ON THE GLACIATION OF EAST LOTHIAN SOUTH OF THE GARLETON HILLS. 3 



dispersion. Later still the great ice sheet became further enfeebled and shrank away 

 back from the hills, merely leaving small local glaciers to linger on for a while in the 

 deeper recesses of the upland valleys. 



No doubt similar complications attended the growth of the great ice sheet, so that 

 one naturally feels some uncertainty in deciding the proper place in the glacial history 

 of the county of any particular event whose record has been preserved. Nevertheless, 

 the tale of the maximum stage of glaciation is not hard to decipher in its broad outlines, 

 and the approximate direction followed by the bottom currents of the great ice sheet 

 will be found indicated on the accompanying sketch map. We would, however, 

 recommend the reader to consult Sir Archibald Geikie's * glaciation map of Scotland, 



it* 



of 



f o 



r th 



oBass rock 



'BURNTISLAND 



\lNCHKElTH 



STABBS 

 HEAD 



Fig. 2. 



1. Coal-bearing divisions. 



2. Lower limestone group. 



3. Caleiferous sandstone series. 



4. Carboniferous volcanic rocks. 



5. Carboniferous dolerites. 



6. Old Red Sandstones. 



7. Old Red conglomerates. 



8. Old Red andesites, rhyolites, etc. 



9. Old Red granites, felsites, etc. 



10. Silurian and ordivician. 



11. Transported masses of limestone in 



neighbourhood of Kidlaw and Fala. 



since to understand the progress of events in East Lothian he must have a grasp of the 

 main features of the glaciation of the whole central valley. Thus in the west the main 

 ice cap of the Southern Uplands proved sufficiently powerful to ward off invasion from 

 the Highlands, and the two great ice-streams meeting at the base of the southern hills 

 in the plain of Ayrshire turned north-east and south-west to escape either way along the 

 central valley. But the Lammermuirs are low, and are bordered to the east by the 

 plain of the floor of the North Sea, so that before reaching them the Highland stream 

 was able to push its southern companion back upon itself and to creep up obliquely on 



* Scenery of Scotland, 1901, pi. iv. 



