r-RECARBONIFEROUS ROCKS OF CIIARXWOOD FOREST. 765 



fork of it a small exposure of ordinary banded slates dipping S.E. 

 25°. 



7. The section cannot be carried further across the strike. We must 

 pass obliquely to the north-west and enter BensclifT (fig. 3, p. 768). 

 In the field outside and south of this wood are two or three outcrops, 

 all slates or ashy gritty beds of an ordinary type, showing the usual 

 southerly dip. Entering by the ride that runs along the crest of 

 the hiil, we find successively two exposures of greenish- or bluish- 

 banded gritty slates, showing clearly the dip to S. About 20 yards 

 further is another, slightly redder. Then, after some distance, comes 

 the exposure marked red on the Survey map, with the letter F, the 

 symbol of so-called "felspar porphyry." This is a great mass of 

 coarse agglomerate, with no clear indications of bedding, cut up by 

 great divisional planes rather irregular in direction. The material 

 of this rock is a greenish ash, with a very few granules of quartz, 

 some rather ill-defined crystals and fragments of felspar, a few 

 small particles of dark slate, and numerous included fragments of a 

 felsitic rock, often so ill-defined externally as to resemble large 

 patches or blotches. As the matrix weathers to much the same 

 colour, they might often at first sight be mistaken for mere spots ; 

 but they are certainly included fragments. Under the microscope 

 the pyroclastic origin of the rock becomes evident, as we shall show 

 hereafter. The rough lumpy weathering unmistakably shows it to be 

 an ash, but gives few indications of large imbedded fragments. The 

 colour of the matrix is not uniform, but mottled with shades of 

 green. Separated from these rocks by a few yards of turf is another 

 group of rocks, similar in external character. The divisional faces 

 have a slight look of a roll ; but in these massive Charnwood rocks 

 it constantly happens that the stratification is wholly obliterated 

 and the divisional surfaces have no connexion whatever with 

 it. The materials are exactly the same as those of the previous 

 masses. 



Yet a yard or two further, all forming part of the same knoll, is 

 a ridge of rock consisting of an ash which includes large fragments 

 of an extremely flinty, pale green, fine-grained slate, much like the 

 fragments in the Old-John breccia-bed, but more altered. The 

 matrix also is not the same, being much more homogeneous. 

 There are appearances of a dip southerly ; but these cannot be 

 relied on. 



Some way further we come upon ridges of very fine hornstone- 

 like slate. The dip is almost certainly S. ; but as no bands are visible 

 it cannot be demonstrated. 



Passing along the ridge we come to the second red spot, marked F 

 on the map. This also is a pi]e of massive unstratified ashy rocks, 

 so precisely resembling those previously described that hand speci- 

 mens cannot possibly be distinguished. So far as the dip can be 

 conjectured, it is S. Just beyond are fine slates, showing lines of 

 bedding which indubitably have that dip. It is natural to surmise 

 that this second coarse ash, so like the former, is in fact the same 

 repeated by a fault. But the breccia at the base of one cannot be 



