Page:The Geologist, volume 5.djvu/89

Rh places are met with under Permian and Trias deposits much nearer the surface than was previously suspected, and where the upper rocks gave no evidence of their proximity. The above bore has proved beyond doubt that a band of coal-measures lies under the south of Chorlton-on-Medlock, and possibly extends to Heaton Norris, being probably brought up by the great Pendleton fault, which most likely passes through the south of Manchester and joins the fault seen near the railway station at Heaton Norris previously alluded to.

In the fourth section, at Ordsal, Messrs. Worrall found the Trias beds four hundred and sixty feet in thickness without going through them. At the bottom of the bore the water became so salt that they discontinued the work, it being no longer fit for dyeing and such-like purposes. This is the first instance, to the author's knowledge, where salt water has been met with in the Trias near Manchester.

The fifth and sixth sections were at Skillaw Clough and Bentley Brook, to the north of the Newburgh station on the Manchester and Southport railway. These were some time since discovered by Mr. E. Hull, of the Geological Survey, and described shortly by that gentleman in the sheet explaining the map of the district. Further particulars were given of the details of both sections, and an analysis of the limestone was produced, which showed it to differ in its chemical characters from the thin ribbon-bands found in the Permian marls near Manchester, Patricroft, Astley, and Leigh; it was very like the yellow magnesian limestone found at Stank, in Furness, North Lancashire. Probably it might prove to be a different bed, and more like the great central deposit of magnesian limestone of Yorkshire than the thin beds previously alluded to.

December 24th, 1861.—J. P. Joule, LL.D., President, in the chair. Mr. Binney stated that many years since he had communicated to the Society a description of some markings on the surface of the Kerridge flags. He afterwards published, in Vol. X (New Series) of the Memoirs, a Paper on similar markings, found in the Upholland flags, near Wigan, and attributed then to the burrowing of an animal similar to the common lug-worm of our coast, the Arenicola piscatorum. Similar holes have since been found in rocks of various ages, from the Cambrian upwards.

The position of the Kerridge flags is, probably, one of the best ascertained in whole coal-field. It is in the lower division above the millstone grit. In the lower coal-field there are two main beds of flagstones: the first, or lower, the Rochdale series, under the "rough rock;" and the upper, or Upholland or Kerridge series, above the same rock, the chief workable beds of the lower coal-field of Rochdale and other districts, often termed the "mountain mines," lying midway between these two flag-deposits. This series of coal is now, and has been for many years, wrought under the Kerridge, flags so as prove beyond doubt the position of the latter. Some discussions have lately taken place at Macclesfield as to whether the Kerridge beds were Permian or Carboniferous. No one who ever saw Permian beds, could ever for one moment suppose Kerridge flags to belong to those strata. It is possible that Permian beds may exist in the low district lying between Kerridge and Macclesfield, as they have been met with at Hug Bridge on the south, and Norbury Brook on the north, but up to this time they have not been proved to be there.

Considerable interest has been excited by the discovery of what were supposed to be the foot-marks of some animals on the surface of the flags. He had been induced to make two journeys to Kerridge for the purpose of examining them; but although plenty of worm-holes and ripple-marks are to be found on the surface of the Kerridge flags, as yet he had seen no tracks of animals upon them.