318 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 3, 



of the chalk and Mewp Bay on the west, of which I only visited the 

 former. 



" The Hastings sands of Worbarrow Bay consist of a considerable 

 admixture of clays and sandstones. The latter appear to abound 

 here more than at Swanage Bay. The clays possess the peculiar cha- 

 racter and colours of those at Bidgway, but some of their colours 

 are rather more vivid. The colour of the sandstones, from the great 

 abundance of the ferruginous base, is in many places intense. I 

 could not discover any organized remains in these clays. I think 

 no one who has examined this part of Dorset, and has traced the 

 base of the chalk escarpment from Ballard Down to Purbeck Hill, 

 can fail to be convinced of the correctness of Dr. Fitton's view, and 

 to feel satisfied of the continuity of the Wealden formation right 

 across the peninsula of Purbeck." 



He next visited Lul worth Cove, where the general appearance of 

 the Hastings sand is similar to the localities we have already de- 

 scribed. Not far from this place is the last coast exhibition of the 

 Wealden formation in Man-of-War and Durdle Coves. These are 

 separated from each other by a short isthmus, which has been pro- 

 tected by a rock of greatly-inclined strata of Purbeck stone, and is 

 composed of the Wealden very condensely and vertically developed. 

 From this isthmus we see the eastern side of Man-of-War Cove, 

 which appeared evidently to consist of Hastings sand. That point 

 and the isthmus are clearly the remnants of a once continuous mass. 

 The west side of Durdle Cove is composed of chalk which here abuts 

 upon the sea, and runs uninterruptedly along the coast to the high 

 point of White Nore, whence it trends inland. 



In all these sections the variegated clays, loams and sands were 

 identical in character with the Ridgway deposit. In this section, 

 which he visited the following day, Mr. Weston "traced the Purbeck 

 beds to their first uninterrupted termination, which consisted of calc 

 grit with Purbeck fossils. Beyond this were clays, and then alter- 

 nations of the calc grit and clays, and ultimately the Hastings bed 

 exclusively. This section therefore exhibits the same features which 

 Dr. Fitton has observed respecting other sections of the Wealden, 

 showing, 1 st, the continuity and sequence in the deposition ; and, 

 2ndly, the quiet process of such deposition. Hence we have the 

 most satisfactory evidence that the beds overlying the Purbeck fol- 

 lowed in regular succession, and were in fact rather a continuation of 

 them." 



On the whole Mr. Weston concludes not only that the variegated 

 clays of Ridgway Hill really belong to the Hastings sand formation, 

 but that their geognostic position is in the lowest part of the Worth 

 and Tilgate group, separating it from the inferior Ashburnham 

 beds. 



Mr. Weston also mentions that he found the Purbeck deposits to 

 extend as far west as the end of the Corton Range, and therefore 

 spreading co-extensively with the Portland oolite to the vicinity of 

 Portisham. 



In regard to the attempt to explain the singular interposition of 



