BRITISH POSTGLACIAL &> RECENT DEPOSITS. 433 



about them is given by Dr. Hume, 1 and, as bis account is also 

 to some extent geological, it may be consulted with advantage 

 by those who are desirous of studying the matter in detail. A 

 more critical description of the deposits from a geological point 

 of view is furnished by Mr. C. de Eance, 2 who examined the 

 districts in question for the Geological Survey, and Mr. Mellard 

 Eeade 3 and others have also done much to increase our know- 

 ledge of the Postglacial history of West Lancashire and 

 Cheshire. 



The area occupied by the Postglacial and Eecent deposits 

 extends, as I have said, along the maritime regions of Cheshire 

 and Lancashire, and forms a low-lying plain that stretches 

 inland for several miles from the shore. Its inner margin is 

 pretty well denned by the 25-feet contour-line, but a large part 

 of its surface is below the level of the sea, which is kept out by 

 a long range of sand-hills that fringe the coast-line, and here 

 and there by artificial embankments. The deposits met with 

 throughout this broad belt of low ground vary considerably in 

 thickness, and seem upon the whole to reach their greatest 

 depth in the immediate vicinity of the coast-line, and what 

 appear to be old buried valleys. As they pass inland they 

 generally become thinner. Sometimes they do not exceed six, 

 ten, or a dozen feet in thickness, while in other places they 

 swell out to 80 feet. As might have been expected, the various 

 beds of the series seldom maintain a definite thickness for any 

 distance, but swell out and thin off irregularly, so that the 

 sections exposed in one district often differ considerably from 

 those that are seen in other places. And the numerous borings 



1 "Examination of the Changes in the Sea-coast of Lancashire and Cheshire." 

 Supplement to Ancient Meols. 



2 Quart. Journ. Geol. Soc., vol. xxvi. p. 657; Proc. Geol. Assoc., vol. iv. 

 No. 4. 



3 Geological Magazine, vol. ix. p. Ill ; Proc. Geol. Soc. Liverpool (1872), 

 vols. xiii. p. 36 ; xiv. p. 42. The reader will find in these and the works men- 

 tioned in the preceding notes, references to papers by Mr. H. Ecroyd Smith, who 

 has paid special attention to the antiquarian aspect of the question, and by Mr. 

 J. P. G. Smith, Mr. Cunningham, and others, who have published interesting 

 notices and sections showing the succession of the deposits. 



2f 



