S33 Geological Formation of the Himalayan Mountains, [Apeil 



Budraj, formed of rounded grains of quartz, and tlierefore usually call- 

 ed sandstone. This varies in appearance, but is usually found at the 

 summits of the peaks, as on Budraj, Landour, and Surkunda, and 

 even on Deobun, in thin isolated strata above the limestone. In other 

 situations, it alternates ^vith the clay-slate, and then, as described by 

 Mr. Everest, " it becomes a distinct greywacke, consisting of a greyish 

 green base, with numerous angular fragments of clay-slate imbedded. 

 No such appearances could be observed in the slates which alternate 

 uith the Mussooree limestone ; and this circumstance, coupled with 

 that of super-position, seems to mark the quartz sandstone as the new- 

 est formation of the two." 



Section No. 2. — The claj^-slate met within the interior is usually 

 more uniform in appearance, especially in the line of the section, as on 

 Tuen, where, however, it is much waved and crossed by veins of quartz, 

 so on Acharanda and Jountgurh, and on to Bhok tibba. In the Khulan 

 valley, clay-slate is alone found, and a precipitous slip shows the whole 

 to be of uniform structure. At the head of the valley limestone is met 

 with in masses; the dip is very generally to the N. E. 



Micaceous and other Schists. — Mica slate occurs in ascending the 

 south-western face of the Bhok tibba, tbough clay-slate forms the mass 

 of the mountain, and is immediately succeeded by the mica slate and 

 gneiss series. The clay-slate sometimes passes insensibly into what 

 has been called quartz rock and even grauwacke in India, and in others 

 into mica slate, which is, in some instances, fine grained and dark co- 

 loured, so as hardly to be distinguished from clay-slate. Mr. Everest, 

 in proceeding from Mussooree, along the Ganges to its sources, men- 

 tions that quartz sandstone soon became the predominant rock, and 

 that the slate had nearly disappeared, being only found in the lowest 

 ground, opposite Ballahaut. The line of junction of the two was seen 

 only a few feet above the level of the river. Somewhat before this, 

 the slate had partly assumed the appearance of talc-slate, having a 

 faint glimmering lustre and a soapy feel. Beyond Ballahaut, he con- 

 tinued travelling near the line of junction of the two formations, the 

 slate gradually passing into a perfect talc-slate, and the quartzy sand- 

 stone becoming rather more crystalline than before. Perhaps the name 

 of quartz-rock might be more appropriate to it, though it still exhibited, 

 in some places, traces of round grains agglutinated together. About 

 Batwaree, the quartz sandstone ceases on the low ground, and the slate 

 contains a mixture of quartz and felspar, forming a talcose gneiss, with 

 hornblende occasionally intermixed. Traces of the quartzy sandstone 



