[S4i SUB-HIMALAYAN EOCKS OF N. W. INDIA. [CHAP. IV. 



The dip remains steady to the same direction, lowering to 50° at the 

 Gumber, the upper portion of the section being of alternating conglo- 

 merates, sands, and clays. The valley of the Gumber is cut along the 

 strike of these rocks. In the ridge, rising abruptly on the north of the 

 Gumber, we come again suddenly on the oldest type of rock, — hard 

 purple sandstones, and red clays. Throughout the ridge they are more 

 or less vertical, underlying now to one side, now to the other, but becom- 

 ing steady to a north-easterly underlie in the valley of the Gumrola, 

 where we again pass, without discernible demarcation, into the same 

 series of softish sandstones, clays, and conglomerates. The coarsest 

 varieties of the latter are in contact with the limestones and slates along 

 the main boundary, where they dip as usual at a high angle towards 

 the contact. 



There can scarcely be any question as to the existence of a great fault 



along the Gumber : this feature is traceable, with 

 The Gumber fault. . , . . T 



but little variation of character, past J ualamuki 



to the Ravee, near Bussowlee Ghat. In a south-easterly direction it is 

 very distinctly defined as far as the bifurcation of the river ; here the 

 feature in most direct continuation with it is a synclinal axis, along 

 which a ridge is soon developed, striking into the main boundary at the 

 village of Chandi, but orographically and structurally the lower Gum- 

 ber feature is represented in a parallel direction, slightly shifted 

 to the south-west, by the valleys of the Koaj and the Ballud. At 

 the low gap separating these two streams, the thick, coarse, soft sand- 

 stones of the outer ridge — the same rocks as noted on the ridge south of 

 the Gumber — underlie at a high angle to east-north-east, and thus seem 

 to pass beneath the thin, hard sandstones and red clays of the inner 

 ridge, the dip being about the same in both. The coarse sandstones 

 can be traced close up to the main boundary south of Khudi ; and thus 

 the well-defined belt of rocks north-east of the Gumber, at the Sutlej- 

 gradually dies out against the main lower Himalayan boundary. 



