STRATA OF THE HAMPSHIEE BASIN. 145 



bleau Sands. Hence the distinguished French geologist argued that 

 Colwell-Bay beds are of younger age, and must overlie those of the 

 Headon Hill and Hordwell*. Unfortunately some of the points of 

 correlation insisted upon by M. Hebert in the same paper, were 

 such as could not be accepted by English geologists (and this was 

 forcibly pointed out by Lyell and Forbes) ; thus the really valuable 

 suggestions made by the French geologist came to be altogether 

 neglected by later writers upon the subject in this country. 



Although I was led to the recognition of the true succession of 

 beds in the Isle-of- Wight section quite independently of these ob- 

 servations of Dr. Wright and II. Hebert, it is right to point out 

 how near these geologists were to the true solution of the problem. 

 I may add that I am convinced that although Prof. Edward Forbes 

 argued so strongly against the views of M. Hebert, yet before his 

 death he had begun to perceive tJie difficulties which beset the 

 accepted classification of the Headon beds, and that, had his life 

 been spared to complete that rigid palseontological examination of 

 the lower beds of the fluvio-marine series which he so successfully 

 accomplished with respect to the higher parts of the same series, he 

 would have so modified his classification as to have rendered the 

 publication of the present memoir unnecessary. In Forbes's post- 

 humous memoir the account of the Headon beds occupies only 

 three pages, which are reprinted, almost without alteration, from 

 the memoir read before this Society by the author on the 4th of 

 May, 1853 f. 



If we now proceed to examine the supposed proofs of the exist- 

 ence of a great anticlinal by which the strata at the base of Headon 

 HiU are folded over so as to reappear in Colwell Bay, we shall find 

 that they do not stand the test of careful scrutiny and exact measure- 

 ment. "Webster and other authors following him have well shown 

 how the Tertiary and underlying strata of the Isle of Wight have 

 been subjected to disturbances producing a series of fiexures, the 

 axes of which lie in an east-and-west direction, and which attain 

 their maximum development in the great anticlinal curve stretching 

 from Whitecliff Bay to Alum Bay and thence on to Studland Bay 

 on the Dorsetshire coast. But, in addition to these east-and-west 

 folds, the Isle-of- Wight strata exhibit evidence of having been 

 subjected to another set of flexures, at right angles to the former, 

 and having their axes striking north and south. The positions and 

 effects of this second series of flexures were well illustrated by Prof. 

 Edward Forbes in his memoir read before this Society J. 



Now, from Cliff End to Headon Hill, the coast of the Isle of 

 Wight trends nearly north and south, and we have presented to us 

 in the cliffs a section nearly at right angles to the first-mentioned 

 series of folds. From Cliff End to Warden Point the beds have a 

 steady dip of from 2° to 3° to the north, interrupted only by several 



* " Comparaison des couches tertiaires inferieures dela France et de I'Angle- 

 terre," Bull. Soc. Geol. France, 2« ser. t. ix. p. 191. 



t Quart. Journ. Geol. Soc. vol. ix. p. 259. 

 • X Quart. Journ. Geol. Soc. vol. ix. p. 260, fig. 1. 



