102 DR. J. A. SMYTHE ON 



No connexion can, in general, be traced between these 

 « dry " valleys and faults. In one case, that of Fawdon Dene, 

 the direction of the dene does coincide with an important fault 

 bringing up Silurians against porphyrites. In other cases the 

 reverse holds; thus Selby's Cove (B7 in map 1) is cut directly 

 across a fault, and, in addition, a thick whin dyke. 



On the higher ground the dry valleys are often confused by 

 branched courses which isolate steep-sided rocky hillocks 

 (see Photograph 6) ; below the 500 feet contour they are 

 usually simple with, at most, a double loop at the intake. 

 Some are of great depth ; they are grouped irrespectively of 

 the present drainage system, and it may not be unnecessary 

 to mention, in view of recent utterances (Pres. Address Brit. 

 Assoc, 1 9 10), that they are often cut through drift and are 

 thus of later age than some of the glacial deposits. 



Washed deposits of three kinds are associated with these 

 valleys, viz., kaims and their attendant featureless deposits 

 of sands and gravels about the head of them, fragmental 

 river-terraces along the sides, and deltaic spreads at the foot. 

 The connexion with the kaims is two-fold, for the dry valleys 

 are best developed in those districts where kaims mostly 

 abound, and the maximum height of a given series of dry 

 valleys marks the limiting elevation of the kaims in the 

 immediate neighbourhood. 



The distribution of the dry valleys is clearly not haphazard. 

 All the ridges trending eastward to the coast between the 

 Tyne and the Aln are breached by them at heights varying 

 from 170 to 490 feet. Other important groups of them are 

 found on the watershed between the Font and the Coquet, 

 between the Spartley Burn and the Aln, and on the northern 

 and eastern flanks of the Cheviots. They seem to be 

 practically absent from the district drained by the North Tyne 

 and the Redewater, with the exception of the eastern water- 

 shed; a few, which have not been fully investigated, occur 

 along the line of the Roman Wall, and one very large one, 

 which carries the Tipalt Burn in its lower course, connects the 

 valley of the Irthing at Gilsland with that of the South Tyne. 



