ECONOMIC RESOURCES. 83 



In the extreme south of the area, and in the Brahmini and Bansloi 



Sandstones sections, and again in the north, a considerable 



variety of sandstones suited for building" purposes 



is exposed. It is by no means improbable that some of these might be 



found equal in quality to- the well-known sandstone which is quarried at 



Barakar. 



From the Talchir rocks flags of various colours and degrees of 

 TalcMr b ds hardness might be obtained. In some places a 



Talchir sandstone is quarried on a small scale by 

 the natives for manufacturing into curry-stones, plates, &c. 



Beyond the western boundary of the sedimentary rocks, gneiss and 



other metamorphic rocks, some of which might 

 Metamorphic rocks. . . s 



be used for building purposes, exist in considerable 



abundance and variety. The granitic gneiss which forms the islands near 



Colgong has been used in the construction of temples, &c. 



Laterite rock occurs on the tops of the hills, and for a considerable 



distance along their eastern flanks. In many 

 Laterite. . . 



places it is or sufficiently compact and dense a 



character to be employed as a building material. Evidence of its having 



been so used is afforded by certain old forts and temples which occur 



scattered over the area. 



ROAD-METAL. 



The basaltic trap is capable of affording an inexhaustible supply of 

 road material. There are, however, only a few localities where it occurs 

 sufficiently near to water-carriage to be economically available for the 

 requirements of Calcutta. 



These favorably situated localities are found on the north and 

 north-east limits of the hills. 



In the vicinity of Sahibganj, road metal has been quarried at several 

 different times and places, but from most of these localities the river is 

 from a mile and a half to two miles distant. The trap which occurs in 



( 237 ) 



