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have detected proofs of the transport of great masses of rock to places and 

 situations to which they do not belong, and where they rest on rocks of an en- 

 tirely different character to their own. 



Let us reflect then upon our country as submerged beneath an ice traversed 

 sea, and gradually lifted by forces acting from beneath through currents assisted 

 by ice action, and earthquake movements acting on certain points and localities 

 with more force than at others. 



Let those who doubt go to the valleys of the Usk and Wye, and observe the 

 upheaval [which has there taken place since this period, as evidenced by the 

 boulders, and there will be little difficulty in accounting for the rifting of the 

 rocks of Symonds Yat along the fault of the Wye Valley, or the perching of rock 

 masses on the external flanks of the Forest of Dean. 



It is difficult to imagine the great denudation and wearing away of rock 

 masses that took place during that long epoch which geologists call the glacial. 

 It was a period that lasted, without doubt, for a long series of ages, and I much 

 suspect that it was during this period that the older (Palaeozoic) deposits, such 

 as the Coal Measures, the Carboniferous Limestone, and the Upper Old Red 

 Sandstone were denuded over those large tracks of Herefordshire, Shropshire, and 

 Monmouth, which are occupied by the Lower Old Red, or the Silurian rocks. 

 The rock masses in the immediate neighbourhood of Ross consist of the Upper 

 Old Red Sandstone and the Carboniferous rocks. The rocks that crown the 

 summit of the Scyrrid, the Sugar Loaf, and even the lofty Vans of Brecon, are 

 the equivalent beds of those deposits which underlie the Mountain Limestone of 

 the Ross district. It is interesting to work out the problems of faults and 

 upheavals which enable us to comprehend this history ; but it requires study, 

 and a personal inspection of the geology of a large district. 



The Carboniferous deposits, such as the Limestone shale, the Carboniferous 

 Limestone, the Millstone Grit, and the Coal Measures, are all present in Dean 

 Forest, and may be all recognised if the different sections displayed in various 

 localities be studied with care. The beds observed to-day are the Old Red Con- 

 glomerate and the Mountain Limestone, the intermediate beds — the yellow sand- 

 stone, and the limestone shale — being masked by debris. These are the rocks 

 which underlie the regular coal seams, sandstones and clays of Dean Forest, and 

 the South Wales coal-field. 



It is impossible on an occasion of this kind to enter into details, or do more 

 than make very broad and general statements. Enough, however, has, I trust, 

 been said to convince the naturalist and archaeologist that there is a large field 

 for research in the neighbourhood of Ross. If there are any present who have 

 not hitherto made themselves acquainted with the history of the rocks, let me 

 advise them to work out the physical geology comprehended within a few days 

 walk or drive from Ross. I have long been an explorer of the geology of Great 

 Britain ; but I do not know any neighbourhood where so much may be learned 



