122 Dr. FiTTON on the Strata below the Chalk. 



appears upon the shore on the west of Folkstone, at a point immediately be- 

 neath the church*, which is well marked by the breaking out of a spring-. It 

 is there conformable to the strata described in the preceding sections, and the 

 whole of it has risen to some feet above the sea, on the east of Sandgate, 

 where rocks of the subjacent group (c.) make their appearance on the shore. 

 This second stratum forms the middle of the cliff above and behind the 

 village of Sandgate, but thins off and disappears in the heights on the west of 

 Nail-Down, where some outlying portions of the superior sand {a.) cap the 

 summit of the hills. Its thickness appears to be from 70 to 100 feet: it 

 abounds in green matter, and in some places in pyrites ; from the presence 

 of which substances (though in what manner is not obvious), or perhaps of 

 some portions of clay, it acquires a retentive property ; so that the soil over 

 it is marshy, and ponds are frequent upon its surface. The tracts, therefore, 

 which it occupies, have in some cases in the interior been erroneously sup- 

 posed to belong to one of the beds of clay subjacent to the green-sand. 



(25.) The boundaries of this middle bed, where it is disclosed by the 

 streams having cut through the incumbent sands, are sufficiently indicated 

 on the map. In following up the streams towards Inbrook and Frogwell, the 

 contrast of the two strata is very conspicuous, the junction of this retentive 

 middle group with the sands above being indicated by the breaking out of 

 springs f ; and a line drawn through the heads of the streamlets thus arising 

 would be throughout at distances from the outcrop of the chalk nearly pro- 

 portioned to the inclination of the strata. 



(26.) The presence of this stratum occasions frequent falls of the incum- 

 bent sand beds, and has given origin to an under-cliff covered with vege- 

 tation, which extends from Folkstone to Sandgate. The sections therefore 

 are obscured ; but enough is visible to prove that it contains no prominent 

 beds of stone, and that concretions are comparatively rare in it. Near its 

 junction with the stony strata beneath, the consolidated sand affords several 

 characteristic fossils; and about the middle of the heights over Sandgate];, 

 a line of ferruginous nodules has been found, inclosing fossils, like those of 



" tion, as performed on the great scale in the mineral kingdom, during hundreds and thousands of 

 " years, and with unlimited quantities of the menstruum, might be, and doubtless was, very dif- 

 " ferent." — -'Report of a Lecture on the Chemistry of Geology'; Lond. and Ed. Philosophical 

 Magazine, 1833, vol. iii. p. 24. 



* See the View, Plate VIII. 



t It is not impossible that the site here mentioned may correspond to that of the Sandrock 

 spring, in the Isle of Wight. A ferruginous spring, I was informed, does exist in the vicinity of 

 Sandgate. 



J In the grounds of Encombe, the seat of Mr. Dawkins. The place is indicated in Plate VIII. 



