406 MR. s. s. BUCKMAX OX [vol. Ixxviii, 



not at Down Cliffs nor at Watton Cliff ; this implies slight syn- 

 clination of the Thorneombe area at the time of post-Marlstone 

 denudation, just sufficient to preserve the thin bed. But there 

 was a pre-Marlstone denudation — the presence of big blue 

 sandstone-pebbles in the marlstone of the Junction-Bed of 

 Thorneombe Beacon is evidence for that. The matrix of these 

 pebbles suggests that the}'" come from the Starlish-Bed ; they 

 certainly did not come from the margaritatus bed. Taking the 

 data of denudation ascertained in the above sections — that is, about 

 30 feet to a mile, — then the Starfish-Bed was elevated to the line 

 of erosion some Og miles from Thorneombe Beacon. The main axis 

 of the Weymouth Anticline runs out to sea some 7 miles south of 

 Thorneombe Beacon. Another mile and a half would involve a 

 further 45 feet, wdiich would be insufficient to bring the Three 

 Tiers — the next hard bed — to the surface alons^ the axis. 



The fact that the margaritafus bed is not found in pebbly 

 condition, while the TetrarJiipicliia-tliorncomhiensis Bed is found 

 as pebbles in Watton Cliff (and probably it is the Starfish-Bed 

 that furnished the pebbles for the Junction-Bed of Thorneombe 

 Beacon), may suggest that movements of 'post-mcnyarifafus-hed 

 time allowed that bed to be covered up and protected by tliorn- 

 comhiensis or 'pve-tJior)ico)nhie]?sis-hed deposits. 



It will thus be seen that the Watton Bed is a deposit of excep- 

 tional interest geologically : it would also be rich palseontologically, 

 if one had the means of breaking up the massive blocks. That it 

 is different from the Thorneombe Beacon Junction-Bed, only about 

 7 furlongs away to the west, is due to the fact that it really belongs 

 to a different piece of territory — to what was some half-mile 

 nearer the anticlinal axis. This little transverse difference is more 

 important than a considerable lateral distance, as is shown by the 

 similarity of the Down Cliffs (Thorneombe) and Bothenhampton 

 Junction-Beds, which are from 2^ to 3 miles apart, but along the 

 same line of fold. 



The movements of the Weymouth Anticline and the distribution 

 of strata which they produced in the English Channel suggest 

 an interesting line of enquir}' — as to the present-day distribution 

 of strata out to sea. Some 20 v^ears ago I collected certain data 

 on the subject ; but there has not yet been any opportunity of 

 working out details, and the enquiry must be deferred for the 

 present. However, such an enquiry should have a certain prac- 

 tical bearing. The distribution of areas of hard rocks — that is, 

 areas of sandstone or limestone — is important to fishermen, as 

 affording good ground for the setting of their lobster-pots. A 

 geological investigation should indicate likely places to sound for 

 such areas, and might lead to the discovery of some which are not 

 yet known to the fishermen : they had, at the time I speak of, just 

 made a chance discovery of a new ground. 



To return to the Junction-Bed — it is evident from the various 

 sections that the Weymouth Anticline was in a state of constant 

 m.ovement with consequent denudation making non-sequences. 



