BRITISH ISLES. 19 



groynes, aad notes the occurrence of a " submerged forest " along the 

 sea-line. The various beds are then described, beginning with the 

 newest, the silt of the Brighton valley, which is inferred to have been 

 deposited in an estuary ; the flotation of large stones by seaweed is here 

 noticed. The next bed is the Post-Pliocene brick-earth of Hove, the 

 materials of which the author thinks were derived from the denudation 

 of the older Tertiary formations. The last deposit noticed is the 

 *' elephant-bed " or " combe rock," also of Post-Pliocene age, which 

 consists of fragments of chalk and flints, with some other stones, about 

 50 feet thick, and is underlain by an old sea-beach and sand. The 

 combe rock is inferred to have been deposited gently under water, in a 

 shallow bay or estuary. "W". W. 



HuDLESTOif, Wilfrid H. The Yorkshire Oolites. Part I. Proc. 

 Geol. Assoc, vol. iii. no. 7, pp. 283-333, 8 woodcuts (sections). 



The district described is high land in the N.E. part of the county, 

 with escarpments on the west overlooking the Triassic plain, and on 

 the east bounded by the sea-cliff's. The beds, as a whole, are sandy, 

 pure limestone being rare ; but there is great diff'erence between the 

 coast section and the inland sections, the sandy and clayey lower beds 

 being thickest to the N.E. ; whilst the limestone -beds are, as a rule, 

 thickest to the S.W. The general shape of the ground and the lie of 

 the beds is described, and the connexion of the two noticed. 



In the Lower Oolites there are four fossiliferous zones, best developed 

 on the coast — " Dogger " (lowest), " Millepore Bed," *' Scarborough 

 Limestone," and " Cornbrash." The Blue Wyke Point section is de- 

 scribed in detail, showing, below the Dogger, " yellow sands," " grey 

 sands," and " Striatulus beds." The chief fossils of each are noticed. 



The Dogger, which has a maximum thickness of 80 feet, as a whole 

 is a sandy ironstone, partly oolitic in structure. There are in it nodules 

 of a phosphatic character ; and in some cases the ironstone has been 

 formed through the replacement of lime by iron. In llosedale the 

 Dogger and associated beds have been largely worked for iron, the 

 " magnetic ore " containing over 48 per cent, of metallic iron, peroxide 

 and protoxide in about equal proportions. 



The "lower shales and sandstones" come next (ascending), and reach 

 a thickness of 280 feet. 



The Millepore-bed is sometimes a ferruginous sand rock with bands 

 of ironstone, poor in lime ; but in other parts it contains limestone. It 

 is up to 43 feet thick. 



The " middle shale and sandstone " which succeeds is the principal 

 carbonaceous series of the Lower Oolites, and reaches a thickness of 

 100 feet. 



The Scarborough Limestone consists of marine and cstuarine beds, 

 up to 50 feet thick, with shale (calcareous or not) and ironstone. The 

 sections at Ilundale and White Nab are described in detail. 



The " u})per shale and sandstone" is the next division, with a thick- 

 ness varying up to 100 fc<)t, and contains much hard siliceous rock. 

 Its fossils arc cstuarine snd freshwater; and in the crevices of the 



c2. 



