239 



CHAPTER XIV. 



DISTUEBANCES AIND FAULTS. 



Of the movements of the strata which produced the ahnost 

 unique geological features of the Isle of Wight, the most marked 

 was that which brought the Chalk up in a nearly vertical position 

 in the central range. The fold of the strata thereby effected is 

 found, however, on close examination to consist of two separate 

 anticlinal axes, the one dying out as the other increases ; Avhile 

 other lines of lesser disturbance run neai'ly parallel, each having 

 its influence on the structure of the Island. 



Before describing in detail the various folds observable in the 

 Isle of Wight we will briefly notice the great series of nearly 

 parallel anticlinal and synclinal axes of the south and south-east 

 of England, of which they form part. These axes, taken in order 

 from north to south, are as follow : — 



1st. The great syncline of the London Basin, which extends 

 from Marlborough in the west, and is lost under the German 

 Ocean to the east. 



2nd. The great anticline of the Weald of Kent, which com- 

 mences in the west as two separate anticlines, the one near 

 Devizes, the other near Petersfield, passes under the English 

 Channel, and terminates about 14 miles east of Boulogne. 



Srdly. The syncline of Chichester, which passes north of Ports- 

 down to the sea near Worthing, and eastwards along the coast 

 by Brighton. 



4thly. The anticline of Portsdown and High Down, which runs 

 under the sea at Worthing. 



5th. The syncline of the Isle of Wight, which runs from near 

 Dorchester in the west through the Tertiary area of the Island 

 and out to sea near Brading. 



6th. The double anticline of the Isle of Wight, which com- 

 mences oiF the coast of Devon, strikes the shore near Weymouth, 

 runs along the Dorset coast near St. Albans Head, throuo-h the 

 Cretaceous area of the Isle of Wight, and out to sea near San- 

 down. 



These axes are not strictly parallel. The London axis, for 

 example, runs a little north of east ; the Weald axis curves round 

 considerably south of east in its eastern part ; the Chichester 

 and Portsdown axes are nearly parallel to that of the Weald, but 

 are inclined a little more to the south ; while the synclinal axis. 



