INTERGLACIAL EPOCHS. 



2 57 



in other parts of the quarry-section was intercalated with the 

 peat; while in some places the peat entirely disappeared, its 



Fig. 7. — Section of Glacial and Interglacial deposits, Hailes Quarry, near Edinburgh. 



place being occupied by sand and silt, abundantly charged with 

 vegetable ddbris. Sometimes the bed above the peat thickened 

 out to five or six feet, the lower portions containing many roots 

 and twigs which were wanting in the uppermost part of the 

 deposits. Immediately above these fine-grained deposits were 

 two or three feet of a coarse sandy clay containing many angular 

 and sub-angular stones and boulders (5), and this in turn was 

 covered by a mass of tumultuous till of variable thickness (6), 

 from a few feet up to several yards. To complete my account 

 of these interglacial beds, I give the following section taken from 

 another part of the same quarry (Fig. 8). This section shows a 

 thickness of 60 feet of glacial and interglacial deposits. Here, 

 as in the preceding section, we observe two masses of till, both 

 of them being of the same character. At its upper surface the 

 newer of the boulder-clays was somewhat discoloured, but only 

 for a foot or so. Below this depth it was a tough, dark blue, 

 amorphous till, crammed with sub-angular, blunted, striated, and 

 polished stones and boulders. The lower till (B 1 ) was underlaid 

 at one place (not shown in the illustration) with coarse shingle 

 and angular dAbris of sandstone and other rocks, the former 



s 



