Chap. II.] the Himalayan series. 71 



and connected with the disturbances of the sedimentary rocks. Over a 

 large area in the typical region of the Krol rocks I found no trace of trap 

 in these strata ; this is one of the many peculiarities for which this main 

 watershed region is remarkable, as already pointed out. It will be seen 

 in the next chapter that the nummulitic rocks, the Subathu group, 

 have only been preserved in this very same region, so that the absence of 

 trap in the Krol group here may account for its absence in the Subathu 

 beds also. There is another strong argument in favour of the same view. 

 I will show reason for conjecturing that the Krol group and the slates had 

 not undergone very extensive disturbance prior to the deposition of the 

 Subathu beds, and hence an additional probability . that the trappean 

 intrusions are also of more recent date. One of the few instances of 

 the occurrences of trap in the vicinity of the nummulitic area is seen 

 on the road side east of Saihutti, over the village of Tunsata ; a 

 vein of green-stone occurs there in the dark shaly slates underlying the 

 limestone. 



Trap rock is found most abundantly in those parts of the district which 

 In regions of disturb- are re gi° ns °f extensive disturbance. In the lime- 

 stone region of the Sutlej valley, between Komar- 

 sin and Dihur, there is a typical instance of this, as compared with the less 

 disturbed area of older slaty rocks to the south. The most continuous 

 exhibition of trappean action is along the base of the Dhaoladhar, and 

 stretching thence down to Suket ; in this region we find also vesicular 

 varieties of trap that I have not noticed elsewhere. As a rule, there is 

 very little variety in the composition or texture of the intrusive rock ; it 

 is a dense basic greenstone, more or less compact or sub-crystalline ; some- 

 times, in limestone rock, it is changed into a fine grained binary trap ; 

 good examples of this are to be seen in the Shali mountain. I have 

 nowhere noticed highly felspathic, or siliceous varieties. 



