PRE-CARBONIFEROUS FLOOR OF THE MIDLANDS. 
73 
The Dos thill Shales are remarkable for the abundance of 
worm-tracks which they contain. In a small field-pit, quite 
close to the main road, at the southern extremity of the hill, 
there is a good exposure of these “ annelidean” shales, through 
which a neck or pipe of igneous rock is seen to rise, spreading 
out above into a horizontal sheet. Altogether the Cambrians 
of Dosthill occupy but a small area — less than a square mile. 
I have not detected the quartzite in situ here, but it is probably 
at no great depth, as large loose blocks lie upon the surface, 
brought up, it may be, along the line of fault. 
It would thus appear that the floor of the Warwickshire 
coal-field is composed of Cambrian rocks, the Silurian and 
Devonian strata being absent. This is confirmed by the 
Leicestershire borings to which we shall presentty allude. 
A note as to the discovery of the true age of the Pre- 
Carboniferous rocks of Warwickshire may not be out of 
place here. In February, 1882, I read a paper* before the 
Philosophical Society of Birmingham, in which it was insisted 
that the hard rocks that occur as pebbles in the Permian, 
Bunter, and Keuper strata of the Midlands were derived—not 
from Wales and Scotland as Professors Ramsay and Hull had 
asserted—but from old rocks which formerly stretched more 
or less continuously right across Central England, and of which 
patches still existed at the surface. This paper, and the 
discussion which followed it, led to the announcement a 
few weeks later by Mr. F. T. S. Houghton and Professor 
Lapworth of the distinction between the Llandovery sandstone 
and the Cambrian quartzite of the Lickey Hills. By this time 
I had myself examined the Lickey Hills and I was at once 
struck with the resemblance between the true quartzite, which 
forms the greater part of the ridge, and specimens of the 
Hartsliill quartzite which my students had brought to me 
when I was curator of the Leicester Museum. This Hartsliill 
rock had been mapped as “ altered Millstone Grit,” by the 
officers of the Geological Survey. 
I found that my doubts as to the correctness of the Survey 
classification were shared by Professor Lapworth, and in May, 
1882, we paid our first visit to Nuneaton. A glance at the 
quartzite there was almost sufficient to prove its identity with 
that of the Lickey, so exact was the petrological agreement. 
Within the next few days we found the Pre-Cambrians below 
the quartzite at Caldicote, and the fossiliferous Cambrian 
shales both at Stockingford and Dosthill. 
(To be continued.) 
* On the Quartzite Pebbles contained in the Drift, and in the Triassic 
strata of England, and on their derivation from an ancient Land Barrier 
in Central England. Proc. Phil. Soc., Vol. III., p. 157. 
