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of very fine silt, probably deposited in calm water, of which a 

 large amount of Nowgong consist, and which forms occasional 

 ridges in Jorhat, Sibsagar and Dibrugarh ; (4) a series of sandy 

 ridges running more or less across the line of the valley and 

 repeated again and again from Doom Dooma in the upper end of 

 the district down through Sibsagar (in small quantity), Jorhat, and 

 Golaghat down to the line of the Mikir Hills ; and (5) a. series of low 

 hills skirting the base of the Naga Hills proper throughout the 

 greater part of the Sibsagar district. These various ridges and kinds 

 of soil will be noticed, so far as I know them, in dealing with 

 the individual districts, which I will take in the order, slightly 

 modified, in which I visited them in November and December, 

 1900, and January of the present year. 



MANGALDAI DISTRICT. 



Mangaldai, the tea district lowest in the valley on the north bank 

 of the Brahmaputra, is found to consist of two absolutely distinct 

 sections, distinct in character of soil, in level, and in suitability fortea. 

 One of these is on a bank of sand near the hills ; the other is on land 

 only slightly raised above the rice level and much nearer the river. 



The former of these consists principally of grass land, ai'd 

 is composed of micaceous sand, light grey in colour, which, having 

 borne grass jungle annually burnt over for many years, usually 

 possesses a very rich surface soil, eminently suitable for tea. Like 

 most grass lands, the exceeding richness of the surface does not 

 extend to a great depth, but the following analysis of the soil to 15 

 inches deep of several gardens, show how very good the surface 

 soil of the virgin land must be. 



