122 



NOTES ON THE DBIPT DEPOSITS 



but as we find that the sandy, gravelly, and clayey strata of 

 the deposits have little to do with the occurrence of the fossils, 

 probably the beds on and near the flanks of the Pennine 

 chain may have been formed under conditions in some way 

 less favourable to organic life, or else the shells of the 

 mollusks of the then existing shells have been more fre- 

 quently destroyed than those deposits more remote and lying 

 near the present sea.* 



Few places in Lancashire present greater facilities for study- 

 ing the drift deposits, especially that part of them known by 

 the name of the " Till," than the cliffs lying between Black- 

 pool and Rossall, but up to this time little information upon 

 them has been given to the public. 



At p. 127 of the Rev. William Thornber's " History of 

 Blackpool" is the following note, where that author, speaking 

 of what he calls "that immense congeries of diluvium," states, 

 " This marly deposit has never been perforated, the late 

 attempt to find coal at Poulton Breck having failed, after 

 boring 179 yards through marl commixed with gypsum, 

 intersected at times with loamy sand and gravel." f This 

 description is somewhat confused, but the beds of gypsum 

 give pretty good evidence that other strata than those of 

 the drift, or as the writer terms it, the diluvium, were 

 penetrated. The beds of marl, loamy sand, and gravel, 

 would appear to shew that the till and lower gravel had 

 been met with, but, as gypsum is mentioned, it clearly 

 shews that either the upper red marls of the trias, or 

 the lower red marls of the permian, similar to those lying 

 above the magnesian limestone, and below the upper new 



* Since this paper was written, Mr. J. F. Bateman, Mem. Inst. C.E., F.G.S., 

 has informed me that in making the Ilollingwortli reservoir, near Mottram in 

 Longdendale, he met with the common cockspur sliell (Turrittella terelra) in 

 considerable abundance. This place is about 450 feet above the level of the Irish 

 sea, in a deep gorge running from the Pennine chain. 



+ Man dialer Guardian, October, 1848. 



