with blue schistose clay, with oblong geodes of red iron ore very compact and hard 3 12.—Limestone having throughout the oolitic texture 12 13.—Schistose clay or stone with nodules of coral 5 14.—Very arenaceous limestone with oolitic texture. 1 15.—Schistose wet clay coloured by iron with nodules 2 16.—Limestone, somewhat oolitic, tinged with iron, containing broken shells. 4 17.—Dove-coloured, oolitic limestone with broken shells. The strata cracked. 8 3 18.—Grey compact limestone, irregularly oolitic 6 19.—A stratum somewhat arenaceous, tinged with iron 2 6 ─── 20.—A schistose limestone 1 21.—Two layers of soft limestone tinged with iron, separated by a layer of schistose clay 2 inches thick 22.—Dark and fine grained limestone, divided in part by loose schistose clay 2 23.—Seven thin layers of schistose limes tone, separated by loose friable schistose clay with nodules, the whole containing many shells of the winged anomias and the anomia producta, with coralloids 3 24.—Light coloured and fine grained limestone without animal remains, in texture resembling No. 22 1 25.—Limestone with small broken encrinites 2 26.—Dark oolitic limestone with broken shells 2 27.—Limestone with broken shells throughout 1 28.—Schistose clay 3 29.—Fine siliceous rock without shells 1 6 30.—Rock with oolitic structure partially coloured by blue clay 2 3 31.—A reddish limestone with small arms of the encrinite, their cavities filled with ochreous matter 6 32.—Coal about 2 inches thick, resting upon ironstone and red schistose clay, three or four inches thick. 6 Of these strata only two will burn into good lime, the rest being too arenaceous for the purpose. The organic structure observed in No. 3, of Mr. Bright's section is the oolitic texture noticed by Mr. Cumberland. Mr. Cumberland observes that although this texture I is still visible in the arenaceous rocks of a mixed nature, it disappears in those which are purely siliceous. He also mentions that an oolitic limestone may be observed lower in the series of the east side of the combe that separates the pure limestone from the black rock or swine-stone. The fossils of the black rock are the winged anomiæ, and rarely the anomia products, the palates of fishes, the claws of crustaceæ, corallines of various kinds, the mycetita of Woodward, the medusa encrinite, and millions of the stalks of encrinites, both round and oval. There has likewise been found in it a complete specimen of the head of an encrinus, and other heads of the encrinus have been observed imbedded in the limestone, and but little distorted. They were first noticed by Mr. Miller surrounding calcareous concretions in the black rock, which are penetrated with petroleum.
Petroleum sometimes exudes from the rock in small quantity; it is very hot to the taste, and is used by the masons for an external application, assisted by friction, to remove rheumatic pains. The black rock is quarried for paving stones
