BH6T MAHALS OF KUMAUN. 153 



The remarkable feature of the carboniferous system is that it 

 seems to swell greatly in thickness as one advances towards the 

 south-east. The lower portion, the dark blue concretionary limestone 



(6) is in great force. It forms the lower slopes of the nameless 

 peak (20,344/) south-west of Girthi encamping ground, and I again 

 traversed it between Milam and the Uttardhura pass. This formation 

 is lithologically most characteristic, and though I have found no fossils 

 in it in the Johcir ground, its position between the silurian quartzites 

 (5) on one hand, and the overlying carboniferous red Crinoid limestone 



(7) into which it passes gradually, defines its age as devonian, or 

 lowest carboniferous. 



The red Crinoid limestone (7) with the white quartzite (8), both 

 nearly devoid of fossils, cap the great dome -shaped anticlinal of this 

 nameless peak, the sides of w r hich have been denuded down to the 

 lower carboniferous. More or less parallel with the permo-trias 

 boundary, strips of these two upper carboniferous divisions may be 

 traced from the Kurguthidar to the Uttardhura. 



In the profile pi. 10 the palaeozoic group is seen on the left 



side of the valley dipping gently forwards north-east, and falling 



under an angle of from 40 to 6o° below the trias on the right side of 



the Girthi valley. The latter has eroded through the entire group, 



and exposed the whole of the carboniferous rocks, and further down 



the stream, the silurian system also. On the right side of the valley 



rises a steep, generally inaccessible) cliff of trias and rhaetic which 



faces south-west and exposes the same section 

 Trias and rhaetic. 



as observed at Shal-Shal, and forms in fact a 



continuation of the same scarp (see pi. 10). The uppermost beds of 

 the cliff are formed by the dark earthy shales which I believe to repre- 

 sent a liassic horizon. This with the lithodendron limestones below 

 forms a high crest, eroded into wall and turret-shaped masses forming 

 a dip slope to north-east and presenting a precipitous scarp to south- 

 west. The entire mass of the trias-rhaetic group dips to north-east, 

 Flexures of the but are greatly crushed and contorted into several 



Kiangur. inverted folds, amongst which some local faulting 



may be observed. The most conspicuous flexure runs between 



( 153 ) 



