78 



sjfenite, a further search was instituted, and a small boss of this rock 

 was laid bare on the very edge of the syenite and in a vertical posi- 

 tion, like most of the beds of the same formation along the north- 

 western prolongation of these hills. The conclusion drawn by Mr. 

 Phillips is, that a portion at least of the crystalline Malvern chain 

 was in existence when the Caradoc sandstone was formed, an infer- 

 €!nce which is strengthened by the finer- grained adjacent and regu- 

 larly bedded varieties of the sandstone containing similar minutely 

 triturated, igneous materials. At the same time it is certain, that the 

 great upheavals of the syenite and trappeau rocks took place long 

 after the deposition of the Silurian strata, and even after that of the 

 old red sandstone and coal-measures, which at various points along 

 this ridge, and particularly at the Abberley Hills, have been violently 

 dislocated in contact with such intrusive rocks. The discovery on 

 the west of the Malverns is, however, analogous to what has been 

 observed along the flanks of the granitic axes in the Highlands of 

 Scotland (Ord of Caithness, &c.), where fragments of rocks derived 

 from them are imbedded in the old red sandstone conglomerates, 

 thus showing an original crystalline nucleus, followed by other gra- 

 nitic eruptions. The Isle of Arran offers proof of such a period 

 of activity, which it has been inferred, was posterior to the conti- 

 guous red conglomerate, in which no granitic fragments are im- 

 bedded. 



When he pursues his researches to the northern parts of the 

 .Silurian region, Mr. Phillips will then see, on the flanks of the 

 Breidden Hills, evidences nearly analogous to those which he has 

 so well described in the Malvern Hills, and where it has been 

 shown, that along a very ancient fissure of eruption, molten matter 

 was consolidated before the existence of the Silurian rocks ; that 

 other eruptions followed, and were in continuous activity during 

 the formation of the Lower Silurian strata ; that again other up- 

 heavals took place by the rise of intrusive trap, which threw the 

 previously formed contemporaneous plutonic deposits upon their 

 edges ; that the coal-measures deposited unconformably on such 

 uplifted strata were afterwards deranged ; and finally, that along the 

 very same line of eruption, igneous matter, undistinguishable in- 

 mineral composition from that which had affected the ancient rocks, 

 has cut its way in irregular dykes through the new red sandstone, 

 and, from the isolation of a deposit of lias, was probably ejected 

 subsequent to the accumulation of that deposit*. 



Such facts are, it seems to me, miniature counterparts of the up- 

 raising at successive periods of mountain chains ; and the grand 

 phaenomena of the Caucasus, the Alps, and the Pyrenees may nearly 

 all be studied in our small English ridges, and some of them pecu- 

 liarly well upon the flanks of the Malverns, and their continuation 

 the Abberley Hills. 



In the sequel I shall have occasion to speak oi' other impoi'tant 

 researches of Mr. Phillips. For the present, then, I take leave of 



* See SiUirian System, p. 294. 



