60 REPORT — 1865. 



felspar, with a variable proportion of quartz ; and is remarkable, inasmuch as it in- 

 cludes masses varying in size from a walnut upwards, of a finer-grained and other- 

 wise dissimilar rock. In the great quarries near the village of Mount Sorel it is 

 impossible to distinguish satisfactorily the bedding from the jointage, but south of 

 Quorndon an east and west strike is observable. As in the Malverns, the rock is tra- 

 versed by trap-dykes, one of which may be seen near the Windmill, and another in 

 a quarry on the road which skirts Baddon Wood. At Kinchley Hill the rock con- 

 tains hornblende as well as mica, and proceeding southward, at Bazil Wood, some 

 large-grained diorite is seen associated with granite, both coarse and fine-grained, 

 which latter is succeeded by purplish-brown, highly micaceous, crumpled schist and 

 gneissic rocks, having an east and west strike. 



Other protrusions of these crystalline rocks occur in the neighbourhood of New- 

 town Linford, Grooby, Markfield, Hammercliff Hill, &c. In these knolls the rock 

 contains hornblende in place of mica. The felspar is partly of a pale greenish colour, 

 and uncleavable, and partly triclinic, having the same pinkish, subtranslucent ap- 

 pearance as that of the granite of Mount Sorel. Quartz is either absent altogether, or 

 occurs in small proportion only, and occasionally, as near Grooby, the rock contains 

 epidote. Although similar in mineral composition, these rocks vary slightly in their 

 general appearance, according to texture and to the relative proportions of their 

 hornblende and green felspar, forming parallel belts or beds of rock of somewhat 

 dissimilar aspect, Avhich on the north and west of Grooby may be seen to trend 

 from W.N.W. and E.S.E. to N.N.W. and S.S.E. ; but further westward, as at 

 Markfield and Cliff Hill, the rock is more uniform in structure, and the direction of 

 the strike cannot be determined satisfactorily. At Hammercliff Hill part of the rock 

 is dark-coloured, from the abundance of hornblende it contains. 



The Lower Cambrian rocks, through which these knolls protrude, have been up- 

 raised along an anticlinal axis, which extends N.N.W. and S.S.E. from Whitehorse 

 Wood to Holgate Lodge. From this line the rocks dip away to the N.E. and S. W., 

 at angles varying from 30 to GO degrees; but from this general direction of the 

 dip there are many local deviations. In appearance they resemble precisely the 

 Lower Cambrian rocks of Wales, and consist of purplish, blue, and green slates, 

 with grits and conglomerates, and interstratified beds of volcanic porphyry and ash. 

 These latter are well seen in the high ground which extends from Hobs Hole to 

 Green Hill, at Bardou Hill, Birch Wood Hill, and along the ridge which stretches 

 N.N.W. from Bradgate Park. Encircling this small area of exposed Lower Cam- 

 brian rocks are the Keuper marls, which rest on them horizontally, except on the 

 north, where the underlying sandstone (Water-stones) intervene the marl and the 

 Cambrian rocks ; and, as observed by Mr. Howell, " it is worthy of notice that the 

 marl contains fragments and bouldersof the older rocks where in contact with them"*. 



In the Malvern district the oldest overlying rocks are referable to the age of the 

 Middle Lingula flags, which rest unconformably on the gneissic rocks of the hills ; 

 and in the shallow-water conditions under which their lowest beds were accumu- 

 lated, and in the successive overlap of the succeeding ones, we learn that the meta- 

 morphic rocks formed land in the Lower Cambrian sea, and that an interval of un- 

 represented time preceded the deposition of the Malvern Lingula flagsf. 



Now, with respect to the age of these quasi-syenitic and granitic rocks of Cham- 

 wood Forest and its vicinity, their massive and highly crystalline condition might 

 countenance the view that they had had an igneous origin, although they show, 

 here and there, undoubted traces of stratification, without any change in mineral 

 character ; but assuming for the moment that they have had this origin, there is a 

 total absence of any evidence of heat-action upon the contiguous Lower Cambrian 

 rocks, and we may therefore conclude that the latter had no existence at the time 

 of their eruption. On the other han-1, regarding them as metamorphic, their mode 

 of occurrence with respect to the Cambrian rocks, and the circumstance that some 

 of the grits contained in the latter, as, for instance, that near the windmill north of 

 Markfield, are made up of rounded grains of felspar, hornblende, and quartz, tends 

 equally to show that they existed before the era of the Lower Cambrian rocks. 



* Memoirs of Geological Survey. Explanation to Horizontal Section, Sheet 48. 

 t See further, the paper already quoted in Quart. Journ. Geol. Soc. vol. xxi. part 1. 



