118 Baden Powell — Igneous Rocks of Charnwood Forest, 



These facts seem to show that through a considerable distance to 

 the N.W. the same subterranean force operated, perhaps in still 

 greater intensity, as is indicated by the violent disturbance and 

 almost vertical position of the limestone at Breedon, and the enor- 

 mous fault of 500 feet near Whitwick ; and would accord with the 

 fact of the absence of any indication of igneous eruption, or vent to 

 the hypogene matter, in these regions. 



Localities of igneous action S. W. side. — It is along the S. W. side of 

 the Forest hills that the marks of igneous action are by far the most 

 frequent and remarkable. There is, in fact, in this part one main 

 line running nearly parallel to the anticlinal axis, along which they 

 seem to follow a continuous series. 



On the south side of the road leading from Newtown to Mark- 

 field I noticed a small pit displaying a porphyritic rock, approaching 

 to Syenite. This I believe to be the most southernly point in this 

 series or range as yet detected. 



Continuing to the N.W. I have also noticed a small mass of a 

 similar porphyritic rock, at the end of the same range of hill which 

 at about half-a-mile further in the same line to the N.W. brings us 

 to the remarkable ridge bearing the inviting name of Hammerclifif, 

 marked in the Survey as porphyritic or altered slate along its sides 

 and ends, while the summit is an outburst of Syenite. There is a 

 specimen of Greenstone in the Museum of the Survey from Copt Oak 

 Farm, which lies just below the summit of this hill. 



Pursuing the line of this range still to the N.W., we have the 

 rocks of Birchwood plantation marked Greenstone in the Survey, 

 but in the Museum named porphyritic Cambrian, which agrees much 

 better with what I have noticed of its character. Further in the 

 same direction occurs the similar rock (by whichever name de- 

 signated), of Greenhill.^ These ridges at length terminate further 

 still in the same general line, in the extensive tract or elevated 

 plateau bounded by the porphyritic or altered Cambrian rocks of 

 High Towers and Tin Meadow, etc., on the south, and of High 

 Sharpley and High Cadman, etc., on the north, including among the 

 former those of Pedlar's Tor, which furnished the specimen of Crys- 

 taline Cambrian in the Museum of the Survey. In the midst of this 

 elevated plain, with its horizon everywhere bounded by these jagged 

 and fantastic forms of rock, amid partial attempts at enclosure and 

 cultivation, stands the monastery of S. Bernard. 



Character of altered rocks. — The extensive ranges of rock on the 

 monastery hills are graphically described by Mr. Jukes as presenting 

 all varieties and degrees of igneous action mixed in inextricable con- 

 fusion. The specimens, however, which I have collected from various 

 parts of this region all agree in exhibiting the same more or less grey 

 porphyritic appearance and manifestly faded character. 



Deposition of the New Red. — That the New Eed marl throughout 

 this district has been deposited unconformaUy upon the slate, and 

 therefore since its dislocation, is palpable from the mere fact of the 

 universally high inclination of the strata of the slate and the com- 

 paratively level position of the New Red. 



1 A different hill from that before mentioned, bearing the same name. 



