148 UPPER, OR FLINTY CHALK. 



But to return from this digression.— The line of coast from Brighton 

 to Beachy Head, exposes an interesting vertical section of the upper chalk, 

 exhibiting almost every variety of character hitherto remarked in the 

 beds of that deposit. 



At Brighton, the cliffs are composed of an accumulation of diluvial 

 substances, resting upon the sohd chalk, which there constitutes the sea- 

 shore, and continues to Eottingdean. From thence to Newhaven, the 

 cliffs are nearly perpendicular, and on the western side of the harbour 

 rise into an irregular elevation called Castle hill, the upper part of which, 

 is composed of numerous beds of the plastic clay formation : the lowermost 

 fifty feet consisting of the flinty chalk. On the opposite side of the river, 

 a low mound of chalk, capped with a bed of plastic clay and ferruginous 

 breccia, appears at Chimting Castle. Proceeding eastward towards the 

 Signal-house, near Seaford, the chalk rises to a considerable height, and 

 forms a majestic hne of chffs from thence, to the embouchure of Cuck- 

 mere river ; from this place they extend eastward, and terminate in the 

 magnificent promontory of Beachy Head, which is nearly six hundred feet 

 above the level of the sea *. Along this line of coast, Ammonites of a 

 large size, Plagiostomae, Terebratulas, Echinites, and other productions 

 of the chalk, may be obtained in considerable numbers. 



The sections in the interior of the country are entirely artificial ; of 

 these, the following are the most interesting, that occur in the south- 

 eastern part of the county. 



the corresponding mould of the pin so laid bare ; he presented them to Thomas Blacker, Esq. 

 in whose possession they now are, and who has shewn them to the writer of this paper." 



In the Gentleman's Magazine for 17 — , mention is made of an ancient brass key (a figure 

 of which is there engraved) having been found in a block of chalk at Guilford, in Surrey. 

 My friend, J. B. Durrant, Esq. of Mailing-house, had the kindness, in compliance with my re- 

 quest, to inquire into the correctness of the account, but it proved, as indeed might have been 

 expected, too apochryphal to be worthy of credit. 



* The following circumstance is too singular to be omitted. One of those prodigious 

 falls of the chalk cliffs, which make a residence near them frequently so dangerous, oc- 

 curred at Beachy Head a few years since. The clergyman of East Dean was walking on 

 the brink of the precipice, when he perceived the ground to be sinking from under him, 

 and although he had the presence of mind instantly to rush from the impending danger, a 

 deep chasm had formed at some distance from the edge of the cliff, over which he had escaped 

 but a few moments, before the mass of chalk upon which he had been standing, to the extent of 

 three hundred feet in length, and eighty in breadth, fell with a tremendous crash into the. sea. 

 Geological Transactions, Vol. ii. p. 191. 



