DEPOSITS AND ELEVATION. 6 



of successive shores^ a second system of land-glaciation^ 

 at the same time that it bore down clay and sand and 

 boulders of its own making, carried down ofiF the new land 

 much of the older superficial drift, in its turn to be also 

 rearranged in the, so to speak, retreating ocean. 



The more ancient of these epochs has been elaborately 

 discussed by an acute observer in ' Frost and Fire ^ 

 (1865), an instructive and interesting attempt to group 

 and generalize glacial phenomena as a part of cosmical 

 history. 



The story of Great Orme's Head, as one of the lower 

 elevations of the district, and of its adjacent low-level lands, 

 falls within the latest of these, and passes beyond it into 

 the most modern of geological periods. Lately an attempt 

 has been made by the Rev. T. Gr. Bonney (Geol. Mag. iv., 

 1867) to trace ice- action over this hill and the neighbouring 

 range of the Little Orme's Head. This gentleman gives his 

 reasons for supposing that during the Glacial epoch the 

 Head was a low island with its undulating cap of ice of no 

 great thickness, — and, as to the Little Orme^s chain of 

 hills, observes that its undulating outlines are strongly sug- 

 gestive of glacial action, and says that the peculiar curves 

 of these ridges and their inner slopes can only be explained 

 by this cause. 



Mr. Binney, F.R.S., in a paper read to the Manchester 

 Geological Society (Trans, iii. 97, 1861), notes his observa- 

 tion, at a point below the Bath-house at Llandudno, of a 

 piece of brown limestone ^^^ situ, scored and polished probably 

 by ice. In the same paper Mr. Binney identified, below 

 a superficial series of slight depth and varying constituents, 

 a bed of brownish-coloured till, " containing angular, 

 rounded, and partly rounded pebbles,^^ appearing on both 

 coast-lines of the Llandudno isthmus. In this bed he 

 found fragments of Turritella terehra, and pointed out its 

 similarity with the till of the Blackpool cliffs, described by 



B 2 



