GEOLOGICAL NOTES ON ASSAM. 43 



I first came upon the rock conditions of the table-land in the 

 Eastern section of the extreme north-east corner of the area. A few 

 table-land. ^^i^^ g^^^^-l^ ^f Golaghtit, closG to the left hand 



of the DunseereCj and almost at the level of the alluvial valley, 

 the Namba stream has a fall of about ten feet over a low rib of gneiss. 

 "Within a few yards below the falls, and extending for some few score 

 yards down the stream, there is a low rock section — thin bedded 

 calcareous sandstones with partings of clay, and some compact 

 limestone. All are very flatly waved, but so slightly as to indicate 

 nothing positive. Having just come from the hills at no great distance 

 to the east, where, throughout 150 miles, I had seen an enormous 

 thickness of middle tertiary rocks greatly disturbed and forming lofty 

 ridges, I not unreasonably set these beds down as something much more 

 recent, possibly even sub-alluvial, though they differed greatly from the 

 older valley-deposits, as usually seen. The fossils in the limestone are 

 very obscure. Subsequent observation leaves scarcely any doubt with 

 me that these beds of the Namba are cretaceous. I did not go further up 

 the Dunseeree Valley, my route lay round the north flanks of the Meekir 

 Hills. In crossing the table-land to Asaloo by the usual track from 

 Nowgong, one first comes upon the overlying rocks at the falls of the 

 Kopili. There is here a section remarkably like that noticed on the 

 Namba. The most prominent rock at the falls is a rib of the very 

 same gneiss, it being very easily recognized by its strange ii-regularity 

 of texture, structure, and composition. The crystalline rock is here 

 nearly covered by beds of. fine hard sandstone. These stretch for some 

 little distance below the falls in unbroken horizontal strata ; and for some 

 way up stream there is a succession of little falls and rapids over the same 

 rocks ; some slight waving is apparent, but in strong sandstones, mth 

 an irregular bottom-rock close by, this might be altogether a local, or 

 even an original, feature. These actual bottom beds are here very fine 

 and pure sandstones; at the contact with the gneiss tlicy are much 



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