514 Kendall 8f Muff — Glacier Lakes in the Cheviots. 



in this area. Mr. Clough mentions ^ " dry, steep-sided little valleys 

 crossing over watersheds, vrhich do not appear to lie along lines of 

 weakness or the outcrops of soft beds. It is suggested that they 

 might have been formed by streams from glaciers." 



Some of the valleys observed by us run along the sides of hills or 

 occur as loops detaching portions of the walls of valleys, and the 

 general characters of similar valleys have been described by us 

 separately.^ Their mode of occurrence, and the relations to the 

 relief of the country as well as to the position occupied by the 

 ancient ice-sheets, show that they can be ascribed only to the over- 

 flow of water from lakelets held up by an ice-barrier. In the 

 country between Yeavering Bell and Ingram we found that each of 

 the spurs separating the valleys which radiate from Cheviot was cut 

 across by one or more sharp gorge-like channels, draining, with one 

 significant exception, to the south. The spur between Roddam Dean 

 and the Breamish River is cut, near Calder Farm, by a channel, 

 bounded on the east by the moraine, draining to the south, but 

 a higher portion of the same spur is traversed by a channel 

 draining in the opposite direction, i.e. to the north. 



The highest member of a series across any given spur is usually 

 just above the boundary of the drift, containing extraneous boulders. 

 At the outlets of the valleys there are in several cases deltas, 

 represented by masses of gravel. 



Conclusions. — The existence of the series of overflow channels 

 points clearly to the former presence of a chain of small lakes held 

 in the radial system of valleys of the Cheviots by a barrier of ice. 

 The ice-stream, by the boulders which it bore, maj' be inferred to 

 have swept round the end of the Cheviots out of the Tweed Valley. 

 The margin of the sheet at its maximum extension rose to about 

 1,000 feet along the arc from Yeavering Bell to Brands Hill, beyond 

 which it may have declined. Along the south-eastern slopes of the 

 Cheviots, another extraneous glacier swept in a north-east direction. 

 Where their confluence took place, or whether they were not in 

 succession rather than simultaneous, is not easy to decide, but 

 the Roddam Burn channel points very clearly to the preponderating 

 influence of the southern stream, while the Calder Farm overflow 

 lower down the same ridge shows by its southerly slope that the 

 northern ice later acquired the mastery. If the two glaciers were 

 confluent, then the overflowing waters of the lakes must have been 

 discharged eithor beneath the ice, as at present happens to the 

 overflow from a chain of ice-dammed lakes on the Malaspina glacier, 

 or over the top of the ice. 



An important and unexpected result of our brief examination has 

 been the discovery that while ' foreign ' ice was rising along the 

 flanks of the Cheviots to an altitude of 1,000 feet, not only were 

 the spurs free from any native ice-sheet, such as Cheviot or 



1 "The Geology of the Cheviot Hills " : Geol. Surv. Mem. 



^ P. F. Kendall, "On Extra -morainic Drainage in East Yorkshire": Brit. 

 Assoc. Eep., 1899. A. Jowett & H. B. Muff, " Preliminary Notes of the 

 Glaciation of the Bradford and Keighley District": ibid., 1900. 



