KENT, NORFOLK, ETC. 21 



the firestone resting on the gait, and over all the 

 lower and upper chalk formations. 



Continuing our journey along the Kentish coast, 

 we arrive at the London Clay, a Tertiary deposit 

 of great thickness, being in some instances 600 

 feet in depth, and covering a very wide area, 

 extending from the eastern shores of Kent to the 

 chalk hills of Wiltshire, Berkshire, Oxfordshire, 

 Buckinghamshire, and Hertfordshire toward the 

 west, and northwards to the extreme limits of 

 Norfolk. This deposit, on which the metropolis 

 of England stands, formed in some remote era 

 the bottom of a gulf of the ocean, and, like the 

 various strata already noticed, constitutes an 

 object of the deepest interest to the geologist, from 

 the abundance of organic remains which it dis- 

 closes. Of this clay the Isle of Sheppey is 

 entirely composed. 



On the northern shores of the county of Norfolk 

 the Cretaceous formation is again manifested, and 

 from this point along the coast of Lincolnshire 

 and beyond the Humber into Holderness the coast 

 line is chiefly made up of low cliffs of gravel, 

 marine detritus, and tertiary deposits. The 

 promontory of Flamborough Head, which we now 

 reach, is formed of chalk, to the north of which 

 the coast boundary is formed of various members 

 of the Oolite and Lias formations. From the 

 river Tees to Tynemouth the trias deposits and 

 the magnesian limestone of the Permian system 

 occur, and beyond this point to Berwick the coast 

 is formed by the Carboniferous system, interrupted 



c 3 



