7 ' 



GEOLOGY OF THE SON VALLEY, ETC. 



own observations extend principally over the northern portion of 

 map 481, and the southern portion of map 480. 



A\on<r the hilly region which extends south of the most northern 

 range of jaspers, there are two great runs of volcanic rocks. The 

 structure appears to be such as is diagrammatically represented in 



the following section : 



Fig. 5. 



1. Bed of the Son with the Vindhyans. 



2. Alluvial plain of the Son with the lowermost beds of the Bijawars : slates 

 interbedded with sandstones, limestones and lava-flows. 



3. The most northern range of the hematitic Agori jasper. 



4. The longitudinal valley of Sirwa and Piperwani largely occupied by lava- 

 flows and chlorite schists. 



5. The range containing Cheropahar hill, consisting largely of jasper, often 

 in a brecciated condition, with siliceous slates and slaty quartzites. 



6. The range containing Belawa peak consisting mainly of volcanic rocks. 



7. The broad undulating plain drained by the Gotun river ; it lies along the 

 central portion of the Bijawar syncline and the beds belong to the upper members 

 of that series. 



The most southern band of volcanic rocks, that which runs through 

 Belawa peak, has already been alluded to in connection with some 

 peculiar jaspers that it contains (see above, page 68). The next band 

 to the north of it has been examined with less detail ; but it contains 

 exactly the same varieties of rock and may be regarded with a fair 

 degree of probability as its repetition. North of the most northern 

 range of the Agori jaspers we get the slates underlying that horizon, 

 and here again we frequently meet with interbedded lavas. Of all 

 the rocks of this district the Bijawar jaspers are those that most 

 successfully resist denudation. If a wide band of volcanic rocks 



( 1* ) 



