]859.] HULL TBTTXNTNG-OITT OF THE SECONDARY ROCKS. 77 



been elevated into a marginal coast at the commencement of the 

 Kcupcr period ; and this would have necessarily produced a certain 

 degree of unconformity between these two formations of the Triassic 

 Series. 



The relative position of the Buntcr and Kcupcr in Leicestershire 

 appears to afford evidence of unconformity. The conglomerate-beds 

 of the Eunter are confined to the western and northern portions of 

 the Ashby-de-la-Zouch Coal-field, where they attain a thickness of 

 200 or 300 feet. Along a line passing N.E. and 8.W. through 

 Moira they terminate abruptly ; and east of this line we find the 

 Lower Keuper Sandstone resting immediately on the Coal-measures. 

 These conditions would seem to indicate, — first, that after the de- 

 position of the conglomerates certain disturbances had occurred, 

 elevating the south-eastern districts, and thus causing the denu- 

 dation of the conglomerates from oft* that area ; and, secondly, that, 

 after these disturbances (involving, of course, an imconformity), the 

 beds of the Keuper had been deposited where we find them, resting 

 on the conglomerates of the Bunter in one direction and on the Coal- 

 measures in the other. 



In Lancashire, near Ormskirk, there is a section showing the 

 superposition of these formations, in which the appearance of un- 

 conformity is of so satisfactory a nature that it elicited the assent 

 of such a cautious observer as Professor Ramsay. As the geology 

 of this district has not yet been published by the Geological Survey, 

 I do not feel at liberty to describe this section, but will only add 

 that it is seldom that a more evident case of unconformity is laid 

 open to view. 



In thus stating my conviction that these formations are uncon- 

 formable, I by no means wish to assert that the non-parallelism of 

 the beds is ever very great ; it is only sufficient to prove that dis- 

 turbances and denudation have intervened between the two periods 

 one effect of which was to place the bed of the Bunter Sandstone 

 Bea beyond the reach of marine deposition, and thus account for the 

 entire absence of the Muschelkalk in England. 



I shall close this subject, which I feel I have very imperfectly 

 treated, with one more remark. It is scarcely possible to estimate 

 the advantage, both to science and to civilization, which lias resulted 

 from the present ei m figuration of the Mesozoic rocks of England. 

 Keeping is mind the tendency which they exhibit to thin away 

 towards the south-east, it is evident that, with their present strike 

 and inclination, they are presented to us in succession along lines () f 

 fullest development. In order to estimate this more fully, we have 

 only to refl.it how dwarfish would have been the ascending series 

 of formations, had they been upheaved along an axis coinciding with 

 the present eecarpmenl of the chalk from i;< .nliiitr to the German 

 Ocean. Such an arrangement would also have shut out all hope of 

 reaching coal in the central counties, as the Carboniferous rocks 

 would have been covered by the newer formations over the regions 

 of their greatest vertical thickness. 



