On the morning of the 28th of September we resumed our journey towards Le. By crossing the Tunglung pass, we had again gained the eastern slope of the ridge dividing the waters of the Zanskar from those of the Indus. The Giah stream flows towards the latter river with a north-easterly course, and two marches of little more than seven miles each, brought us to the banks of the Indus at a village called Upshi. For the first mile after leaving Giah, the valley was somewhat open, with steep banks of alluvial conglomerate; it then contracted rather suddenly into a narrow ravine, with steep rocky walls, composed of highly inclined strata of conglomerate and sandstone. Owing to the diminished elevation, the vegetation was considerably more recognizable than it had been for the last week, and several shrubby plants were seen which had long been absent. Ephedra was common in the crevices of the rocks, and the Tibetan rose and a small shrubby Lonicera grew on the gravelly banks of the little stream.
REMARKABLE GORGE.
September, 1847.
At Miru, a considerable village where we encamped, the valley expanded into a little plain, filled as usual with alluvium, and covered with cultivation. A few poplar-trees occurred in the village. The ravine contracted immediately below this place, and was, if possible, more narrow and rocky than the day before, as the little stream had to be crossed not less than four or five times in as many miles, on small wooden bridges of rough planks. A very beautiful Labiate shrub, a species of Perowskia, with bright blue flowers, which I afterwards found very abundant in the Indus valley from 12,000 to 8000 feet, was here met with for the first time. Close to its junction with the Indus, the ravine expanded into an open plain, well covered with houses and enclosures, with scattered poplar and willow trees, as well as a few apricots, and traversed by canals of irrigation conducted from the little Giah rivulet. The Indus is here not more than forty feet wide, flowing swiftly over large boulders, and quite unfordable.
Throughout the whole course of this very remarkable gorge by which we descended from Giah, the rock continued to be conglomerate, alternating with strata of sandstone and of a very friable slate. The conglomerate was extremely hard, and generally of a dark brown colour. The matrix, which had often a semi-vitrified appearance, was not less hard than the enclosed stones, which were all rounded and very various in size and composition, jasper rock, granite, and quartz being all seen. The sandstone which accompanied the conglomerate varied much in colour, various shades of red, brown, and green being predominant. It was also extremely hard. These strata, which were highly inclined, often nearly vertical, were in general well marked, in consequence of the beds of hard sandstone and conglomerate being thrown out in relief by the more rapid decay of the soft slates with which they alternated. The dip was everywhere very variable, and several very distinct sections were displayed, where it was evident that the strata were curved and sinuated. The curves observed were convex below; the strike of the strata was nearly perpendicular to the general direction of the ravine, or from north-west to south-east.
INDUS VALLEY.
September, 1847.
From Upshi, our course lay down the Indus valley in a direction west of north. The width of the Indus, which was a rapid stream, varied from thirty or forty to a hundred feet. Platforms of alluvium, almost level-topped, and often attaining a thickness of a hundred feet, were interposed between the river and the mountains, which, still composed of highly inclined strata of conglomerate and its associated rocks, advanced in a succession of spurs towards the centre of the valley. These platforms were quite bare of vegetation, a few tufts of a prickly Echinops being the only plant worthy of note which I observed. No villages were passed till we reached Marsilang, at which we encamped after a journey of about ten miles. Here there was very extensive cultivation on the surface of the platform, on both sides of a deep ravine, cut in the alluvium by a considerable stream, which descended from the west. The plantations of willow and poplar were very luxuriant. The willows were planted in rows, and were frequently pollarded, their twigs being in great demand for baskets and other useful purposes in so treeless a country. When allowed to grow their full size, they spread much, and attain a length of upwards of thirty feet. The cultivated willows of Tibet are mostly European forms; Salix fragilis and S. alba are the most common. The poplars are of two sorts: one a spreading tree with large cordate leaves, which was first seen in Upper Kunawar, and is common in all the Tibetan villages, up to the highest limit of tree cultivation; it is quite identical with Populus balsamifera, which I cannot distinguish in the herbarium from P. laurifolia, of Ledebour. The other, which I had not before seen in Tibet, was a tall, erect, and slender tree, with much darker foliage and smaller leaves; it seems, so far as my specimens enable me to decide, to be the common black poplar (P. nigra) of Europe.
MARSILANG.
September, 1847.
At Marsilang the Indus is crossed by a good wooden bridge, thirty-four paces in length, which enables its inhabitants to communicate with the large villages and extensive cultivated tracts on the east bank of the river. As soon as we left the cultivated lands of Marsilang, on the morning of the 1st of October, we found ourselves again on a platform of alluvium; but after a few miles we reached another village, with extensive cultivation, and on the latter part of the day's journey passed through a succession of villages separated by gradually shorter intervals of unprofitable and barren land. These cultivated tracts were everywhere well irrigated; indeed, every spot, where irrigation was easy of execution, seemed to be under cultivation. Each village had its plantation of poplars and willows, not, however, so plentiful as at Marsilang. The grain had everywhere been cut and housed, the operations of harvest being seemingly quite at an end. The whole of this richly-cultivated district is called Chashut.
Our journey of the 2nd of October was for about six miles through an uninterrupted tract of cultivation, very little elevated above the level of the river, the alluvial platforms being here of inconsiderable thickness. The direction of the valley was also much more westerly, and the mountains on both sides had receded considerably from the river, leaving an open plain of five or six miles in width. Numerous irrigation channels intersected the fields, which gradually, as we proceeded, united one to another, till at last they all combined into one large and deep canal, by which the superfluous waters were conveyed to the Indus. Crossing this canal, we reached the river, which we crossed by a bridge twenty-five paces in length. A few houses, and a small patch of cultivation, lay on the right bank of the river, immediately beyond the bridge, but no extent of fertile country; low spurs of rocky hills descending from the north, close down upon the Indus. After crossing the bridge we turned up a wide and gravelly valley between two of these ridges, the course of which we followed, ascending very gradually among large boulders, strewed over the surface, for about three miles. We then turned abruptly to the left, through a narrow ravine in the low granitic hills by which the valley was on that side bounded. Emerging from this, we entered a quite similar and parallel valley, and obtained our first view of the town of Le, covering the top and slopes of a steep hill by which the valley was apparently terminated, about two miles beyond the point at which we entered it.
LE.
September, 1847.