514 
Mr. Buckland on the 
and as there is no decisive section at the Lickey along its line -of 
junction with any of the surrounding strata, we are fortunate in 
being able to supply this deficiency from the accurate and valuable 
observations of Mr. Aikin, on a rock which he considers absolutely 
identical with it at no great distance in Shropshire, where in the 
well known hills of the Wrekin and Caer Caradoc, the position of 
the quartz rock is, according to his observations (Geol. Trans, vol. 
i. p. 208, and Plate annexed) distinctly marked, extending along a 
considerable line intermediate between the soft grauwacke slate that 
flanks these chains on their south-east base, and the trap rocks that 
form their summits ; their middle region or south-east slope being 
composed of quartz rock dipping under the grauwacke slate, and 
being identical with that of the Lickey in every circumstance of the 
most minute particulars of its character. Incumbent on the grau- 
wacke slate along great part of this extent, is a thick mass of tran- 
sition limestone, which terminates suddenly in the steep escarpment 
of Wenlock Edge overhanging the grauwacke slate, and facing to- 
wards the north-west ; * the same limestone occurs also in a similar 
position on the south-east side of the Wrekin, and though it may 
perhaps be doubtful whether the quartz rock ought to be ranked in 
the class of primitive or transition formations, it is certainly more 
ancient than the youngest beds of the grauwacke slate, and probably 
referable to a place among the older members of the grauwacke 
formation. 
* This soft variety of grauwake slate, which is often found in the neighbourhood of 
transition limestone, is commonly distinguished in Herefordshire by the name of water- 
stone, as it decomposes readily into a soft grey clay the surface of which is very tenacious 
of water. Near Abberley the appellation of mudstone is given to the same slate for simi- 
lar reasons, and in the Shropshire Coal-field it is known by the name of Dye-earth. In a 
subsequent paper on the coal-fields of Somerset and Gloucester, I shall give it the name of 
transition limestone shale, and enter more at large into its history and relations. 
