64 THE RIDGWAT FAULT. 



raised above its own level by local pressure. In a note he gives 

 the following figures : " The finished line of railway cutting is 

 about 247 feet above the level of high floods at Weymouth, and 

 the shaft sunk from the surface to the level is about 50 feet. 

 Hence the Oxford clay at this spot inust be about 300 feet higher 

 than that near "VVeymouth." 



The Osmington Fault runs also in an east and west direction, 

 parallel to the Ridgway Fault at the distance of about 1 J miles to 

 the south. Its western termination is visible at Hamcliff. At 

 Upton Hill horizontal chalk beds form the north side of the 

 dislocation, whilst subsided chalk, green sand, and Portland stone 

 form the south side of the fault. The Ringstead Bay Fault is of 

 very minor importance, and is of very local extent, in fact it is a 

 mere fracture in the section exposed in the cliffs, and has no effect 

 on the chalk formation itself, and though no doubt it may be 

 considered as resulting from the same cause which produced the 

 larger dislocations, its effect is to bring a subsided mass of 

 Portland sand and Portland stone into contact with the Kimmer- 

 idge clay. 



The BotJienhampton Fault is a downcast fault occurring about 

 one mile south-east of Bridport. It was apparently first noticed by 

 Professor Sedgwick. It is of considerable depth, bringing the 

 Forest marble on its south side into contact with the superior Oolite 

 on the north side. The Forest marble dips at a considerable angle 

 towards the fault. Its course is east and west parallel to the 

 others, and in the eastern direction it continues to Shipton Gorge, 

 Litton Cheney, and Long Bredy. 



The Bridport Fault is a downcast fault in the cliffs a mile to the 

 west of Bridport Harbour. The amount of disturbance caused by 

 it is great. On its north side are beds of superior Oolite based on 

 Lias ; on the south side are beds of Forest marble based on more 

 than 150 feet of grey clay, which are violently turned up when 

 they come in contact with the fault. The eastern extremity of 

 the fault presents a complicated double fracture. 



We must now, before bringing this matter to a conclusion, say a 



