20 OLDHAM! GEOLOGY OF MANIPUR AND NAGA HILLS. 



42. Though I am not able to lay down the limit of the Tiki valley- 

 Limit of Tiki valley & mm S tne formation of the high-level deposits in 



during the formation of either valley, I am inclined to place it. as marked 

 the high-level terrace. *- 



on the map not far north of the low ground at 



Kaithamabi, for the high-level gravels there seem to be considerably 



higher, and more probably continuous with those oi the Ngordai valley, 



than those to the south. 



43. In the Ngordai valley there is, extending from almost its very 

 Deposits of the Ngor- head to w ^hin a few miles of the Barak river, an 



dai vallev - alluvial flat but little raised above the level of the 



stream, and above this fringing the valley, more especially on its west- 

 ern side, the remains of an old high-level deposit. About three miles 

 from the Barak the stream begins to cut into the alluvium, and at the 

 junction there is an alluvial flat some hundred feet or more below the 

 terrace, on which the Karong thanna is situated, and which seems to be 

 a continuation of the alluvium higher up the valley showing that, owing 

 to a lowering of its outlet in the Barak the Ngordai has within times, 

 geologically recent, begun to cut into its old deposits ; in its lower part 

 this erosive action has now ceased, and it is again forming an alluvial 

 plain at a lower level than its old one. 



44. The only other valley in which I saw any high-level gravels 

 High-level gravels of was that of the Thobal Turel, where there are 



terraces raised 80 or 90 feet above the central 

 plain of the valley, which is itself raised well out of reach of floods, being 

 at present cut into by the river. In this same valley I saw, what is pro- 

 bably the oldest of all the high-level grounds of this district, a small 

 patch on the very summit of the Hungdung spur, and over 2,000 feet 

 above the level of the river. 



45. The idea of the origin of the valley of Manipur common to all 



Alluvium of the Mani- previous observers, who have ventured to speculate 

 pur valley. Qn ^ g or jgj n ^ j s ^ a ^ ft [ s an \^ j a ^ e basin filled or 



dried up ; indeed, when seen from the summit of one of the surrounding 

 hills nothing could be more natural, the broad flat plain dotted with 

 ( 236 ) 



