THE RIDGWAY FAULT. 59 



their paper in the Transactions of the Geological Society on the 

 Geology of the Neighbourhood of Weymouth. They recognised 

 the importance of the district on the following grounds : 



1. Its position near the south-western termination of several 

 principal formations of the island, including Tertiary strata, chalk, 

 greensand, Purbeck and Portland beds, oolitic formations, and Lias. 



2. As exhibiting a coast section forming an interesting 

 comparison with the equivalent north-easterly terminations of the 

 same strata on the Yorkshire coast. 



3. As affording remarkable examples of violent disturbances, 

 which have affected all these strata since their consolidation, and 

 which have operated so extensively in Purbeck and the Isle of 

 Wight and the "Weald of Kent and Sussex. 



Further, they pointed out the existence of an anticlinal axis, 

 running in an east and west line near the sea, and denned the 

 limits of the Ridgway Fault as well as the existence of four other 

 faults of much smaller magnitude in the district. This, then, I 

 think we may consider as the classical contribution to the subject. 

 It was followed by two contributions to the Journal of the 

 Geological Society for the year 1848, by Mr. C. H. Weston, entitled 

 " The Geology of Ridgway, near Weymouth," and "Sub-escarpments 

 of the Ridgway Range near Weymouth and their Contemporaneous 

 Deposits in the Isle of Portland." Mr. Whittaker, in his paper in the 

 Geological Society's Journal for 1871, traced the gradual thinning 

 out of the Lower Chalk and Chalk Marl from the Isle of Wight 

 westwards, so that at Bere Head the Upper Chalk is found almost 

 resting on the Upper Greensand, separated only by the Bere rock, 

 the representative of the Lower Chalk. Mr. Osmond Fisher, 

 whose name is chiefly identified with investigations into mathe- 

 matical problems connected with geology though this evening at 

 Burlington House he is occupied with the description of the Fossil 

 Elephant lately found near Dewlish also contributed his share to 

 the elucidation of this district as we have seen from the model 

 of the Ridgway Fault constructed and placed by him in the County 

 Museum. He tells me that in a publication " Barnes' Guide to 



