TRANSACTIONS OF SECTION C. 663 



towards Kirk Michael, until they disappear altogether from the cliffs and the 

 shore, They stand up conspicuously along the ancient shore line extending from 

 Kirk Michael to Ballaugh, Sulby, and Ramsey, commanding the low, sandy, and 

 marshy region which forms the northern portion of the island, contrasting in its 

 tlatness with the lofty rolling Ordovician hills behind, culminating in Sartfell, 

 Snaefell, and North Barule. This contrast is obviously the result of a difference 

 in the physical character of the rocks in the two districts. The problem as to 

 which rocks underlie the glacial strata in the former, which had occupied the 

 author's mind for many years, is now partially solved by the three borings which 

 have heen made under his advice by Messrs. Craine in 1891-4 in search of the 

 Coal-Measures of the Whitehaven field, at the Point of Ayre, at Blue Point, and at 

 Lhen Moar. The boring at Lhen Moar revealed the existence of the Carboniferous 

 Limestone at a depth of 167 feet G inches below the drift. The next bore-hole, at 

 Blue Point, about 4,050 feet to the north-east of that at Lhen Moar, revealed the 

 presence of more than 60 feet of Red Sandstone buried 171 feet beneath the drift. 

 The Red Sandstone in this section is, in his opinion, identical with the St. Bees 

 sandstone, or lowest member of the Triassic formation in the district of the Lakes. 



This conclusion is greatly strengthened by the discovery in the third boring at 

 the Point of Ayre, to the east of the lighthouse, of the Triassic marls with salt, at a 

 distance of a little under five miles from Blue Point. The diamond drill was used 

 from a depth of 452 feet to the bottom. The total thickness of the salt-beds 

 amounts to 33 feet 6 inches, and the bore-hole happened also to intersect a brine run 

 2 feet 6 inches in depth. If this section be compared with that published by Mr. 

 Dickenson of the saliferous marls of Duncrue, near Carrickfergus, it will be found 

 to be practically identical. The same series of salt-bearing m«rls is also worked at 

 Barrow-in-Furness and at Preesal, near Fleetwood. The salt-beds in each of these 

 cases are variable in thickness, and those i)i the Isle of Man are thinner thaa in the 

 other localities. It must, however, be remembered that the Manx boring has not 

 been put down to a sufficient depth to test the true thickness of the salt-field. The 

 discovery is of great theoretical importance, because it links on the deposit at 

 Barrow to that of Carrickfergus, and shows that the Irish Sea was an area in which 

 the salt-bearing Triassic marls were deposited. It points towards the truth of Mr, 

 Dickenson's suggestion that the Cheshire salt-field was formerly continuous with 

 that of Ireland. These marls have .eince been broken up, faulted, and denuded 

 away in many places. It is an open question how far those of the Isle of Man 

 are now continuous under the sea eastwards to Barrow and Fleetwood, and to the 

 north-west in the direction of Carrickfergus. 



All these rocks are buried under a great thickness of boulder sand, gravel, and 

 clay, amounting at the Point of Ayre to 298 feet. To this also must be added the 

 height of the drift hills close by, formed of the same materials, which would give the 

 total thickness as not less than 450 feet in the extreme north. The rocky floor on 

 which it rests dips rapidly to the north-east towards the deeper part of the Irish 

 Sea. 



The discovery of this salt-field is likely to add a new industry to the resources 

 of the Isle of Man. 



3. Strictures on the Current Method of Geological Classification and 

 Nomenclature, loith Proposals for its Revision. By Sir Henry 

 HOWORTH, F.R.S. 



4. On the Pleistocene Gravel at Wolvercote, near Oxford. 

 By A. MoNTGOMERiE Bell, 31. a. 



The section is a typical illustration of a somewhat advanced period of 

 Quaternary time, and in its general features resembles the sections at Hoxne and 

 Bedford, originally published by Sir John Evans, while it is very difierent from 

 the implementiferous beds of an earlier age which are found on the Greensand 

 escarpment of Kent and Surrey. 



