COUNTRY NORTH OF THE SON AND WEST, ETC. 141 



Chapter IX.— COUNTRY NORTH OF THE SON AND WEST 

 OF LONG. 82 30' E. (P. N. Datta.) 

 Crystalline rocks, — There is an area about Saria and Kubri ex- 

 tending eastwards as far as the mouth of the 



Crystalline area. 



Banas river, which between the basal beds of 

 the lower Vindhyans on the north and the Son on the south shows 

 crystalline rocks (gneiss) occupying the ground. It is upon this 

 crystalline floor that the lower Vindhyans were deposited here. 



The junction of the lower Vindhyans with the gneiss, which is 



well exposed at the point south-west of the 



Junction of the lower 



Vindhyans with the Rimar village where the Son cuts across the 



gneiss about Rimar. 



range formed by the basal quartzitic conglome- 

 ratic beds of the lower Vindhyans, is well traceable from near Rimar 

 as far as the mouth of the Banas river, with the exception of the 

 neighbourhood of Bakura, where a thick spread of alluvium occurs, 

 By Rimar the conglomerates are seen dipping N. W. by N. at 65 

 while the gneiss exhibits a foliation-dip of 78 to S. by E. The 

 gneiss as exposed here is a perfectly foliated rock. Associated with 

 it occur here also bands of hornblende schists. 



Here one mile S. W. of Kaithaha, near Saria, I found, on the bed 

 of the Son, a coarsely crystalline rock intruded, 



Intrusion in the gneiss. , ' 



evidently as a dyke, in the gneiss. This find is 

 of interest, inasmuch as the rock belongs to the olivine-norite group of 

 the dyke -rocks of South India and the lava-flows in the Cuddapahs. 

 Taken as the type of the group, it has been fully described by 

 Mr. T. H. Holland (Records, G. S. I,, Vol. XXX., pt. i, pp. 20, 21). 

 LOWER VINDHYANS. 

 I.-— Basal Stage. 1 

 This (the basal) stage is formed of the lowermost beds of 

 the lower Vindhyans, and includes Nos. 1 and 2 



Basal stage. 



of Mr. Mallet's sub-divisions of the lower 



Vindhyans. 



r Vindhyans, viz., into the Co 

 as first proposed by me in th< 

 , pt. 4, p. 145. 



( '4' ) 



1 The four-fold classification of the lower Vindhyans, viz., into the Conglomeratic(Basal), 

 Porcellanic, Kheinjoa and Rohtas stages, was first proposed by me in the Notes on Rewah in 

 1895. Rec, Geol. Surv. Ind., Vol. XXVIII., pt. 4, p. 145. 



