Lan 
THE Lower NITuH. 138 
Works, Heathhall, gives a buried channel 105 feet deep; No. 
2 bore, too feet. The works are built upon the 50 feet 
beach, and probably cover the bed of the Pliocene Nith, 
which was at least 55 feet below present sea level. 
RAISED BEACHES OF KIRKMAHOE. 
The depression of land in early glacial times to the 
100 feet level would bring the sea up to Dalswinton, and 
cause the formation there of an estuarine terrace, which was 
immediately covered with glacial moraines as the sea re- 
treated. During the formation of the 50 feet beach all pre- 
glacial channels were silted up near the shore line. This 
beach extends from Sandbed and Carzield past Kirkton and 
Carnsalloch to Heathhall. Not only was the old channel 
through Kirkmahoe deeply buried, but the Nith glaciers 
deposited large moraines at Carzield and Carnsalloch, and 
effectually barred the passage of the river. 
THE New NIrTH. 
The river had now to find for itself a new path to the 
sea, and its course was governed wholly by the movement 
of the glaciers or the arrangement of their deposits. The 
line of least resistance pointed south, but the glaciers of the 
Cluden valley coalesced at an angle with those of the Black- 
wood valley. The junction took place at Dalscone, and 
between the two sets of ridges the waters of the impounded 
Nith got through with difficulty. South of the burghs the 
Galloway ice travelling over the Maxwelltown plain deposited 
long drums of moraine debris from Corbelly to Castledykes. 
Again the river squeezed through the breach in the barrier 
and escaped. 
CARNSALLOCH FLOODS. 
The Dalscone barrier is a glacial drum of sand and 
gravel. Since the river began its new course it has trun- 
cated the ridge on the Holywood side, and cut down 15 to 
20 feet. While it was lowering its channel at Dalscone, it 
was compelled up stream to work in a lateral direction, 
hence the very large holms of Carnsalloch and Duncow. 
