14^ GEOLOGY OF THE SON VALLEY, ETC. 



The small patch of ground about two miles S. by E, of Deora, 

 or on the left bank of the Son due north of 



Extent of area exhibit. 



ins Basal beds in this Ghusra, together with the narrow strip of land 



neighbourhood. 



commencing about a point Long. 8i° i6'*5 E., 

 Lat. 24 10' N., and running north-east as far as the confluence of the 

 Banas with the Son, is all the area that is occupied here north of the 

 Son by the beds of the basal stage. 



In the western parts of this area the top of the basal beds is 



formed by a limestone, which shows a good deal 



Limestone at top of . . 



Basal stage : its change- of variation even within a short distance, tor 

 instance, on the left bank of the Son, £ mile 

 S.-W. of Bakaili (or 5J miles S.-E. of Ramnagar) the rock is light 

 grey, non-crystalline, fairly pure and in beds of moderate thickness ; 

 while the same band of limestone presents at a point a little over 

 2 miles south-west of the last-named outcrop totally different charac- 

 ters — the rock being here mostly dark grey, crystalline, much veined 

 with calcite and with the bedding obliterated. Traced north-eastwards 

 the rock is highly siliceous by Mahadabur, but is purer again by 

 Kusma. The band narrows down considerably by Rimar, dying out 

 by Bela and replaced by a white earthy shale by Bartona. Eastwards 

 of this no limestone is traceable in this horizon, that is, in this little 

 area, except by Kanwari (one mile E. of Ludbad), where a calcareous 

 outcrop to the extent of a few square yards is visible. 



The rocks between this limestone which forms the top of the basal 

 stage here and the very bottom beds (conglo- 



General characters of & > J . 



the Basal beds near meratic) which form the range running N.E.- 

 S.W., south of Rimar and Bela, are not very well 

 exposed, but detailed observations show that in this neighbourhood 

 the limestone seems to pass down into a dark bluish earthy rock 

 ferruginous in places. Shaly sandstone with quartz and ferruginous 

 bands and quartzitic sandstone, light to dark grey and fine-grained to 

 coarsish, are next seen, while lower down ferruginous calcareous beds 

 with pale greenish shale passing down into a greenish argillaceous 

 shaly sandstone come in close above the quartzite which forms the 

 ( 142 ) 



