It is especially necessary to distinguish between three forms of alluvium, all of which have already occurred in Piti. These are, first, the fine clay; secondly, the platforms, such as I have described in the last paragraph; and thirdly, the enormous masses, which are without any definite limits, and do not seem referable to any present valley system.
We encamped at Pok, a large village nearly nine miles from Lari. Here we found again an extensive alluvial platform, covered with much cultivation; and on the mountain ravine above the village there was a considerable grove of young juniper-trees. A week or two before, I should have considered them as scattered trees; now they had quite the appearance of a forest, so bare had the country been since crossing Hangarang.
West of Pok, our journey of the 2nd of September was over the alluvial platform, which continued for two miles beyond the cultivation of the village, gradually contracting in width by the encroachment of successive spurs, which at last advanced close to the river. The road now ascended by a short steep path on the mountain-side, to a higher level. At the base of this ascent there were a great many angular masses of limestone, evidently transported from the valleys behind. These fragments were very numerous, and many of them of great size. They continued abundant during a great part of the day, but no limestone was seen _in situ_. I have not preserved any record of the exact position of these angular fragments with regard to the valleys behind, but I have little doubt that they will be found to be of glacial origin, such being certainly the case in many other similar instances. The limestone was very compact, of a blue or grey colour, and many of the fragments were almost full of coralline remains. I collected many fossiliferous specimens, which were afterwards despatched from Hanle to Simla by a messenger, on whom we thought we could rely, but they never reached their destination[10].
We encamped at Dankar, after travelling ten miles. This place is the principal village of the Piti valley, and is 13,000 feet above the level of the sea. The valley of the Piti is here very wide, and divided into numerous channels, which are separated by low gravelly islands, the whole width of the river being not less than half a mile. Here the alluvium is very highly developed, lying in patches on the face of the steep hills. The village of Dankar, though 1000 feet above the river, occupies both sides of a steep ridge entirely composed of alluvium. Nor is this its utmost limit; for several hundred feet above the houses, similar alluvial masses occur. These beds are not, however, continuous from these great elevations, down to the level of the river: they rest, on the contrary, on the ancient rocks, which are here very steep, and the clay may be seen in isolated projecting masses, capping the most prominent ridges[11].