114 JVlALLETj VINDHYAN SEKIES. 



for trialj but they were declared to be " too silicious and too thin for any 

 practical purpose." In many of the quarries about Rotasgurh and Sas- 

 seram, the upper few feet of rock consist of a white or yellowish, soft, 

 porous friable material, which is employed as hwnee mnttee. The 

 bedding where it occurs is flaggy, and the lateral transition of the 

 same layer from the ordinary limestone into this material, may be 

 traced in places, so that the latter is clearly formed by the alteration of 

 the limestone. Analysis by Mr. Tween of two specimens (not however 

 taken from the same layer) gave- 



Limestone. 



Loss on ignition, after restoring C02 (chiefly 

 water and organic matter) ... ... 17*2 



Porous rock Porous rock 



equal in equal in 



weight to , bulk to 



limestone, limestone. 



3-2 1-28 . 



Iron and alumina S'O* 



5-6t 



2-24t 



Carbonate of lime 40-0 



•6 



-.24 



Carbonate of magnesia 13-2 



•2 



•08 



Insoluble in nitro-bydrocbloric acid (cbiefly 



sand and clay) ■■ 22-4 



90-8 



36-32 



100-8 100-4 40-16 

 showing that the lime and magnesia as well as the water and a portion 

 of the iron and alumina of the limestone have been removed from the 

 porous rock which consists almost entirely of that portion of the lime- 

 stone insoluble in nitro-hydrochloric acid. 



A variety of rock, often called chalk, is found in the neighbourhood, 

 which, amongst other uses, has been employed in the manufacture of soda 

 water, the analysis of which afforded Mr. Tween about 25 per cent.- of 

 insoluble matter, the remainder being chiefly carbonate of lime. 



In the Sone valley, where the lower Vindhyan limestones are princi- 

 pally developed, there is but little demand for lime owing to the wild cha- 

 racter of the country, but to the extreme west, at Moorwara, quarries have 

 been opened where the Jubbulpur railway crosses the outcrop. The Moor- 

 wara rock is the same as that at Rotasgurh. In Bundelkund the lower 

 Vindhyan limestones supply local requirements, but owing to the want 



* Chiefly alumina. t Chiefly iron. 



( 114 ) 



