1 6 BLANFOTID : GEOLOGY OF NAGPUK. 



derived, and from the latter the name of this group of rocks has been 

 taken. 



As ah-eady mentioned, the exposure near SilewMa consists of a low 

 ridge striking about east-30°-south, about three 

 miles in length, and not more than 200 yards 

 broad ; the village of Silewada lying north of the centre, and on the 

 alluvium, with which all the country to the north and south is covered. 

 The beds dip south-30°-west at an average angle of 15°; neither 

 their top nor their base is seen, nor can their relations to the metamor- 

 phics, which appear at a considerable distance in both directions, be 

 ascertained. It is most probable that the sandstones are faulted on 

 both sides, the fault to the north continuing to Kelod in one direction, 

 and to Kamthi in the other ; but this is not certain, and can only be 

 inferred from the apparent straightness of the line of outcrop. 



Numerous quan-ies have been opened in the neighbourhood of 

 Silewada, upon at least four different beds, and 

 these afford opportunities for examining the sec- 

 tion to some extent, although the surface between the quarries is 

 much concealed by the debris taken from them. The following is 

 a combined section, made out partly from the rocks seen in the 

 quarries, partly from sm-face measurements, aided by information 

 obtained from the quarrymen, and, although only an approximation, it is 

 probably nearly correct as regards the succession of the rocks and their 

 average thickness : — 



Thickness 

 in feet. 



1. Compact coarse gritty felspathic sandstone, light brown or grey in colour, 



containing one or more thin hands of fine purplish argillaceous 

 sandstone, which is quanied in one place. This is the highest 

 bed seen, the thickness cannot he correctly determined. ... P 



2. Soft felspathic grit, very loose in texture, red, speckled with white, the 



top is not seen ; in one quarry there is exposed a thickness of . . . 15 



3. Yellow and red gritty sandstone, slightly micaceous, with gritty ferrugi- 



nous bands. ... ... ... ... ... 2 



( 310 ) 



