Correspondence — Professor J. W. Gregory. 287 



to Mr. Holmes's conclusion, that the area west and north-west of 

 Carlisle consists of Keuper deposits, is also improbable, the rocks 

 thus identified being the gypseous shales above the Penrith Sandstone. 



C0I£I?-ESF01sriDEITCE. 



THE CAELISLE-SOLWAY BASIN. 

 SiK, — In the discussion on the Carlisle-Solway basin at the 

 Geological Society (Abstr, Proc, No. 958) I omitted to reply to 

 Mr. Lamplugh's argument that the Point of Ayre bore in the Isle of 

 Man supports the identification of the rock at the bottom of the 

 Abbeytown bore as the St. Bees Sandstone. The correlation on 

 which this view is based does not seem to me supported by the 

 evidence. The Point of Ayre bore has been recorded in detail by 

 Mr. Lamplugh (Isle of Man memoir, 1903, pp. 585-6), and he there 

 classed the beds above the St. Bees Sandstone as tlie " Saliferous 

 Marls" and obviously regarded them as Keuper (ibid., p. 291). 

 Mr. Lamplugh's argument depends upon the correlation of these beds 

 with the Gypseous Shales at Abbeytown. As no specimens of the 

 rocks from these bores are available, we can only compare them by 

 the bore records. The following table summarizes the records : — 



The two series agree in being argillaceous members of the red rock 

 series, but the diiferences between the two sets of rocks seem far 

 greater than the resemblances. They both contain some gypsum and 

 salt. But the only salt recorded in the Abbeytown journal is present 

 in a 5 ft. layer of red shale with gj'psum and salt. In the Point of 

 Ayre bore the salt occurred in eighteen beds, which yielded 76 ft. 8 in. 

 of cores of salt, in addition to numerous salt-bearing marls. 



