42 ReconU oj the Geological Sim)eg of India. [voL. Xiil. 
suggested by Dr. Stoliczka), the borders of uhich were rendered brackish by 
the influx of fresh water. Subsequently to the deposition of these rocks, thei 
southern boj’dor of the western half of the zone was broken up by a large mass i 
of basaltic trap which followed the normal strike of the Himalayan rocks, as t 
being in all probability the line of least resistance. The Kailas range formed 
at a lower elevation the northern shore line of this gulf, while the southern 
shore line in all probability followed the northern boundary of the Palffiozoics of 
the Zanskar basin, and of the trap of the upper Indus. 
At the time of the deposition of the nummulitics, the upper Indus valley 
must have been a wide depression below the level of the sea, flanked on either 
side by land. Since the Eocene period this valley has been raised to an elevation 
of 10,500 feet above the sea-level below Leh, and it is in all probability owing 
to this elevation that the Tertiaries have obtained their present generally south¬ 
westerly dip. Tliis elevation of the Tertiaries (together, of coui’se, with the 
Surrounding rocks) to the north-west of the Zanskar river, mrxst have been so 
gradual and even as not to disturb the original relations of the rocks, and, 
judging from the southerly inclination of the Tertiaries, rvas probably of greater 
vertical extent on the northern than on the southern side of the Indus. To the 
south-east of the Zanskar river, where the Tertiaries attain the enormous eleva¬ 
tion of 21,000 feet (as in Tok (Kauri) peak, opposite Leh), the disturbance 
which they have undergone is considerably greater than to the w'est (where 
their elevation is less), and their southern boundary is often faulted. 
In the fonner area, however, those rocks do not seem to have undergone the 
puckerings and crumplings to which the PaliEOZoics have been subjected, the move 
ments causing which would seem to have taken place before the Eocene period. 
It seems not improbable, from the prevalence of the south-westerly dip in the 
Tertiaries, that their northern border Avas first elevated, and that to the cast of 
the Zanskar river, the higher conglomerates were deposited in a narroAV valley 
at the base of this newly elevated Tertiary land, Avhich was then rapidly under¬ 
going denudation. 
1 am thus led to the belief that tho great contortion which the pre-Tertiary 
rocks of Ladak have undergone took place in great part, at all ermnts, previously 
to the nummulitic period, and from the presence of Jurasso-Cretaceous rocks (and 
no neiver secondaries) in Zanskar (see below), that this contortion and denu¬ 
dation took place in the later Cretaceous period Avhon the country (except the 
Indus valley) first emerged from the sea, beneath which it has probably ever since 
been buried.^ From his observations in the Sub-Himalayan region, Mr. Medli- 
cott® came to the conclusion that the contortion of the older rocks there took 
place after the Nummulitic period, and he pointed out the importance of com¬ 
paring this relation with that in tho Central Himalaya, where a difierent condi¬ 
tion might preA'ail. 
> Against this view there is the apparent parallelism between tho Tertiaries and Carhonifei-ous 
on the Gia river, which would indicate, if rightly interpreted, that here the great part o 
disturbance was of post-Tertiary age. This is borne ont liy the greater amount of metamorplnsm 
and contortion which the Tertiaries to the .south-east of the Zanskar river have undergone in com- 
pavison with those to the north-west. 
2 See “Mainial of Geology, India/' p. 68i. 
