80 Notices of Memoirs — E. D. Wellbiirn — Millstone Fish. 



A notable difference in the thickness of the strata and nature of 

 the coal-seams characterizes these structurally distinct areas. In the 

 centre of the syncline, near Shelton, the vertical distance between 

 the highest ironstone, or summit of the productive measures, to the 

 Bullhurst coal, or lowest workable seam, is about 1,300 yards. On 

 the anticline at Apedale only 800 yards of strata separate the same 

 horizons. This makes a remarkable decrease in thickness of 

 500 yards of strata in a distance of under three miles. The 

 reduction in thickness westward of the productive measures is 

 continued, though in a less degree, in the upper barren series, but 

 owing to the absence of shaft sections the amount cannot be definitely 

 stated. It is known, however, that the red marls forming the lower 

 portion of the upper barren series are more than 1,000 feet thick 

 near Etruria station on the Shelton property, and about 850 feet 

 thick near Silverdale, on the south-eastern limb of the anticline. 

 With the decrease in thickness a change has taken place in the 

 lower coals of the productive series. The seams which are house or 

 steam coals on the east change into gas and coking coals on the west. 



This great variability seems to show that separate areas of deposit 

 were being marked out by local movements of elevation and 

 depression, and thus fulfilling in North Staffordshire the conditions 

 characteristic of the Carboniferous of the Midlands generally, as 

 pointed out by Professor Lapworth.^ 



In North Staffordshire it happens that the areas of maximum and 

 minimum deposit correspond with a syncline and anticline. If this 

 be true generally, and not merely a local coincidence, we may expect 

 the coals in the unexplored coalfield which lies at the surface to the 

 west of the anticline, and which represents the eastern margin of 

 the great synclinal of Coal-measures beneath the Cheshire plain, to 

 be of a different quality from those in the anticline, while the 

 thickness of the measures will be increased. 



VI. — On some Fossil Fish from the Millstone Grit Kocks.- 

 By Edgar D. Wellburn, F.G.S. 



THE Millstone Grits are naturally grouped into three divisions, 

 viz. : (1) Eough Eock ; (2) Middle Grits ; (3) Kinder Grits at 

 base. The Middle Grits, consisting of grits, sand, shales, are sub- 

 divided into A, B, C, and D beds, A being uppermost. The Pennine 

 Anticline is mostly composed of these rocks, and on the Lancashire 

 side at the head of Calder Valley, on the south side in a quarry 

 at the summit, there is a good exposure of the D shales; in these 

 the majority of fish remains were found ; a few occurred at the same 

 horizon at Wadsworth Moor, Sowerby, Kilne House Wood, and 

 Eccup, Yorkshire. The majority are in nodular masses, few in 

 shales, and are associated with a marine fauna. The fish-bearing 

 beds were formed under marine estuarine conditions. They are 

 of great geological and zoological interest, as largely increasing 



1 " A Sketch of tlie Geology of the Birmingham District " : Geol. Assoc, 1898, 

 p. 364. 

 - Eead before the British Association, Section C (Geology), Bradford, Sept., 1900. 



