Dr. FiTTON on the Strata beloic the Chalk. 107 



and on the shore there are numerous detached masses^ composed of round 

 portions of grey marly chalk united by a yellowish-brown cement. The shore 

 itself, at this place, is a firm floor of light bluish grey marl, the beds beneath 

 beins- of a still darker hue. The vertical face of the cliff retires from the sea 

 about 2000 paces west of Lydden Spout; and the intermediate shore, thence 

 to Copt Point, is occupied by a mass of ruin, which has fallen from above, 

 in consequence of the rise and erosion of the soft argillaceous beds beneath. 

 The sudden transition to this ruinous under-clifT from the vertical face of 

 chalk is very remarkable. A stratum abounding' in green particles, intimately 

 mixed with marl, appears at low water, in several detached places on the 

 shore west of Lydden Spout, and is succeeded by the blue clay of the gault, 

 which continues to Copt Point, where it rests upon the sand and grit of lower 

 green-sand : — the prominence of the Point itself, and of the shore to the west 

 of it, being evidently produced by the greater firmness and durability of the 

 latter stratum. 



The succession of the beds is best seen in the retiring portion of the shore, 

 immediately on the north of Copt Point, (see Plate X a. No. 1.) A small outlier 

 of the lowest chalk, with green-sand beneath it, is there exposed at the summit 

 of the rounded hill on which stands the Martello Tower No. 3. Copt Point 

 itself consists almost entirely of gault, which tops the low cliff thence to the 

 village of Polkstone. The lower green-sand, rising gradually from the Point, 

 occupies the whole cliff west of the village; and being continued without in- 

 terruption, through Sandgate and in the heights above Hythe, its outcrop turns 

 from the coast into the interior, at Aldington Corner. Finally, the Weald- 

 clay, rising on the shore beneath Shorn Cliff, occupies the greater part of the 

 heights and sloping ground on which the town of Hythe is placed, and ex- 

 tends about four miles farther to the west, where it gives place to the 

 Hastings-sands. 



In my obervations on this part of the coast, I shall confine myself to the 

 beds below the chalk ; referring for a detailed account of that stratum to 

 Mr. W, Phillips's paper, already mentioned. 



(9.) Upper Green-sand. The upper green-sand near Folkstone, is but 

 a scanty representative of the formation, as it occurs in the Isle of Wight, 

 Surrey, Western Sussex, and some other places in the interior ; its total 

 thickness probably not exceeding five-and-twenty or thirty feet, and the stony 

 strata and concretions of chert being altogether wanting. Its rise upon the 

 shore is concealed ; and the stratum is first seen in its proper situation be- 

 neath the Martello Tower No. 2. A small outlying portion about fourteen 

 feet in thickness, occurs beneath a cap of grey chalk marl about eight feet 



p 2 



