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be observed immerliately below us, has (at Nash, to the N.E. of us) Wenlock beds 

 on its eastern side brought up to meet the downthrow of Ludlow on the western. 

 On the hill of Old Radnor, then, we were standing on beds of the age prior to the 

 Wenlock, being to the westward of the fault first spoken of. These are the Upper 

 Llandovery, or May Hill Sandstone and Conglomerate, above which lies the 

 Woolhope, or Lower Wenlock Limestone. Some notes sent by Mr. Banks to 

 Mr. Moore speak of altered Caradoc Sandstone in the quarry just opposite us 

 at the north-east end of Old Radnor Hill. I was not aware of any exposure of 

 Caradoc beds in this locality. But these are, of course, where you might expect 

 to find them — i.e., below the Llandovery. As this latter approaches the eruptive 

 rocks of Stanner it loses its stratification, and acquires a crystalline character. 

 You saw this in the quarry first visited at Dol-y-hir. Beyond Old Radnor the 

 Wenlock shales succeed as far as the town of New Radnor, to the westward of 

 which Ludlow Rocks occupy the district of Radnor Forest, onwards towards the 

 volcanic district that extends from Llandegley to Builth, with its rocks of 

 Llandeilo and Lower Silurian age. Turning eastward we shall pass, on our way 

 to Kington, over beds of the Ludlow formation till we come to those of the 

 passage between the Old Red Sandstone and the Ludlow at Bradnor quarry : 

 Downton Sandstones and tile-stones. Here portions of the large crustacean, 

 Pterygotus, were found some years ago by Mr. Banks. To concentrate our 

 attention, however, on the particular chain of eruption on which we are standing 

 at this moment. Two inquiries suggest themselves in the consideration of any 

 igneous protrusion ; first, of course, what is the rock composed of, and next, 

 at what period of the globe's history, dating by the appearance of different 

 geologic formations, did the eruption which upheaved it take place? Taking this 

 latter point first, it seems almost quite olear, at least highly probable, that the same 

 subterranean action which uplifted the Caradoc and Lawley caused the volcanic 

 outburst at Stanner and Hanter, and that this occurred when the Passage beds 

 were in process of deposition. Here we have, as we have seen, the lower beds of 

 the Upper Silurian— the Woolhope Limestone — disturbed and altered by the out- 

 burst. At the Caradoc range in Shropshire the equivalents of this Woolhope 

 Limestone do not occur until you get some four or five miles to the eastward, the 

 intervening space being occupied by strata of Caradoc, and anterior, formations. 

 But (mark this), on the western side of the Caradoc Hill, and wedged in between 

 it and the great fault that runs along the valley of Church Stretton, there is a 

 small vertical outlier of Wenlock Limestone. It was through rocks therefore of 

 at least as late an age as these that the Caradoc and its neighbour the Lawley 

 were upheaved — through such rocks, in fact, as Stanner and Hanter burst through. 

 Mr. Banks defines the period of eruption a little more closely. He judges, from 

 the broken and compressed state in which the fossils of the larger mollusca of the 

 Ludlow are found, near Kington, that the volcanic activity took place when as yet 

 the Ludlow rocks were not completely solidified ; and, from the character of the 

 water-worn pebbles and other fragments that are found in the Downton Sand- 

 stones of Bradnor, that these Downton beds were then being laid down. Then, 

 as regards the material of which these hills of Stanner and Hanter are composed. 



