PBECAEBOKITEBOUS EOCKS OP CHAENWOOD FOEEST. 349 



(7) Igneous Rocks. 



We have not revisited more than one or two of the localities 

 where these occur since the date of our last paper, and therefore have 

 nothing to add from personal knowledge ; but we have detected two 

 new outcrops on the north-eastern side of the Porest — one in a spinney 

 between Whittle and Buck Hills, the other just east of the high road 

 on the crest of Nanpanton. Both are of the northern type (see vol. 

 xxxiv. p. 216), rather compact and decomposed. We could not 

 succeed in hitting off their junctions with the sedimentary rocks; but 

 a more minute search, under favourable circumstances, may yet dis- 

 cover them. 



Mr. S. AUport, however, has been fortunate enough to find 

 junctions, exposed by further quarrying, between the hornblendic 

 granite and the so-called Brazil-wood gneiss, showing that the 

 former, as we predicted, is intrusive in the latter *. He justly ob- 

 jects to applying to this the name " gneiss," though we are not per- 

 suaded that the term which he proposes for it, " micaceous schist/' is 

 much better. He has also been able to prove that this rock is only 

 a member of the Forest series exceptionally altered by *' contact 

 metamorphism " f. Mr. W. J. Harrison had previously discovered 

 small garnets in the " gneiss " J. The same gentleman has kindly 

 forwarded to us specimens of a very coarse variety of the "syenite" 

 from a pit near Stony Stanton, on the road to Sapcote. This might 

 almost be called a hornblendic granite rich in felspar, some of the 

 crystals of the latter mineral being nearly an inch long. 



Co7iclusion. 



As the result of the above investigations, we venture to extend, 

 with some modifications, the correlations proposed in our first paper 

 (vol. xxxiii. p. 784), as follows : — The Charnwood-Forest rocks 

 seem to fall naturally into three great groups, which, however, are 

 not separated by any very sharp lines of demarcation. The lowest is 

 the Blackbrook series. The middle group has for its base the coarse 

 ash-beds of the Monastery, the Hanging Stones, Timberwood Hill, 

 Chitterman Hill, Bensclift', and (east of the anticlinal) the spinney 

 above Whittle Hill. In the north-west region this gTOup contains 

 the immense agglomeratic masses of the High-Towers area ; in the 

 north-east the finer volcanic grits of the Buck-Hill district, and 

 probably Longcliff; but here and in the rest banded slates pre- 

 dominate. Bather high up in the group the beds of slate-agglo- 

 merate form an horizon which, as above described, can be traced 

 nearly round the Eorest district, and might, if thought desirable, be 



* Geol. Mag. dec. ii. vol. vi. p. 181. 



t The ashy rocks in the Stable Quarry, Bradgate, and at Stewards-Hay 

 Spring (vol. xxxiii. p. 201) are also examples of contact metamorphism. In the 

 first part of our paper the term " schist " was two or three times used where we 

 ought to have said *' schistose rock." In the sense in which we think it right to 

 use the former, viz. denoting rocks which are either distinctly " foliated " or have 

 undergone a similar amount of change, there is (apart from the Brazil-wood 

 rock) no schist in the Forest. 



\ Midland Naturalist, vol. ii. p. 77. 



