418 



NORTHERN PROLONGATION OF THE SYENITIC AXIS. 



face of the End Hill, usually in a compact or granular state, and in small yellowish green veins 

 ramifying through the granitoid and syenitic rocks. Again, there are transitions into compact 

 felspar, generally much fissured, the surfaces of the cracks being covered with yellow oxide of iron, 

 and occasionally with small crystals of spathose iron and calcareous spar. These felspar rocks are 

 largely cut into on the sides of the high road from Malvern to Ledbury, which crosses the hills 

 between the Worcestershire and Herefordshire Beacons. At Swinyard Hill the rock is granitic, 

 containing very minute scales of mica, but it graduates into syenite and greenstone. 



Besides these decidedly un stratified rocks, there are parts of the flanks of the hills in which the 

 same minerals are arranged more or less in layers, and to which Mr. Horner affixed the term of 

 gneiss. Some varieties of the latter may, I think, be considered simply as altered rocks of the 

 Silurian System. Among these, a species of contorted chlorite slate is very frequent. The chlorite, 

 which is scaly and foliated, takes the place of mica, and alternates with quartz, the two minerals 

 being generally in parallel laminae, but sometimes the quartz is disseminated and mixed with the 

 chlorite. On the whole, the rock has much the aspect of a chlorite schist in Anglesea, described 

 by Professor Henslow. (Cambridge Phil. Trans., vol. i.) There are also, on the western flanks of 

 Midsummer Hill, stratified rocks of ambiguous character, composed of quartzose hard conglome- 

 rates, with lumps of compact felspar and much of that mineral disseminated ; from their compo- 

 sition it is difficult to suppose they have not been connected with the volcanic origin of these hills. 

 These, as well as the grass-green, felspathic, sandstone of Holly Hill, described p. 416, may be 

 referred to that intermediate class of rocks, and to which the name of volcanic grits has been 

 applied. Under this supposition, we must imagine that in the manner previously explained, sub- 

 marine volcanic ebullitions were in activity upon this line of fissure during the earliest accumulations 

 of the strata of the Silurian System, and that long after these deposits had been formed, the present 

 syenitic chain of the Malvern burst up, dislocating and altering the adjacent strata. At the White- 

 leaved Oak, between Ragged Stone and Key's End Hills, the trap rocks (c) are contracted into a 

 small dyke (c*). To the north of this hamlet, the flaglike sandstones fold (a) concentrically around 

 this dyke, dipping off sharply to the west. 



The arch is broken near the summit, but as the chloritic and micaceous schists appear on the 

 contiguous slope of the hill, dipping to the east, there can be little doubt that the peculiar mineral 

 characters of this rock were due to volcanic agency. Indeed, at the extremity of the ridge on Key's 

 End Hill, the chloritic slaty beds are twisted and contorted amid great dykes of compact felspar 

 rocks, and impure syenite. Another proof of the alteration is near the summit of the Worcester- 

 shire beacon, where a mass of quartz rock occurs, which doubtless was produced in a manner 

 similar to that on the flanks of the Caradoc, the Wrekin, &c, (see pp. 227, 233.) 



Let us next direct our attention to the north end of the range, where Mr. Horner's description 

 terminates. Beyond the End Hill are two bosses of trap, the most southern of which is cut through 



88, 



