J$J VRKDENEURG: SKETCH OF BALUCHISTAN DESERT. 



he somewhat in excess of true lavas. There remain to be noticed 



some smaller cones of very recent date consisting entirely of lava, all 



of which occur in the neighbourhood of K6h-i-Sulta*n ; the date of their 



eruption is far more recent than the period of activity of the K6h-i- 



Sultan and the Damodim. When undenuded they have a roughly 



hemispherical shape which is not a result of subsequent weathering, 



for their desintegration has only given rise to a limited talus beyond 



which no fragments occur. The lava was erupted in a viscous or 



pasty condition and solidified at high angles without flowing to any 



distance, giving rise to a type of hill which is well known by the 



Puy de Dome in Auvergne and the other trachytic bosses in its 



neighbourhood. K6h-i-Dalil is comparable in size to the Puy de 



Dome, perhaps even larger. Batil Koh (PI. XVI) 

 Batil Koh. . .. .. . ... , 



is of smaller dimensions; it rises on the 



southern talus of the K6h-i-Sulta*n and its stratigraphical relations to 



that talus constitute a proof of its very recent date. This southern 



talus is furrowed by innumerable ravines, and the Batil Koh rises 



upon the ridge between two of these valleys; it has not in the 



slightest way deflected the watercourses nor affected the general 



shape of the ridge as may be seen on the map and in the figure. 



Thus at the time of the eruption the talus presented practically the 



same topography as it does now, and the denudation of the K6h-i- 



Sultin had proceeded about as far as at the present day. Fragments 



of the boulders of lava forming the talus were observed caught up in 



the Batil Koh lava. The lava of Batil Koh is remarkable for the fact 



that it contains olivine, in perfectly clear transparent grains of a 



very pale straw-yellow. 



The K6h-i-Dalil, about fifteen miles east of Damodim, is of similar 



structure t0 Batil Koh - lt is of considerable 

 K6h-i-Dahl. . 



size forming a conspicuous object visible from 

 a great distance. The lava is a trachytic looking andesite with a 

 rudely columnar structure. Where slightly altered the rock has a 

 brick-red colour ; it is grey when fresh. It is very porous, the upper 

 surface of the lava being quite scoriaceous. Petrolooically it is 

 ( 104 ) 



