LOWER GREENSAND. 365 



of the Cowleaze series are used locally for rough paving. Mr. C. 

 J. A. Meyer regards the Punfield Beds of the Isle of Wight as 

 essentially part of the Wealden formation. (Seep. 357.) 



In Dorsetshire the Wealden Beds are represented by alternations 

 of red and purple coloured clays, white and yellow sands, and 

 occasional beds of quartzose sandstone or grit, with lignite towards 

 the base. The occurrence of this lignite on the foreshore gave 

 rise to the notion of a submerged forest in Swanage Bay. (See 

 Fig. 54, p. 347.) In Swanage Bay the thickness of the beds has 

 been estimated at 1800 feet; at Worbarrow Bay 725, at Mewps 

 Bay 660, at Lulworth Cove 462, and at Man of War Cove 172 

 feet, showing a remarkable attenuation of the beds which takes 

 place towards the west ; but this may in part be due to faulting, 

 for at ]\Iewps Bay the Wealden Beds are faulted against the 

 Greensand, etc.^ The Wealden Beds occur at Ridgway,- and they 

 are also to be seen at Dinton, west of Wilton, where fragments of 

 Endogenites erosa have been obtained by the Rev. W. R. Andrews. 

 (See p. 348.) 



In Oxfordshire the lower portions of the Iron-sands of Shotover 

 contain freshwater shells, and by some authorities the beds have 

 been grouped as Wealden, but they are now usually regarded 

 as Lower Greensand. (See sequel.) 



In Lincolnshire the Wealden Beds are represented in part by the 

 Spilsby Sandstone. (See Fig. 62.) In Yorkshire the Speeton 

 Clay contains marine representatives of the Wealden Beds, and 

 Prof. Judd has traced beds of this age at Reighton, West Heslerton, 

 and Knapton in the Vale of Pickering.^ (See sequel.) 



LOWER GREENSAND. 



Among earlier writers much confusion arose between the Iron- 

 sands of the Wealden series and those of the Lower Greensand ; 

 the latter term was, however, proposed by Webster in 1824, and 

 finally came into general use, though not without protest from 

 Fitton in 1827, and from other geologists at various subsequent 

 times.* 



Although the term Lower Greensand is in many respects unsatisfactory, it is so 

 well known that more inconvenience is likely to arise from a change of name than 

 by adhering to Lower Greensand, even if the distinction between it and the Upper 

 Greensand is greater than the terms would seem to imply. The name Vectian, 

 recommended in 18S5 by Mr. A. J. Jukes-Browne, was previously applied by 

 John Phillips to the Fluvio-marine Tertiary Strata of the Isle of Wight,^ while 



1 Judd, Q. J. xxvii. 222 ; J. C. Mansel-Pleydell, G. Mag. 1873, p. 410. 



* C. H. Weston, Q. J. iv. 245, v. 317. 

 "" Q. J. xxvi. 326. 



* See Judd, G. Mag. 1870, p. 223, 1886, p. 384; Topley, Geol. Weald, p. 15. 

 ^ Guide to Geology, edit. 5, p. 199. 



