Vol. 58.| TO THE PHYSICAL GEOGRAPHY OF THEIR AGE. 189 
about 28 per cent. Igneous rocks and volcanic ash, in one case 
amounting to 15 per cent., are also present, with slates, argillites, 
and felspathic grits or quartzites, the last two together varying 
from 34:5 to 84 per cent. Certain specimens closely resemble 
some rocks in the lower part of the Hartshill Quartzite (basal 
Cambrian), the nearest exposures of which are now 12 miles away. 
In Mr. Gresley’s coliection I detected syenite, altered dacite, some 
slaty rocks—all of Charnwood type, with other slates and grits, a 
remarkable conglomerate with pebbles of a dark rhyolitic rock, 
representatives of the Coal-Measures including the ‘ burnishers ’ 
(ironstone-nodules), and probably Millstone Grit. At Coton Park 
Colliery two boulders (felspathic grits) were found; one weighing 
about a ton measured 3 ft. llin. x 3 ft.9in. x 2ft. 3in., and the other 
3 ft. 3in. x2 ft. 9 in.x 2 feet. Both these were distinctly striated, 
as were ten other smaller fragments, in regard to which I wrote ’:— 
‘While it is difficult to deny that certain of these markings may be striz, 
which have been produced in some way or other by the action of ice, | am 
more than doubtful of others, and am not convinced that this explanation is 
necessary for any..... At the same time, the very angular character cf many 
of the fragments, their size, and the great diversity which they exhibit, might 
fairly be brought forward in support of the hypothesis that ice had been one of 
the agents of transport.’ 
At this stage it will probably save time to make a few remarks 
on the source and transport of these Midland breccias. Those of 
Leicestershire, according to Dr. Brown and Mr. Gresley, apparently 
have been derived from the south and south-east. I infer from 
their variety that the materials have been gathered from a fairly 
large area, and from their form that they have not been much 
worn either by rivers or waves. The breccias of the western region 
(Clent, Enville, etc.) lead to the same conclusion. These occur as 
wedge-like fringes, very thick on one side, but dying out in a few 
miles. The land-mass which has furnished the breccias of the Clent 
Hills, if close at hand, must be represented in part by the rocks ex- 
posed in the lower Lickey Hills, and it must extend underground for 
a considerable distance to the north-west. That which has supplied 
the Enville breccias must be concealed somewhere to the east of 
that place. The rapid thinning-out of the Lower Trias in Central 
England towards the south-east, and the exposures of early Palseozoic 
or late Archean rocks at Charnwood, Hartshill, Dosthill, and the 
Lickey, indicate that an upland region once extended across, at any 
rate, this part of England in a general north-easterly and south- 
westerly direction. Much, however, of this is even now covered up by 
Coal-Measures, which in the South Staffordshire and Warwickshire 
district are often overlain by Permian. Indeed, even at the Lickey, 
the strip of Silurian and older rocks is flanked on both sides at its 
northern end by Coal-Measures.? From Dudley to Sedgeley, and over 
a rather large area about Walsall, Silurian rocks, mostly of Wenlock 
* * Midland Naturalist’ vol. xv (1892) p. 57. 
? A very interesting section, showing Coal-Measures with a seam of coal, 
resting on Cambrian quartzite, was exposed in digging the foundations for the 
“ounty Lunatic Asylum at Rubery. 
