598 MK. E. D. VEENON ON THE GEOLOGr AND [DeC. I912, 



syncline pitching towards the south and having its longer axis in a 

 north-and-south direction. 



The strata dip steeply away from the eastern, northern, and a 

 portion of the western boundary ; but, towards the centre of the 

 basin, they become almost horizontal. South of Polesworth, and 

 east of the coal-outcrops, a subsidiary anticline causes the measures 

 to roll over and dip eastwards into the boundary-fault. There is 

 evidence of a similar faulted anticline beneath the Trias, at Brandon 

 in the south. 



The greater part of the syncline is concealed from view by the 

 spread of Upper Coal Measures, Permian, and Trias, which come on 

 successively towards the south. 



The Earren or Upper Coal Measures. — The rocks of this 

 group may be conveniently divided into three sub-groups, each of 

 which possesses certain definite lithological features. Though 

 somewhat variable in character and thickness, each sub-group can 

 readily be traced throughout the greater part of the district. 



Fossil plants are much more difficult to obtain from this group 

 than from the Productive Measures — partly because the flora on 

 this horizon, though sometimes rich in individuals, is poor in 

 species ; but largely because of the paucity of exposures in the 

 Ked Rock area. 



The Nuneaton Clays. — This sub-group consists of a series of 

 red and purple mottled marls and shales, often apparently un- 

 stratified. A thin Spirorbis Limestone ; several beds of a peculiar 

 green gritty sandstone or ' Espley Rock ' ; and, locally, a bed of 

 hard green breccia made up of angular pebbles of red and green 

 marl, of vein-quartz, and of ironstone, ranging up to 4 inches in 

 length, are also characteristic of this sub-group. The breccia is 

 best seen in the south ; but the Espley Rocks become coarser, and 

 their constituent fragments of green shale are more angular, in 

 the north of the district at Whateley Clay-pit. 



Both in the breccias and in the Espley Rocks are pebble-like 

 pieces of ironstone, made up of a nucleus and concentric coats 

 strongly suggestive of a decayed basic igneous rock. 



The whole of the beds are extremely variable in thickness from 

 place to place, but the sub-group averages about 100 feet. For this 

 reason, and also because of the high dip of the beds, the [N'uneaton 

 Clays have a very narrow outcrop, which strikes roughly parallel to 

 that of the coal-seams. To the north of Wilnecote the jS'uneaton 

 Clays are either very thin, or locally absent. Good exposures are 

 to be seen on the west of the district at Cliff and Whateley, near 

 Kingsbury, and again on the east at Stockingford and Nuneaton, 

 where several extensive marl-pits have been opened out in these 

 measures. 



In order to illustrate the nature of the rocks, measured sections 

 of two of these marl-pits are given below : — 



