ON THE GLACIATION OF EAST LOTHIAN SOUTH OF THE GARLETON HILLS. 21 



its retreat from the hill country, the latter shrank back into further recesses of the high- 

 level valleys and finally dwindled away to nothing. 



Very simple and straightforward evidence of local glaciation is afforded in the 

 neighbourhood of both Lammer Law and Soutra Hill. The former case is illustrated in 

 fig. 4. The Sting Bank Burn follows a deeply trenched valley running eastwards from 

 Lammer Law. A neatly cut high-level channel leads right across the ridge bounding 

 the valley on its northern side. It shows all the characteristics of a winding stream 

 course, with steep banks facing every curve. Its elevation above the Sting Bank Burn 

 is about 200 feet ; it is now quite dry, and as it cuts right through the ridge it has no 

 catchment area at its head whatever. It follows the bottom of a faintly marked 

 transverse col, which is lower than any other point for some distance along the ridge to 

 the east. To explain this high-level channel we must admit that the course of the Sting 

 Bank Burn was choked with ice streaming in from the tributaries to the south, but that 

 a small lake was permitted to form in the north-eastern angle of the valley which 

 drained across the col at its lowest point, and thus led to the cutting of a stream course in 

 what one would now style an impossible position. As the water which cut this channel 

 drained outwards from the hill country we have clear indication that local glaciers 

 remained in the high valleys after the great ice sheet had shrunk to a lower level. We 

 need only notice that the configuration of the land emphatically negatives any suspicion 

 that the great ice sheet could block the mouth of the Sting Bank Burn or the Hopes 

 Water into which the latter Hows, so as to form a lake whose outflow might have caused 

 this channel, for under such circumstances there could have been no possible escape for 

 a stream across the col, which would itself have been submerged. 



An exactly similar deserted high-level channel leading outwards from the hill 

 country is shown on the general map just west of Soutra Hill (see general map) ; 

 and while it confirms the deductions we have already drawn, it also enables us to 

 appreciate an interesting case of stream diversion which has occurred upon the other side 

 of the same hill. Originally, or rather in pre-glacial times, the Armet Water had its 

 source at Nine Cairn Edge, for the valley still continues naturally in that direction, but 

 the upper portion of the stream has now been diverted to the north and has given rise 

 to the Linn Dean Water. It seems clear on the ground that the local glacier, which 

 occupied the whole of the Armet valley, protruded a tongue northwards to the east of 

 Soutra Hill. The high-level gravels on either side of the Linn Dean Water represent in 

 a sense the morainic deposits of this tongue of ice, while the gorge of the stream was 

 cut by the waters issuing from the same. Certain minor diversions of the stream, more- 

 over, suggest that the glacier sometimes extended forward even into the water-worn 

 channel of the burn and forced it to cut a new course for itself a little to the one side or 

 the other. 



It is not impossible that the diversion of the Blinkbonny Burn (north of Sting Bank 

 Burn) should also be ascribed to a precisely similar interference on the part of a local 

 glacier. Originally this stream joined the Harelaw Burn to the east. Such examples 



