ON THE GLACIATION OF EAST LOTHIAN SOUTH OF THE GARLETON HILLS. 9 



condition of affairs that has continued to this day is the anomalous drainage system 

 possessed by East Lothian and the adjoining coastal district of Berwickshire, the 

 existence of which has long been recognised. In fact, no better introduction to our 

 whole subject can be desired than the descriptions given, now more than forty years; 

 ago, by Sir Archibald Geikie* and Professor J. Young. t Besides giving a general 

 account of the anomalous drainage system, both these authors have singled out for 

 special notice examples which seem abnormal even in the strange company of their 

 fellows, and which, as we shall attempt to show later, owe their special peculiarities to 

 the processes of corrom formation. Sir Archibald's account deals with the Berwickshire 

 area, and runs as follows : — 



" Besides the ravines .... which are plainly the work of rivulets, there are certain 

 other narrow glens, defiles, or channels (for they vary not a little in size) in which there 

 are either no streams, or runnels so tiny and local that they cannot be imagined capable 

 by their own unassisted operations of hollowing out such marked excavations as those in 

 which they now flow. On the south side of St Helen's Church, for example, there is a 

 deep winding ravine, quite dry, running along the side of the declivity which here 

 descends gently to the edge of the sea cliff. It is open at both its eastern and western 

 extremity, thus running across the neck of a promontory. With the present configura- 

 tion of the land no stream could ever have flowed along this ravine. Other, but less 

 marked, examples may be seen along the sea front eastwards towards St Abb's Head. 

 Along with these features ought probably to be classed those valleys which go right 

 across the watershed in different parts of this district. Keference has already been made 

 to the valley traversed by the North British Railway J as affording a good illustration." 

 He then proceeds to give a description of the remarkable course followed by Edmonds 

 Dean Burn, which enters the railway pass " within a few yards of the flat watershed," the 

 latter being one of the corroms to which special attention will be directed later ; and he 

 concludes his account with the suggestion that some of the peculiarities of this drainage 

 system may be due to the modifying influence of direct glacial erosion. 



Professor Younu, however, in his description of the East Lothian examples, carefully 

 refrains from any expression of opinion as to the mode of origin of the valleys. 

 Having described the glacial grooving, he proceeds : — " In connection with these glacial 

 hollows fall to be considered certain valleys near the base of the hills, which 

 seem to belong to a system different from that of the present day. The flat green 

 valley § between Deuchrie Dod and Rammer Woods is bounded by steep declivities, 

 covered with low brushwood." After describing this abandoned waterway, the finest 

 in the district, he passes on to the Presmennan Loch channel, a little to the north, and 

 then draws special attention to the peculiarities of the Thurston and Aikengall drainage 

 systems, peculiarities which we now regard as a sequel to corrom formation. Returning 



* The Geology of East Berwickshire, 1863, pp. 51, 52. 

 t The Geology of East Lothian, 1866, pp. 63, 61. 



X Between Cockburnspath and Grant's House stations, eist of Dunbar. 

 § PL I. %. I. 

 TRANS. ROY. SOC. EDIN, VOL. XLVI. PART I. (NO. 1). 2 



