SI, 
Records of Ihe Geological Surrey of India. 
[VOL. III. 
being derived from the intervening earthy shale layers highly charged with iron-oxides. The 
latter become more numerous upwards, until the superior portion of the band is found to con¬ 
sist entirely of crimson and purple clay or shale. This group occupies a good deal of the 
ground from near Pind Sevicki by Ohoya Goojaron-ki, and above Nava; beyond which 
place it passes to the north side of the mountain, becomes thin, and thereafter is seen but 
fugitively hero and there as well as near the summit.* 
In some spots, particularly on the northern slopes of the mountain, vestiges of the 
nunnnulitie limestone group (5) so largely developed westward are apparent, resting either 
upon the red zone or, in its_ absence, upon the strong band beneath. It is seldom at all 
clearly seen; generally appearing as a thin white streak of debris, somewhat shifted and 
borne down the bill, and often overrun by other detritus ; but at one spot, where rather 
thicker than usual, it was found to consist mainly of the white, lumpy or yellowish variety 
usually occurring near the base of the group. Some gray, compact beds overlie this; 
and there are traces of a few dark shales in its lower part," as also of a peculiar bed of 
compact, variegated, red and white clay rook, frequently observed elsewhere at the base of 
this limestone group. The rocks on Mount Tilla contain but few of the numerous fossils 
of the group so far as could be seen. 
A small outlier of this limestone occurs below the road north-east of tlie houses on tho 
summit of the bill, having subsided with the other strata along a fault; and in the opposite 
direction, just beneath the precipice on the edge of which the highest bungalow is perched, 
remnants of the variegated clay-bed before mentioned indicate that the limestone bus 
barely been removed if, indeed, some of it in situ is not concealed by sub-aerial rain-wash. 
The inferior portion of the_Siy.il ik group ((!), which rests apparently with complete con¬ 
formity upon the uummulitic limestone, is mainly composed of strong, gray sandstones of 
rough texture and softer nature than any of those lower in the series. 'Thick beds of 
lumpy pseudo-conglomeratic shale also occur, and some beds of red, slialy or marly clay. 
Large fragments ot si lidded fossil wood are very numerous in some localities, particularly 
on top of the western end of the mountain. Over these clays comes a broad zone in which the 
sandstones alternate with thick beds of red clay at tho northern base of the hill for fully 
1,600 feet; and this zone is succeeded by another of probably much greater thickness, 
in which tho intercalated beds of clay are of a pale brown color, thero being little difference 
in the sandstones throughout. 
The less elevated continuation of the ridge from Mount Tilla proper on by Ehotas is 
formed almost entirely of what appear to be the lower portion of these Sivalik rocks, greatly 
crushed and contorted,_ generally inclined at steep angles to the north-west, but in some 
places more nearly horizontal; while contrary dips occur on the Jhelurn (or south-east) side 
of this extension of the ridge. 
To the eastward and east by north of Rhotas, the termination of the Tilla chain is 
fringed by low, rounded bills of loose conglomerate or pebble beds, mainly composed of 
smooth well-worn limestone and metamOrphic rock debris. These pebble beds also appear, 
generally in a disintegrated state, in the fine anticlinal, section of the Kalian gorge near 
Rhotas, and in one place were seen to rest uncoiit'ormably upon the Sivalik rocks; but 
owing to the extremely incoherent nature of the rock and its liability to Lave its debris 
re-arranged by atmospheric action, this cannot be asserted without considerable doubt; 
though to the east, along and near the Grand Trunk Road, the general arrangement of the 
conglomerate seemed discordant to the undulating dips of the Sivalik beds ; while the way 
in which the hills were overran with pebbles and boulders left small hope of satisfactory 
evidence being here obtained upon the point. 
Besides the fossil wood observed upon Mount Tilla, some fine mammalian remains were 
formerly procured from the Sivalik beds between that and Rhotas, and were determined by 
l)r. Falconer, as already mentioned. A set of beds containing numerous imperfect fragments 
of these bones runs along the summit of this lower portion of tho ridge close by the road 
from Rhotas to Tilla, near a place called Tluirbole. The bones were found in a frag¬ 
mentary state, imbedded in the matrix as well as lying loose upon the surface, but though 
some time was spent in the search, few useful specimens unfortunately could be obtained ; 
and, to procure such, a subsequent and special mission would lie probably required. 
* Tlie thinning ont of this red zone mov, perhaps, be partly due to pressure and slipping on the highly inclined 
slope of the beds at the north side of the hill, where the flaggy lower portion only is seen. 
