260 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



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have been published treatmg 

 of the strata under considera- 

 tion, it might seem that httle 

 new could be made out respect- 

 ing them except concerning mi- 

 nute details. I certainly went 

 to my work expecting to find 

 an easy and speedy task, and it 

 may seem almost like presump- 

 tion when I state as the general 

 result, that not only was the 

 duty to be done far more labo- 

 rious and novel than could have 

 been looked for, but that the 

 geology of the district under 

 consideration had been, in great 

 part, seriously misunderstood 

 by all who had explored it. 



The interpretation usually 

 hitherto accepted of the struc- 

 ture of that part of the Isle of 

 Wight composed of fluvio-ma- 

 rine Eocenes, constituting the 

 greater part of the island north 

 of the great chalk ridge, is that 

 the series of beds exposed in the 

 section of Headon Hill, and con- 

 stituting the Headon Hill sands. 

 Lower freshwater. Upper ma- 

 rine, and Upper freshwater of 

 Webster, includes the whole 

 thickness of the fluvio-marine 

 Eocenes, and that the greater 

 part of the superficial area is 

 occupied by the Lower fresh- 

 water division. This view, which 

 originated with Professor Web- 

 ster, was supported and main- 

 tained in detail by Professor 

 Sedgwick, and has been adopted 

 by most subsequent writers. 



Two geologists only have sur- 

 mised the existence of higher 

 beds than those of Headon, 

 viz. Mr. Prestwich and M. Hu- 

 bert. The former, in 1846, de- 

 scribed briefly the strata com- 

 posing a part of Hempstead Hill 

 to the east of Yarmouth, and 

 suggested that those beds pre- 



