On the Igneous Rocks of the Tortworth Inlier. 159 



a fourfold subdivision, the groups representing a definite sequence 

 of red and grey strata : — 



4. The Keele Series. Bed and purple sandstones and marls with 

 occasional seams of coal, and bands of entomostracan limestone. 



3. The Newcastle- under - Lyme Series. Grey sandstones and 

 shales, with four thin seams of coal, and at the base an entomostracan 

 limestone. 



2. The Etruria Marl Series. Mottled red-and- purple marls and 

 clays, with thin green grits ; a thin coal occurs 150 yards above the 

 base. 



; 1. Black Band Series. Grey sandstones, marls, and clays; numerous 

 thin seams of coal and Blackband ironstone ; one of many thin bands 

 of limestone is constant, 36 to 40 feet above the base. 



Spirorbis- and entomostracan limestones attain a maximum in the 

 Upper Coal Measures, but are not unknown in the productive 

 measures below. Indeed the two sets of measures are closely allied 

 lithologically, palaeontologically, and stratigraphically in this region. 

 The chief movements are pre-Triassic and post-Carboniferous. 



No attempt has been made to recognize the Black Band Series in 

 the Denbighshire, South Staffordshire, and Nottinghamshire coal- 

 fields, as they are indistinguishable from the productive measures in 

 the abseuce of Blackband ironstones. In each of these areas there 

 are divisions in the Upper Coal Measures which correspond with 

 the three highest divisions in North Staffordshire, and in all cases, 

 -except near the margin of the basin, where overlap occurs, they are 

 underlain by ordinary Coal Measures with coal-seams. It is there- 

 fore concluded that these higher Coal Measures were deposited in one 

 basin which included all the four areas dealt with, and that what- 

 ever movements occurred were of a local, and not of a regional 

 character. Judging by published descriptions, the higher series of 

 Measures appear to be present in other Midland and North-wot tin 

 coalfields, and in most of them the Keele Series corresponds to the 

 Salopian Permian of Prof. Hull. 



April 8rd. — Horace W. Monckton, Esq., E.L.S., Vice-President, 

 in the Chair. 



The following communication was read : — 



' The Igneous liocks and Associated Sedimentary Beds of the 

 Tortworth Inlier.' By Prof. Conwy Lloyd Morgan, F.B.S., F.G.S., 

 and Sidney Hugh Beynolds, Esq., M.A., F.G.S. 



It has long been known that igneous rocks occur iu the district 

 under consideration, but opinions are divided as to their intrusive 

 or contemporaneous character. Evidence is here brought forward 

 to show that the igneous rocks form two bands, the lower inter 

 bedded with Upper Llandovery strata, aud the upper overlain by 

 Wenlock, and that both bands are probably contemporaneous lavas. 



The igneous rocks appear at two horizons, both in the Charfield 

 •Green district and also in the district which includes Avening 



