158 WYNNE: GEOLOGY OF KUTCH. [PART II. 



Section 6. — Portiost of the Central Plain near Bhooj and to the 



EAST AND west OF THAT PLACE. 



The extensive plain which separates the Charwar and Katrol range 

 from the broken chain near the Ruun^ a portion 

 of which has just been dealt with, is everywhere 

 underlaid by the upper Jurassic rocks. It is crossed by the courses 

 of several streams which rise among the southern hills and find their 

 way through breaks in the northern range out to the Runn. A few from 

 the eastern side of the plain, however, flow in that direction down to 

 the mangrove swamps at the head of the Gulf of Kutch. The surface 

 of the ground undulates, and is broken here and there by groups of 

 rugged hills or isolated peaks and low lines of escarpment formed by 

 the outcrops of beds, affording more resistance than usual to the erosive 

 agencies which continue to reduce the soft strata of the plain to sand. 



Over much of the latter this lies so thickly that a circuitous 

 journey is preferable to crossing such heavy tracts 

 where the winds arrange it into miniature knolls 

 and domes resembling those of a sea coast. 



Most of the hills are of the coarse white sandstones, but some are 



formed by intrusions of trap, and low long ridges 

 Quartz reefs. „ ,. , 



or reefs of quartz are very common, in some 



places clustered together or intersecting, but having no persistent simi- 

 larity of direction. These quartz reefs are prominently noticed in, and 

 some illustrations given with. Colonel Grant's paper abeady mentioned, 

 where they are described as ' Walls on the Runn,' 8fc. They have not 

 been observed, however, on the Runn itself, only on its edge, and 

 much more frequently scattered over the plain now under notice. 

 ( 158 ) 



