WOOD AND ROME LINCOLNSHIRE AND S.E. YORKSHIRE. 155 



(or south-eastern) slope of the North Wolds, and has a thickness of 

 upwards of 25 feet, composed of finely laminated sands with included 

 gravels. Resting on this last-mentioned sheet, deeply indented 

 into it, and overlapping it towards the north, occurs the gravel 

 marked/'. This bed is intersected by the cliff for a distance of four 

 miles, and has a thickness varying from 10 to 20 feet. It is com- 

 posed principally of hard chalk debris, derived from the adjacent 

 Wold, with some intermixture of flint and fragments of various 

 rocks, derived probably from the purple clay. This bed (which we 

 may assume was deposited horizontally) rises up towards the Wolds 

 on the north of Bridlington until it attains an elevation of nearly 

 100 feet ; but south of that place, towards Auburn, it descends nearly 

 to the beach ; from which it would seem to follow, as the coast- 

 section is transverse to the sheet, that some inequality in the eleva- 

 tion of these parts took place at so recent a period as that which 

 followed the gravel /'. All the beds belonging to the/ series, although 

 some of them probably are fluviatile, as those at Hornsea, appear to 

 have had their connexion with the sea in the easterly position 

 which it now occupies, and afford the first indication which we meet 

 with of that state of things among the formations that we have 

 been describing. 



Capping all the beds from c to /' indiscriminately (but most fre- 

 quently and extensively resting on the beds of series /) occur nu- 

 merous deposits of white freshwater marl, abounding with Cyclas. 

 That at Hornsea appears to have been the deposit of the mere there, 

 during some earlier, and perhaps historical, period ; and a blue clay, 

 associated with the remains of a forest, occurring on the shore at 

 low water, at Sand le Mere, seems to be similarly connected vrith 

 the former extension of the mere there. Some of these deposits on 

 the higher part of the cliffs may be due to ancient swamps, or may 

 even be the bottoms of dried-up ponds ; but it is very remarkable that 

 some of the white marl of this series is, at Paull Cliff, on the Humber, 

 along with the gravel on which it rests, and apparently with the 

 purple clay below it, thrown into a nearly vertical position ; and the 

 whole accumulation of marl, gravel, and purple clay together is 

 thrown into confusion *. An extensive sheet of this Cyclas marl 

 occurs (resting on the inland extension of the gravel /') at the foot 

 of the eastern Wold- slope to the west of Driffield, along the course 



* A carefal drawing of the spot was made by the first-named of us in 1864, 

 as the progress of the works connected with the battery there was likely to con- 

 ceal the section ; but the well sunk there indicates the same thing, the opposite 

 sides of the well-shaft not according with each other. A similar case exists at 

 the brickfield on the north side of Southwold, in Sufiblk (by the shore), where, 

 in 1866, a similar white marl with Cyclas, resting on several feet of sand and 

 gravel, which rested on the Upper Glacial clay, was, together with the sand and 

 clay, shown to have been thrown into a nearly vertical position. A careful 

 drawing, also, of this section was made by the first-named of us. Can these local 

 disturbances be connected with those greater movements which at a very late 

 period have given rise to the Thames river, as discussed at page 414 of the 23rd 

 volume of this Journal, and to the recent easterly depression of Yorkshire and 

 Lincolnshire to which we allude further on ? or are they due to local subsidences 

 produced by some subterranean percolation of water ? 



