150 WYNNE : GEOLOGY OF KUTCH. [PART II. 



At a short distance south of this the stream crosses the large dyke 



before mentionedj as coinciding with the line of 

 Large dyke. 



the Kass scarp. The fault which accompanies it 



is well seen, its north wall being formed of gray shales, while it is in 



Fig. 10. — Fault and Trap Dyke on tte Nariery Nuddj, sub-recent conglomerate in nud distance and 

 Eoha hill beyond. ^ 



contact with strong sandstones on the south. Its width is here 93 feet, 

 and the alteration which it has produced in the neighboring rocks 

 strongly marked. This has extended into the shales for about 42 feet, 

 these showing a 28-foot band of deep black color crossing the beds 

 parallel to and at a distance of 14 feet from the dyke, the intervening 

 space having been from intensity of heat altered to a lighter colour. 

 The sandstones are also changed, being very hard for 20 feet from the 

 dyke, and within this distance the Belemnites which they contain, instead 

 of being composed, as usual, of dark coloured carbonate of lime (arragonite), 

 have become altered into a white opaque porcellaneous substance. Shales 

 succeed in such a position as to overlie these sandstones, and are inter- 

 sected by some of the same peculiar pyritous silieious sandstone veins as 

 occur in the glen to the east. The whole of these beds pass steadily 

 underneath the shales and sandstones of Eoha hill. 



A mass of sub-recent concrete, such as occurs in many of the glens of 

 this range, forms the upper part of the river banks 

 (in the middle of the sketch. Fig. 10 ), extending 



( 150 ) 



