PART 2.] 
Ball: On the Origin of the Kimaiin Lakes. 
181 
The maximum depth, it will be seen, is given by Mr. Yule as 61| feet, so that 
I must have failed to hit off the deepest part. 
Of the smaller lakes enumerated above under class III, I have nothing to 
say at present. They have not yet been specially examined. Very possibly, there 
may he in connection with them various points of interest to bo yet discovered. 
Conclusions. —Reviewing the whole of the facts which are enumerated above 
in reference to each of the lakes, and considering the limited zone in which they 
occur—the probability that they are all the result of one general series of oiierations 
impresses itself as being an hypothesis of primary importance. If one of the lakes 
then exhibits indications which seem to connect it with one particular mode of 
origin, while others of the lakes do not show such or similar indications, it becomes 
all-important to submit the former to the severest scrutiny. In this way, I think, 
the appearances suggestive of a glacial origin, which are perhaps strongest in 
the case of Naini Tal, lose much of their force when wo find that other lakes exist 
of generally similar character, but in which the special indications are wanting. 
In the single character of the outfall barriers all the lakes agree; opinions may 
differ as to the origin of these barriers, whether they are remnants of mon-aines, 
or have been formed by landslips ; but it is almost certain^ that not one of them 
consists in any degree of rock in situ, and we therefore have not the positive aid 
of a rock basin to determine a conclusion. 
There is one point geologically which links the three larger lakes together, and 
that is the occni’rcnce of trap dykes in the vicinity of each. Row, I do not think 
it at all probable that the lakes are due to the original outburst of trap. Indeed, 
the above described fact in reference to Malwa Tal, where both the inflowing and 
outflowing streams cut through trap, renders such a view untenable. But it seems 
not improbable that, when the great upheaval and disturbance of the rocks of 
this area took place, the existence of comparatively rigid lines of rtap may have 
been largely instrumental in determining the form which the surface assumed, 
and that on their flanks the soft shales, &c., may hav^e been so much crushed 
and broken, as to yield more easily to the subsequent operations of denudation, 
thus affording an abundant supply of material for landslips, which ultimately 
served to close the valleys, and form the lakes.” Or even supposing the outburst 
of trap to have accompanied the upheaval and distiu’bance, its effect in deter¬ 
mining the subsequently established lines of denudation could not fail to make 
itself felt. 
This explanation, in part suggested by Mr. Medlicott’s observations in his 
well known jiaper on the Alps and Himalayas,® seems to me more in accordance 
with the known facts I'egarding the whole series of lakes, than any glacial theory 
can be. 
' Careful levelling can onl)' decide tliis point. 
^ It is possible that the basin of Naini Tal may be connected with some local faulting, the 
existence of which is implied by the sulphur spring at the outfall. That a fault occurs all along 
the centre of the valley is, however, scarcely probable, as, did one exist, it would show in the scarp 
of China, the beds forming which appear to be continuous across the head of the valley. 
’ Quar. Jour., Gcol. Soc,, February 1868. 
