SANDSTONE SEMES. 9 



Ttere can be no reasonable doubt of the metamorphics around 

 Nagpiir being an integral portion of the great series whicli occupies 

 the greater part of the country thence to the Bay of Bengal. The age 

 of the formations which have been altered into the gneiss, mica schist, 

 hornblend schist, quartzite, limestone, &c., which are its principal 

 constituent rocks, is quite unknown, but that they were all in their present 

 crystalline condition, before the deposition of the Vindhyans, is clear, 

 because the latter rest uneonformably upon them, and contain rolled 

 fragments derived from them, and the Vindhyans are of vastly greater 

 age than the very oldest of the sandstone formations found at !N'%pl!ir, 

 for the latter, as will be presently seen, contain rolled pieces of the 

 former. It cannot, therefore, be conceded that the plutonic rocks 

 contemporaneous with the alteration of the gneiss have affected the 

 sandstones found in the Nagpur area. 



2. — Sandstone Semes. 

 a. Tdlcldr group. — Rocks occur at two places near Nagpur, one of 

 which there can be very little hesitation in assigning to the Talchir 

 group, whilst the other probably belongs to it. The only important 

 exposure is that already referred to . as the red shale of Korhadi, 

 the type of Mr. Hislop's sub-division C of the sandstone series. 

 This occurs between Korhadi and Bokhara, about six miles north of 

 SitabaldJ. 



West of the Chhindwdra road, and north-east of the village of 



Bokhara, grey clays and yellow sandstones are 

 Bokhara. 



exposed in some ravines. They are, however, very 



ill seen, and all that can be said is that they are probably Talchirs. 



Gneiss appears to come in beneath them, but close to the road, yellowish 



sandstone is again seen at the head of a small stream which runs to 



the north-east. The recurrence of the sandstone is probably due to a 



fault. Following the little stream across the road, hard calcareous red 



b ( 303 ) 



