The Baluch Siwaliks afford us strange glimpses into a recent geological past, when the same gigantic mammals roamed along the foot of these wild hills as once inhabited the tangled forests below the Himalaya.
Between the Takht Mountain and the Siwaliks, the intervening belt of ridge and furrow has been greatly denuded by transverse drainage - a system of drainage which we now know to have existed before the formation of the hills, and to have continued to cut through them as they gradually rose above the plain level.
Beyond the Siwaliks, still looking eastwards, are the sand waves of the Indus plain; a yellow sea broken here and there with the shadow of village orchards and the sheen of cultivation, extending to the long black sinuous line which denotes the fringe of trees bordering the Indus.
The next succeeding deposit is a sandstone, often highly inclined, which rests unconformably upon the Nummulitic beds and resembles the Lower Siwaliks of the SubHimalaya (Pliocene) but which as yet has yielded no fossils of any kind.
Throughout the whole length of the chain, wherever the junction of the Siwaliks with the pre-Tertiary rocks has been seen, it is a great reversed fault.
The fault in fact was being formed during the deposition of the Siwalik beds, and as the beds were laid down, the Himalaya were pushed forward over them, the Siwaliks themselves being folded and upturned during the process.
Accordingly, in some places the Siwaliks now form a continuous and conformable series from base to summit, in other places the middle beds are absent and the upper beds of the series rest upon the upturned and denuded edges of the lower beds.
The Siwaliks are fluviatile and torrential deposits similar to those which are now being formed at the foot of the mountains, in the Indo-Gangetic plain; and their relations to the older rocks of the Himalaya proper were very similar to those which now exist between the deposits of the plain and the Siwaliks themselves.