450 STRATIGRAPHICAL GEOLOGY 



The only other part of England where Purbeck Beds have 

 been found is in Sussex north-west of Battle, where narrow strips 

 of them are brought up by anticlinal flexures from below the 

 Wealden Beds. They consist of shales with beds of limestone 

 which were formerly quarried, and the succession proved by shafts 

 and given by Mr. Topley 23 is : 



Feet. 

 Shales with beds of limestone and some of calcareous sandstones, 



Gyp. punctata and 0. granulosa ...... 80 



Black, grey, and greenish shales with ironstone nodules . . 130 

 Bluish-grey limestones and shales, with Oslrea, Cardium, Cyrena, 



and other fossils ......... 75 



Shales with many beds of gypsum ....... 130 



415 



Purbeck Beds have also been traversed by many of the borings 

 which have recently been made in Kent, and the records show 

 that the group thins both to the north and east. Thus at Pluckley, 

 about 16 miles north-east of the outcrops in Sussex, they are 

 only 100 feet thick, arid at Brabourne, about 10 miles farther east, 

 they have diminished to about 60 feet. They were not found in 

 any of the borings to the north or east of that place, though this 

 may be due to the planing off of beds below the Vectian sands. 



D. THE UPPER JURASSIC SERIES IN SCOTLAND 



"West Coast. The only member of the Upper Jurassic 

 series which is found on the west coast of Scotland is the Oxford 

 Clay. This overlies the great estuarine series in the islands of 

 Skye and Eigg, and consists of blue clays containing Cardioceras 

 cordatum, Card, excavatum, Quenstedticeras Lamberti, and others. 

 Above it are Cretaceous rocks. 



East Coast. In Sutherland a much more complete series is 

 found ; the beds are seen at intervals along the coast for a distance 

 of 16 miles, and form a narrow strip of low ground which is 

 bounded inland by a powerful fault, and has an extreme width 

 near Brora of about 2 miles. In this small space is found 

 a succession of beds representing the whole of the Oxford Clay, 



Coral Rag, and part of the Kimeridge Clay, as below : 



Feet. 



Light-coloured sandstone ; no fossils .... 100 

 Shelly limestones, black shales, and grits with Belem- 

 nites abbreviatus, Cardioceras alternans, Perisphinctcs 



Kimeridge 

 Clay 



biplex, and many others ; ferns, cycads, and conifers 500 

 White sandstones aud carbonaceous shales ; estuarine 



beds with few fossils ...... 200 



Grits and sandstones ; Perisphinctes biplex, Per. muta- 



bilis, Heineckia eudoxus, and Belemnites obeliscus . 1 200 



