134 The Geology of the Cluden Basin. 



local, and were confined to the valleys only. Under a more 

 genial climate the valley glaciers, with intermittent pauses, began 

 their retreat, and in the act of dying entirely changed the whole 

 basins of Cluden and Xithsdale. In a field on Drumpark 

 estate, south-west of the Dunscore road and 100 yards above 

 Routen Bridge, the projecting knobs of hard greywacke are 

 nicely rounded and scratched. The stria.' on the rock are easily 

 seen to be pointing down the valley, thus indicating the direction 

 of the glacial flow in its last stage. This knob would act as a 

 stoss-seite or crag; while behind ir, in the direction of the falls, 

 we have the leeseite or tail filling up an old hollow. This 

 leeseite was partly excavated a few months ago to repair the 

 road, which had been damaged by flooding ; and now affords a 

 most interesting study. The material dumped by the ice consists 

 of boulder clay and gravel, alxiut 17 feet thick, rising to the 

 same level as the stoss-seite. The peculiar bedding of certain 

 parts of the till points to torrential streams under the ice flowing 

 at right angles to the direction of glacial flow. Higher up there 

 is a boulder pavement, indicating a temporary retreat and subse- 

 quent advance of the glacier. Prolvably this buried hollow may 

 represent an old river cliannel, now filled with the grjaund 

 moraine. 



At Drumjohn, on the other side of the river, we have 

 another ground moraine in the form of a pronounced ridge (or 

 drum). Its direction is not strictly parallel with the valley's 

 long axis, l)ut strikes it at a sharp angle in ihe form of a pro- 

 longed tail or leeseite. These drums are the characteristic of 

 the basin until Roughtree School is reached. We are now on 

 the verge of the 100 feet contour line, and confronted with the 

 change of phvsical features, as previously described. 



The geological map and memoir accompanying it describe 

 these grassv knolls remote from the stream as belonging to the 

 Kame gra\'el series, and in some manner attributed to glacial 

 action ; while those ridges near the ri\er are treated as frag- 

 ments of an old river terrace very much denuded. A typical 

 example of these is the high ground at Baltersan ; the promontory 

 containing the churchyard ; and the mound on which is placed 

 the covenanters' monument. To descril)e these rounded ridges 

 as fragments of a rWev terrace is not only erroneous and mis- 

 leading, but is also in such direct opposition to inTTisputable facts 



