Note on a tank Section at Sealdah. 



155 



1864] 



a point of some interest with reference to the evidence of former 

 land surfaces which the section has disclosed. 

 Sealdahy Calcutta. 



Tine sand. 



20 ft. -\ Loam passing into blue clay. 



31 ft. 



46 ft 



1 It. Peat with tree stumps. 



1 ^ n, \ Clay with some sand and tree 

 10 ft. < i 



) stumps. 



"Lowest trees seen. 



15 ft. 1 



Blue chinch clay, with roots of 



trees. 



Black carbonaceous sand. 



Fig. 1. 



The section is illustrated in the accompanying wood cut, Fig. 1. 

 The upper 3 feet (more or less) consists of vegetable mould and made 

 earth, and rests on the irregular surface of bed a, the upper part of 

 which consists of fine loam, much like the soil of paddy fields, but 

 variable in different parts of the excavation. Thus in some places 

 it consists of fine sandy silt, minutely laminated, and crumbling 

 under the slightest pressure : elsewhere it is more argillaceous, and in 

 general it is very full of fragmentary vegetable remains, too imperfect 

 however to be recognised specifically, This bed becomes more argil- 

 laceous towards the lower part and near the base is a tolerably 

 tenacious clay. Its total thickness averages 17 feet, the bottom 

 being at 20 feet below the actual surface. 



Bed 6, is 1 foot in thickness, and consists of an impure peat, too 

 earthy to burn, when dry. In it several stumps of Sundri trees are 

 standing, the roots penetrating the bed immediately below. This 

 bed is continuous all round the tank, and appears to extend every- 



