KAMET AND SP1TI. 21 7 



pi. 4) marks the upper boundary of the carboni- 



Upper boundary of 



carboniferous. . ferous system. J he strata forming it are there 



Permotrias. _.. , _ , A n «_ „^o u~i„ ±u 



seen to dip about 45 to 50 below the permo- 

 trias, forming a great synclinal fold between Muth and Tilling which 

 is splendidly exposed in the hill west of Khar (see pi. 5). 



It will therefore be seen that the Spiti carboniferous, so far from 

 being " not well exposed" * is well represented and even more fully 

 than in the sections eastwards. If I had only seen the sections in 

 Spiti, where the beds of the permo-trias seem to rest conformably on 

 the carboniferous, I would unhesitatingly have considered the small 

 thickness of Productus shales (9) at the base of the lower trias also as 

 carboniferous. But I have traced this contact from the frontier of 

 Nepal, from Byans through the entire range of the Central Himalayas 

 to Spiti, and found that whilst the Productus shales are never absent 

 from the base of the trias, forming with it as it were one great system 

 of beds, they overlap in succession the various horizons of the carboni- 

 ferous system in the different areas. For instance, the perrno-trias 

 rests in Dharma and Byans on an eroded surface of white quartzite ; in 

 other sections on red Crinoid limestone in the Niti area ; and here 

 in Spiti on a limestone with carboniferous fossils not seen in the 

 eastern sections. The inference therefore is that the permo-trias re- 

 presents one continuous sequence which overlaps 



Unconformity. ... 



the several horizons of the carboniferous, and 

 that the contact is unconformable. I can only again assert my convic- 

 tion, strengthened by many observations all pointing to the same 

 conclusions, that there are grounds for supposing that great physi- 

 cal changes have occurred in late carboniferous times, or at the 

 beginning of the permian era. I expressed this belief after my 

 first examination of the Niti sections in 1879 in the paper above 

 quoted. 



The pi, 4. illustrates the beautiful cliff west of the village of Muth 

 as viewed from the hills on the opposite side of the Pin river valley. 

 A series of small ravines have scooped out part of the hill-range at 



1 Records, XXI, pp. 151-3, 



( 217 ) 



