GEOLOGICAL DIVISIONS. 195 



From the list of authors given in Chapter I it may be gathered 

 how scanty is our geological knowledge of the 



Maps available. . ' <* ° 



region. On the other hand, the Survey of India 

 maps, most of which are on the scale of quarter-inch to one mile, and 

 some on the half-inch scale, are admirable in every respect, and I 

 regretted not being able to dispose of sufficient time to follow the 

 geological features into the detail which such a perfect delineation of 

 the topography would call for — a task which would be singularly 

 facilitated by the very excellence of such material. Not only was 

 the time at my disposal limited, but as my movements were not 

 always under my direct control, I was not able to turn it always to 

 the best advantage possible. Consequently, I have not ventured to 

 publish any of my work on the quarter-inch scale, except in the case 

 of the K6h-i-Sultan to the survey of which I devoted the better part 

 of one week (see map No. 2 ). The rest of the work has been 

 represented on a scale of sixteen miles to one inch. On this reduced 

 scale the sketchy nature of the survey becomes less apparent, and 

 the map may be regarded as fairly accurate in its main outlines 

 (see map No. 1). 



Section 2.— -Marine Strata. 

 (a) Volcanic Rocks, 



As it is impossible to discover any strict order of succession 

 amongst the marine stratified rocks, it will be more convenient to 

 classify them into volcanic and non-volcanic strata. 



These volcanic rocks are often very conspicuous amongst the bare 

 hill ranges owing to their dark colour, while the great height of the 

 ridges which they constitute compared with that of the softer and 

 more easily weathered shales and slates further increases the contrast. 

 They have already been noticed in other parts of Baluchistan and 

 were identified by Mr. Griesbach with the flyscb of Europe. 



They consist principally of tuffs freely interbedded with every 

 type of marine sediment and varying in coarseness from an agglom- 

 erate of huge boulders down to the finest ashes and porcellanites. 



c • ( 17 ) 



