LACUSTRINE CLAY.
November, 1847.
The lacustrine clay formation occurs in great quantity throughout the valley of Iskardo, and is nowhere seen in greater perfection than in the immediate neighbourhood of the town, where the cliffs facing the Indus, and those along the little lateral streams which descend from the south, exhibit an abundance of sections of these beds. The height of the cliffs is very variable; but it is seldom less than thirty feet, and to the east of the town is as much as a hundred feet. The clay formation varies much in appearance, being most commonly a very fine unctuous cream-coloured clay, stratified quite horizontally, but occasionally gritty and mixed with numerous particles of mica. Now and then thin beds of sand and of small waterworn pebbles alternate with the finer clays. In many places near the rock of Iskardo, the beds are very irregular, undulating a good deal, and at times exhibiting very remarkable flexures, as if the isolated rocky mass (which must have once been under water) had formed eddies in the lake, and prevented that regularity of deposition which is elsewhere so universal.
Fossils are very rare in these clays, but occurred in several different localities. Close to Iskardo I once found a very few small specimens of a Lymnæa and Planorbis, but after repeatedly searching carefully did not succeed in obtaining any more. I was more fortunate in two places east of Iskardo, where fresh-water shells are sufficiently common in one or two thin seams of very fine clay, mixed with a good deal of apparently vegetable matter. The great mass of the clay is, however, quite non-fossiliferous.
The surface of the clay formation round Iskardo is very undulating, and is often covered with masses of large boulders. Opposite two of the ravines which penetrate the mountains on the southern side of the valley, two very remarkable banks of boulders project forward into the valley. They consist of very large fragments of rock, angular or more or less rounded, piled on one another to a height of forty or fifty feet. They terminate abruptly, and are, I think, evidently moraines.
On the very top of the isolated rock, in the middle of the Iskardo plain, horizontal beds of coarse sandstone rest upon the hard clay-slate of which the rock is composed. This sandstone crumbles with great ease in the hand, the particles of which it is composed being very slightly coherent. These beds, in which I could find no traces of shells or of vegetable remains, are elevated at least 800 or 1000 feet above the level of the Indus. The sandstone seems to cap the whole hill, but is exposed only in a few places, being in a great measure covered by the loose drift or alluvium which has been deposited above it.
VEGETATION.
November, 1847.
The vegetation of Iskardo had so entirely disappeared, that I was able to form very little idea of its nature. A few shrubby species, and some withered fragments of autumn flowering plants, alone remained. On the whole, I was struck with the similarity of the few plants which I recognized with those of Nubra and Le. Artemisiæ and Chenopodiaceæ were still abundant. Hippophaë was the universal shrub along all the streamlets, and Lycium was common in sandy places; a berberry (the same already seen at Khapalu) was also frequent. The few novelties were Kashmir plants. Lycopsis arvensis, Prunella vulgaris, a thistle, a species of Sium, some gentians, and Ranunculus aquatilis, were the most Indian forms which I met with. From the mountains I procured specimens of a juniper (J. excelsa), and of the alpine birch of the Himalaya, which skirts the southern borders of the Tibetan region, without extending into the driest parts of that country.
CHAPTER VIII.
Leave Iskardo in the direction of Kashmir—First march through snow to Turgu—Lacustrine clay—it extends into narrow valleys beyond Nar—Gol—Junction of Indus and Shayuk—Parkuta—Tolti—Kartash—Extensive lacustrine deposits—Tarkata—Road turns up the Dras river—Ulding Thung—Fall of snow—Hardas—Karbu—Continued snow—Dras—Find pass in front shut by deep snow—Obliged to return to Iskardo—Rafts and rope-bridges on Indus—Elæagnus and Apricot apparently wild—Winter at Iskardo.
UPPER PART OF ISKARDO PLAIN.
December, 1847.