REVIEW GEOLOGY OF SOUTH-WEST LAXCASHIKE. 279 



lines of sand hills oi- dunes running along tlie coast. The solid geology 

 of the country is composed of Triassic strata, but these are hardly ever 

 visible, being covered over with beds of glacial drift, often as much as 

 150 feet in thickness. Of these the lowest deposit seen Mr. De Ranee calls 

 the Till. It is a dark leaden-coloured clay, occurring at elevations of 

 200 feet and upwards only. It contains angular blocks of local origin, but 

 no shells, and seems to have been formed by a sheet of land-ice. Upon 

 it rests the Lower Boulder Clay, of reddish-brown colour, with many 

 stones and boulders of lake-district rocks. It is finely exposed in the 

 chffs north of Blackpool. It is often stratified, and the stones, though 

 striated, are partly rounded. Hence it would seem to tell us of a period 

 of submergence when ice drifting from the north and east dropped its 

 stony cargo in a shallow sea. Shells are not uncommon. 



The Middle Drift Sand and Gravel marks a mild period, when 

 the glacial cold had decreased. It is sometimes as much as 70 feet thick, 

 but is often absent. The molluscan remains show a mingling of northern 

 and southern forms. It is commonly false bedded. 



The Upper Boulder Clay is sometimes 100 feet thick. It is of a dull 

 red tint, weathering on the surfaces or joints which may be exposed to 

 the air, to a bluish-white. Large boulders are rare, but glaciated stones and 

 shell fragments are common. Mr. De Ranee believes that it was 

 deposited under similar conditions to those of the Lower Boulder Clay, 

 viz., from ice-floes in a shallow sea. 



Thus the same triple division of the Drift is observable here as 

 obtains on the east coast of England. The two, however, were not 

 contemporaneous ; and it is a pity that the sama» names should have 

 been applied in each case to the different sub-divisions. Mr. S. V. Wood, 

 jun., has shown the great probability that the Lancashire Drift is of later 

 date than that of East Angha. Is it possible that the east and west 

 played a game of see-saw — the east coast first undergoing depression, 

 while land-ice scoiu-ed out Lancashire? The Geologists of the Midland 

 Counties must endeavour to aid in the solution of this problem, by 

 tracking the deposits as far inland as possible. 



In the latter part of his work Mr. De Ranee treats at length of the 

 Post-glacial deposits, especially peat ; of the economic uses of the various 

 deposits ; the water supply ; the deposition of shingle and sand forming 

 the dunes ; the action of tidal currents on the Lancashire coast ; and 

 various other interesting points. One valuable feature of the work is 

 that abstracts are given of almost all the papers that have been written 

 by previous authors on the subject. In an appendix (revised by Mr. 

 Ethendge) the occurrence of the various shells which have hitherto been 

 found in the glacial deposits of Lancashire is shown with great fulness. 

 On page 132 we note a very obvious misprint of " clay " for " crag." 

 Altogether, we evidently have in this Memoir the results of some years of 

 really tough work — of work which only a love for science could make 

 pleasant. Mr. De Ranee may be congratulated in that he has given us a 

 record of hard facts which wiU endui-e and serve as a work of reference 

 for many a year to come. 



W. J. H. 



