124 MALLET, VINDHYAN .SERIES. 



It would seem that the sandstone never attains a considerable thickness 

 save at or near the base of the series^ and it seems probable too that it 

 is altogether absent towards the top. This variability in the deposits is 

 also a point of similarity with the lower Vindhyans^ and with the 

 rocks more lately noticed by Mr. Blanford in the Grodavery area. 



As the most frequent bottom rock, the sandstones are seldom seen 

 in force except near the boundary, but they are nowhere so much de- 

 veloped as in the south-east, resting on the gneiss of the Jonk area 

 and of Sumbulpur, and forming ridges running northwards from that 

 area. If we wanted an appropriate name for the band, the Chanderpur 

 sandstone might be adopted; they have nowhere been' seen so x^eU 

 exposed or in so great force as in the ridges running south from the 

 Mahanuddi at Chanderpur. 



No constant position for the limestone can be indicated. It seems 

 thoroughly associated with the shales overlying the Chanderpur sand* 

 stone* * , , 



The position here distinctly assigned to the sandstone is the same 

 as is conjectured by Mr. Blanford for the Pranhita sandstone with 

 reference to the Pein or Pem shales, &c. In the Sone area a quartzite- 

 sandstone is the most general bottom rock of the lower Vindhyans. 



To the south of Nagpur, in the region about the confluence of the 



Weingunga (or Pranhita) and Wurda rivers, Mr. Blanford has recently 



mapped several large spreads of sandstone, to which the provisional name 



of Pranhita sandstone has been given. They are found resting on and 



faulted against the metamorphic series, and in juxtaposition with the Tal- 



cheer, Damuda, and Kampti beds, the junctions with which however seem 



to be all faulted with the exception of that south of Temburwai, which 



would appear to be a natural one, the Talcheer there resting on the older 



sandstones. The latter consist of white and purplish qiiartzite-sandstones, 



xvith which sometimes grits, in places felspathic, and conglomerates are 



associated. Ripple-marks are observable in parts. The strata usually 



( lU ) 



