Yol. 68.] PAL^OXTOLOGY OF THE WAEWICKSHIRE COALFIELD. 



603 



Near Nuneaton there is a sandstone at the base of the Keele 

 Beds which, being of some importance as a water-bearing rock, 

 has received the local name of the 'Porty-Peet Sandstone' (see 

 vertical section, PL LXI). It varies from 20 to 40 feet in 

 thickness, and occurs at from 100 to 170 feet above the main 

 Sjnrorbis Limestone. 



In the Keele Eeds fossil plants have been obtained from the 

 new sinking at Keresley, and from the red marls immediately 

 above the S2nrorbis Limestone in the Foleshill Clay-pit. The most 

 important plant is the characteristic Upper Coal-Measure species 

 Pecojoferis polymorj^lia Brongniart, which, together with P. miliom 

 (Artis), is not uncommon in one thin bed. Erect pith-casts of 

 Calamites sp. also occur. 



(B) The Permian. 

 In the foregoing pages it has been shown that more than half 

 of the area of the so-called ' Permian ' must be relegated to the 

 Carboniferous ; the remaining portion of these rocks (the Corley 

 Conglomerates and the Kenilworth Sandstones) will now be 

 considered. 



Thfe Corley Conglomerates. — In the Geological Survey 

 Memoir no distinction is drawn between the Carboniferous breccias 

 described above and the Corley Conglomerates, the lowest of which 

 I regard as the base of the Permian. The chief difference between 

 the breccias in the Keele Beds and these Permian conglomerates 

 is that, while the former are composed exclusively of fragments of 

 rocks (marls and sandstones, presumably of Upper Carboniferous 

 age) similar to those with which the breccias are interbedded, the 

 latter contain an abundance of pebbles derived from rocks foreign 

 to the coalfield. And, further, the great bulk of these pebbles in 

 the Corley Conglomerates are composed of rocks of Lower Carboni- 

 ferous age. The presence of large numbers of rounded pebbles of 

 Carboniferous Limestone in these beds suggests that, before this 

 period, the continuous deposition of Coal-Measure sediments had 

 ceased, and that a period of uplift and denudation had exposed 

 certain areas of Carboniferous Limestone, thus providing the material 

 from wliich the pebbles were formed. 



The following section of one of the Corley Conglomerates, which 

 was proved in the AVhitmore-Park Boring, is intended to show the 

 thickness and mode of occurrence of the bed: — 



CouLEY Conglomerate. Thickness (feet). Depth (feet). 



Conglomerate 13 597 



Calcareous, current-bedded, red sandstone, 



red marl, and breccia 45 



Conglomerate 18 660 



The upper bed of conglomerate is a hard massive rock, consisting 

 of small rounded pebbles set in a matrix of red sandy marl. The 

 lower bed of conglomerate is very similar, but is lighter in colour 

 and somewhat harder ; its constituent pebbles are rather larger, 



