98 Mr Ainsworth on the Physical Geography 



at tlie same time, great facilities to the geognost ; for, as in this case, they will 

 generally be found to vary a little in their structure, — circumstances which, 

 of themselves, account for their solitary bleakness, when compared with the 

 other side, and oftentimes the adjacent portion of the hill. The first transi- 

 tion is, when the quartz becoming less extensive, and the mica more abun- 

 dant, at the same time assumes gradually a more lamellar aspect, and becomes 

 a distinct gneiss. This transition may be observed on the hill forming the 

 third summit to the south of Hereford Beacon. Its next transitions are two- 

 fold, on the one hand losing almost all parallelism of lamellae, the mica less dis- 

 tinct, and becoming more or less amalgamated with the other constituents, 

 forming a blue chlorite-slate, at times very much resembling the same forma- 

 tion as it occurs on the north of Tarbet Bay, in the Mull of Cantyre, and 

 known to Faujas St Fond and other old geologists by the name of Lapis ol- 

 laris. It is this rock, Avhich some authors, mentioning the occurrence of green- 

 stone in these hills, have, I suppose, mistaken for it. 



On the other hand, the mica becomes still more prevalent in the rock, the 

 slaty structure more decidedly marked, and in all its characters it approxi- 

 mates to mica-slate. This may be most distinctly seen in the London road 

 that crosses the southern extremity of the hills. De Saussure has very ex- 

 pressively called gneiss Granite veine. The term conveys the ground of dis- 

 tinction between gneiss and mica-slate ; yet the distinctive characters of this 

 rock are not sufiiciently well marked out to warrant its receiving the latter 

 appellation. To the west, it again becomes very compact, and less crystal- 

 line, the mica becomes almost entirely lost, and the rock becomes a dark 

 quartzose mass. Finally, this last hill is divided by the deep valley through 

 which courses the London road from a mountain-mass of gneiss and chlorite- 

 slate, whose compact structure, and power of resisting decomposition, have 

 given to the last-mentioned hills more acute summits than any others in the 

 range. The transition of the gneiss into green chlorite-slate, I did not ac- 

 tually trace in situ ; but, by fracturing some of the larger pieces rolled down 

 the sides of the hills, or even examining the broken stones on the road, many 

 examples will be found, fully demonstrating that it is a mere transition of the 

 first-mentioned rock into a more compact and less distinctly lamellar mass. 

 Beyond this, cultivation has effaced the bold outline and rugged grandeur of 

 the primitive mountains, and the line between the old rocks and the super- 

 incumbent formations becomes totally lost. 



From these investigations, the following general facts may be deduced : 



1. That the Malvern Hills are composed of that class of rocks denominated 



primitive, including granite, gneiss, and chlorite-slate. 



2. That these rocks are indefinitely stratified, having generally a direction 



from east to west, and rising with little variation to the north. 



3. That they contain no organic remains, nor are ever found alternating with 



or superimposed on rocks of a more modern formation, and that they 

 are of a formation much more ancient than the surrounding rocks ; and 

 though theoretically, it is not impossible that they might have assumed 

 theii* present situation at a period more modern than the deposition of 

 the old red sandstone, or even of the red marl, that they nevertheless 



