OLDHAM: GEOLOGY OF MANIPUR AND NAGA HILLS. 11 



here spread out and occupy a broad tract of hilly country — a conclusion 

 that is supported by the fact of upper tertiary sandstones capping the 

 spurs on which Mapum and Poshing- are situated, and by the fact of 

 their coming in so far westwards as the Kopamedza range in the Angami 

 Naga country. 



21. I have already mentioned, paragraph 16, that the rocks capping 

 Koupru ridge and tne rid g" e to tlie west of tne Ti ki valley, appeared to 



hills north of Manipur. rest unc0 nformably on the slates below, and I find 

 that Major Godwin- Austen identified them as tertiaries, and as he dis- 

 covered marine bivalve fossils at Yemi and coaly matter in the sandstones 

 of Laisen, both high ridges to the east, I have accepted his identification 

 as almost certainly correct, and have coloured the map accordingly. 



22. In the Naga hills district the same rocks are found, here some- 



. what more indurated, forming the culminating 



Patkai. *3 



peaks of the Patkai range ; the sandstones, which, 

 where unweathered, might almost be called quartzites, and of which 

 some beds weather with a beautifully rose-coloured surface contain numer- 

 ous plant remains which, beyond the mere fact of their belono-ino- f or 

 the most part to dicotyledonous plants are unfortunately undeterminable. 

 Between Mao and Kohima the boundary runs in a straight line too 

 nearly north and south to be that of a natural escarpment of rocks 

 whose prevailing dip is south-west, or even in some places south-south- 

 west ; from Kohima the boundary trends to the westward passing under 

 Jotsoma, it curves round by Sachema and Karuphima whence it was not 

 followed to the north. 



23. To the east the upper tertiaries come in again within the boundary 



of British territory, the Kopamedza ranffe beino- 



Kopamedza. pi & 



composed of sandstones with intercalated slaty 



rocks which have a rolling dip trending away to the east. 



24. In only one position was I able to find any fossils other than 



plant remains, viz., in the gorge of the Diphupani, 



where a broad road has just been cut, for the 



most part out of solid rock, and in two places beds containing numer- 



( 227 ) 



