[Sidenote: WATERWORN ROCKS. _December, 1847._]
The next day's march, from Turgu to Gol, round the great bend of the Indus, was entirely barren. On the western side of the curve several rocky spurs were crossed, but after the road turns to the south it runs generally on the surface of very elevated platforms of coarse alluvial debris, covered in many places with enormous boulders, partly derived, in all probability, from the fall of masses of rock from the cliffs above, but in more than one place so curiously arranged, at the apertures of lateral ravines, as to be, I think, almost certainly of glacial origin. Many of the large boulders which occurred in the alluvium were observed to be much waterworn, spherical cavities being worn out in them. Similar waterworn rocks were also seen _in situ_ at great heights above the river, in places to which no water has at present access, and where it is difficult to understand in what way the effect was produced. Behind the alluvial platforms, which are generally one or two hundred feet above the level of the river, the mountains rise precipitously, in cliffs of granite, which has now replaced the slate rocks of Iskardo.
[Sidenote: EXTENT OF LACUSTRINE CLAY. _December, 1847._]
At the point where the river changes its direction from north to south-west, the mountains on the southern bank advance quite to the river, and on the north side also they approach very near. It would therefore, at first sight, appear that the lake, in which the clay formation of Iskardo has been deposited, had here terminated to the eastward, no clay being seen in the narrow ravine above Nar, or near the river anywhere between Nar and Gol. I had at first no doubt that I had reached the eastern extremity of the lake; but some time after passing the most northerly point of the ravine I observed a patch of very fine cream-coloured clay, quite similar to the finest portions of the Iskardo formation, clinging in a remarkable position on the flank of a very steep rocky cliff, not less than 1000 or 1200 feet above the river. Several other patches came into sight soon after, all high up on the mountain-sides; one above the village of Golochu, and others at intervals all the way to the junction of the Indus and Shayuk. I cannot, therefore, doubt that the lake in which the clay beds of Kiris were deposited, was the same as that which occupied the Iskardo basin; nor does it seem easy to fix its exact boundaries. The great height of the patches of clay, in the narrow channel above Nar, show that the depth of the lake had been very considerable; and if we assume a depth of 1500 feet, which seems necessary, and at the same time admit the arrangement of the ancient rocks to have been the same as at present, we must either suppose some great barrier to have existed in the narrow passage below Khapalu, or must admit that the Khapalu lake was also continuous with that of Iskardo. I did not, however, observe any beds of fine clay higher up than Kuru, in the narrow part of the ravine of the Shayuk, which would warrant the drawing such a conclusion; although vast masses of alluvium certainly abound there, piled at great heights above the river. Is it possible that these may at one time have been continuous, and have blocked up the whole valley, and that the portions now seen capping ridges, whose origin is otherwise inexplicable, are the last remnants of a continuous mass which occupied the whole interspace? and if so, to what are we to ascribe the deposition of such an enormous mass of alluvium-like accumulation?