PKECAEBONIEEEOTTS KOCKS OE CHAKXWOOD EOEEST. 755 



square miles in trie N.W. corner, pass insensibly into " felspathic 

 porphyry," of which a few isolated patches are also marked in the south- 

 east hills. Some large masses of syenite, more or less connected, 

 occur in the southern part, and two others nearer the centre. Bar- 

 don Hill is coloured as a large mass of " greenstone," which rock is 

 also shown in the neighbouring Birchwood Plantation, and in several 

 small isolated patches on the N.E. of the Forest. From several 

 important points in the above mapping, as will be seen hereafter, 

 we are compelled to differ, as well as from the memoir published 

 by the Survey. 



It must be remembered that in the Forest, while it is usually 

 tolerably easy to recognize the general character of the rocks, the 

 task of coordination and correlation presents peculiar difficulties, 

 owing to the prevalent absence of cliffs, ravines, or continuous sec- 

 tions, the large amount of country covered by vegetation or cultivated 

 soil, the insulation of the exposures by these, the absence of indica- 

 tions of dip, with other peculiarities in some of the coarsest fragmental 

 deposits, and, lastly, to a certain perversity, as one might almost 

 call it, in the country, which seems always to cover up just the most 

 critical part of a section. Hence the authors wish it to be under- 

 stood that the order of stratigraphical sequence assigned to the 

 sedimentary rocks in this paper must be regarded as open to revision, 

 and as the best hypothesis which, under the circumstances, they 

 have been able to frame. 



The rocks of Charnwood Forest are usually described as forming 

 a great anticlinal, the axis of which runs from N.W. to S.E., along 

 a valley rather on the eastern side of the district. This, however, is 

 only true in a general sense. Still it will be convenient for descrip- 

 tion to retain the term, and to carry our sections from either side up 

 to this "anticlinal valley," where the dip of the beds changes. We 

 shall describe the principal exposures in order along a series of 

 sections, beginning from the north-eastern or Loughborough end of 

 the region, going southwards to AVoodhouse Eaves and Swithland, 

 and then round the other side of the anticlinal by Bradgate, Mark- 

 field, and Bardon, to the extreme northern end at "Whitwick and 

 Gracedieu. Certain localities, which cannot be conveniently grouped 

 under any of these sections will be separately described. 



Description of Sections. 



1. Leaving Loughborough by the Loughborough Lane, we first 

 see live rock in an old quarry on the left-hand side of the road, called 

 on the map Forest Gate. There was formerly another on the right- 

 hand side. Unfortunately, we were not then aware of the import- 

 ance of this rock, and took no specimens. It is now filled up. As 

 far as we remember, it was ordinary blue slate ; and the fragments in 

 walls in the neighbourhood confirm this. Professor Jukes describes 

 it as compact slate, with faint cleavage, greatly cut up by joints, and 

 with a few faint streaks of colour giving a N.E. dip of 85°. The rock 

 on the left-hand side is very singular. Its dip is well marked, very 



