256 VREDENBURG: SKETCH OF BALUCHISTAN DESERT. 



beyond Mirjawa, so that the belt of parallel ranges still lies between 

 two depressions, that of the Mirjawa plain to the south-west and 

 of the great desert to the north-east. In its structure this 

 compound range affords a good instance of the manner in which 



Symmetrical structure the folded strata constituting the hilly region 

 of ranges. have been forced over the low-lying plain 



on either side : along either margin of the range the dip is inwards, 

 away from the plain, being north-east along the south-west 

 margin, south-west along the north-east margin. I have not travelled 

 right across the folded region at any point, but observations 

 made near Mirjawa and those made all around Saindak are 

 sufficient to give an idea of the main structural peculiarities. 



When describing the neighbourhood of Mukak (see ante, page 

 76), it was noticed that as the ranges gain in height, the amount 

 of disturbance also increases. North of Mirjawa the degree of dis- 

 turbance becomes still further marked, slaty cleavage is everywhere 

 present. The strata are extremely disturbed ; there are many local 

 variations both of strike and of dip ; the direction of dip varies from 

 north to north-west at angles of 55 to 70 . But there are many 

 minor disturbances, sharp folds and overfolds and small thrust-planes, 

 all indicating a movement of the rock masses in a south-westerly 

 direction towards the Mirjawa plain. The strike of the cleavage planes 

 is far more regular, about 35 N. of W. ; the dip of the cleavage planes 

 is inwards, away from the plain at very high angles of 65 and more, 

 sometimes quite vertical. The cleavage runs quite independently 

 of the bedding. 



Owing to such a degree of disturbance it is difficult to make 

 sure of the order of succession in the rocks : they include many of 

 the varieties usually found in the flysch series, limestone and calca- 

 reous sandstones full of volcanic material, shales and an extraordi- 

 nary abundance of very flaggy (and in the present instance slaty) 

 limestones and calcareous shales of the brightest hues, such as red, 

 yellow, mauve, white, pink, purple, green, There are several con- 

 spicuous outcrops of the columnar rock (PI. XI) which it was difficult 



1 78 ) 



