AND RECENT GRAVELS NEAR MANCHESTER. 459 



(No. 4). At the upper edge of these brick-yards we find 

 the following series, which, when I first visited it, I sup- 

 posed to represent a land-surface in the Drift, forming the 

 line of separation between the Lower Boulder- clay and the 

 Middle Sand. The section is as follows : — 



Fig. 4. Section at Heaton Mersey. 



a. Fine soft sand, 3 feet. 



b. Bed of peaty matter, and decaying stems and branches of birch, 4 inches. 



c. Dark, stiff, laminated clay, 6 feet. 



3. Middle Sand. 



4, Lower Boulder-clay, with pebbles. 



The bed of vegetable matter {b) consists of branches of 

 birch in a state of decomposition not much removed from 

 that of ordinary bog- wood. It is about 4 inches in thick- 

 ness, is overlain by a bed of fine sand («), which I supposed 

 at first to be the base of the middle sand and gravel of 

 which the hill is composed; and below are several feet 

 of a fine, laminated, brownish mud (c), without pebbles, 

 which I took to be the uppermost beds of the Lower Till. 

 These beds, however, contain no stones or pebbles, as is 

 usual with the Boulder Clay, and are more regularly lami- 

 nated than is generally the case with that formation. At 

 the same time, I had no reason to doubt that the whole 

 series belonged to the post-Pliocene group, and that we 

 had here a rare example of a true land- surface between two 

 members thereof. 



A few weeks after, however, I again visited the section 

 in company with Professor Bamsay, F.B.S., the Director 

 of the Geological Survey, who, on seeing the beds, gave it 



