46 Correspondence — Mr. J. R. Dahyns. 



THE CALDER VALLEY. 



Sir, — Mr. Davis's paper on the Valley of the Calder, in the 

 number of the Geol. Mag. for November, 1878, is sure to be widely 

 read ; but I fear that some points in it are likely to be misunder- 

 stood by beginners in the study of geology. This must be my 

 excuse for troubling you with any remarks on it, and I trust 

 that my friend, the author, will for the same reason forgive any 

 criticisms of mine. 



Take the following sentences with reference to the Pennine Anti- 

 clinal and Blackstone Edge, viz. : " The thick beds of gritstone and 

 shales were crumpled up like the leaves of a book, but being of a 

 hard and very inelastic nature, the grit rocks were broken asunder, 

 and we have the two faces of the separated rock considerably apart, 

 in some instances the distance has to be reckoned by miles ; " and 

 again, "As the strata were successively strained and broken, they 

 would gape wide apart at the centre of the arch ; each bed of sand- 

 stone or shale, as it became elevated to the surface, would carry those 

 which had preceded it further and further from the centre of rupture." 



I think that these remarks are very apt, as they stand, to mislead 

 young students into thinking that the opposing escarpments of each 

 bed of grit, etc., as shown in the diagram, once touched each other 

 along their present faces ; and that the vacant spaces represent a 

 gaping fissure instead of so much material removed by denudation. 

 Of course, Mr. Davis does not mean this, but I fear that many 

 readers will think he does. 



Again, with reference to Stainmoor and the transport of granite 

 boulders, we read that a branch of the great glacier "passed over 

 Stainmoor into Wensleydale." Now, the pass of Stainmoor does not 

 lead into Wensleydale, but into Teesdale. Wensleydale must have 

 been written by mistake for Teesdale. But further, there are no 

 granite boulders in Wensleydale. The whole discussion as to the 

 transport of Shap granite boulders into East Yorkshire turns upon 

 the fact that they did not travel by way of Wensleydale, but crossed 

 over the lofty pass of Stainmoor, and that at such an elevation that 

 there was nothing to prevent their also getting into Arkendale, and so 

 into Swaledale, had they gone over on floating ice, as so many 

 geologists have maintained. With reference to this I would refer to 

 Mr. Goodchild's map and paper on the " Glacial Phenomena of the 

 Eden Valley" (Quart. Journ. Geol. Soc. 1875, vol. xxxi. p. 55). 



I do not know what river base Mr. Davis refers to as being "not far 

 distant " from the Calder Valley ; but, as to the latter valley having 

 been submerged when the erratics found in its gravel, were trans- 

 ported thither, I wish Mr. Davis would give us his reasons for so thinking. 



It would be a very interesting fact were it established or even 

 rendered probable that the Calder Valley was submerged when its 

 gravels were deposited ; but I should like to hear the reasons for it 

 before accepting it. The said gravels did not appear to me, when I 

 was working in that country, to differ from ordinary river gravels; nor 

 do I think it at all necessary to introduce the sea to account for the 

 erratics found in those gravels ; for the glacial drift with erratics 



