82 
Records of the Geological Survey of India. 
[vol. in. 
The denuding agencies acting strongly upon the varying consistencies of the rocks of 
this country have not only produced dominant features coinciding with the principal 
contortions and dislocations, hut in much more minute detail caused their stratification so 
to govern the forms of the ground that the minor contortions in many cases become plainly 
visible in the ornamental hill-shading upon the very excellent one-inch (to the mile) maps 
produced by the Topographical Survey. This is much most prominent in the soft tertiary 
rocks which form so much of the surrounding country stretching far into the outer Himalaya; 
and it- is partly a consequence of the steepness of the angles at which the strata are inclined 
in various directions. A wide belt of these tertiary rocks is known to border much of the 
Western Himalaya. Those which underlie them in the lulls between the Ganges and 
ltavee have also been ascertained and described by Mr. Medlicott in one of the Survey 
Memoirs. Westwards or north-westwards from the Ravee river this succession has not 
yet been clearly worked out, hut what, is known renders it probable that tho geology of 
this part of the hills will he found a continuation of that to the south-east. The very 
interesting Salt Range also exposes rocks older than this tertiary series which have 
not hitherto been identified with the infra-tertiary rocks of the Himalaya range. These 
lower rocks of the Salt Range, however, exhibit local changes, going from east to west, 
chiefly by the admission of new zones and by increase or diminution of thickness, and 
present a marked absence of all metamorphio strata. Hence it becomes a. fair inference 
that the formations inferior to those of the tertiary belt above alluded to, and the con¬ 
ditions which produced them, had very considerably altered within the large area indi¬ 
cated ; and some knowledge of the region wherein the transition commences would be 
very desirable. This region cannot lie yet pointed out, indeed it may very possibly be 
entirely concealed by the newer rocks; but Mount Til la is one of the nearest known 
places to the Himalaya range where the Jocks it xt beneath the tertiary belt appear, outside 
or within its Mints, as these may he assumed. These lower rocks appear only at the top 
and southern side of the lofty western part of the mountain, the extension of the ridge 
from this to beyond Ehotas being formed of the tertiary beds. 
The section afforded by the hill is as follows in descending or natural order:—* 
6. Tertiary [Sandstone and clays chiefly, with some) . , 
• 7 l conglomerate beds ... ... ) 
5. Nummulitie limestone 
^ f lied slmly and flaggy zone, with ) 
' | pseudomorphio crystals j 
3. Pseudo-limestone and compact sandstone zone 
2. Black-shaly zone 
^ Purple sandstone zone ... ... ^ 
1. ] Purple shale and ... ... ... £ Saline group 
(. Red saline marl ... ... ... J 
A vcrctge thickness. 
( Only part in section, 
{ about 6,080 feet. 
Maximum 30 „ 
( Very vari- ) - 
( able, about j ' 
150—200 
200 
( 250—300 
100 
( 20— 30 
- 120 
a knife-edge surmounting a precipice of several hundred feet in height, it was found necessary to proceed on 
all-fours. The wind came from the northward in such a way that much of the nearly two-miles-broad channel of 
the Bo on ha r rner to the south just below the mountain would have been thought sheltered. So far from this 
being the case, it was here only that the gale seemed to take effect, raising vast clouds of sand, completely 
obscuring the distant country, while on either side beyond the limits of the mountain where tho 
river course was not so sheltered the equally dry sand was not seen to rise at all- My guide observed, “ the winds 
urc born on Till and it certainly seemed as if its great mass had so influenced the temperature of the air that 
the storm was local, or its strength limited to the vicinity of the mountain: or it may have been an eddy behind the 
obstructing hill-mass.—A. B. W* 
* For the purpose of comparison with the distant succession 
general section is abstracted l'rorn Mr, Medlicott’s Memoir;— 
between the Ganges and Ravee, the following 
Sub-Himalayan Series. 
Upper. Sivalik 
Middle. Nahun 
Lower. Subathu 
Himalayan Series. 
Unmetamorpliic— 
Xrol . Ivrol Hill 
Infra-Krol ... ditto 
Blini. Blini River 
Infra-Blini ... Simla 
Metamorphic 
Conglomerates, sandstones, and clays. 
Lignite sandstones and clays. 
( Kasaoli, gray and purple sandstones. 
- Dugsinii, purple sandstones and red clays. 
(Subatliu, line silty clays, with limestone.— (Nummulitie ). 
Limestones. 
Carbonaceous shales or slates. 
Limestone and conglomerate. 
Slates. 
Crystalline and sub-crystalline rocks. 
