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Show 254 FALKLAND ISLANDS. March, 1834. · In many parts of the island, the bottoms o~ the valleys are covered in an extraordinary manner, by mynads of great angular fragments of the quartz rock. Thes~ have bee~ mentioned with surprise by every voyager smce the time of Pernety. The whole may be called "a stream of stones." The blocks vary in size, from that of a man's chest to ten or twenty times as large, and occasionally they altogether exceed such measures. Their edges show no signs of being waterworn, but are only a little blunted. They do not occ.ur thrown together in irregular piles, but are s~read out mt? lev~l sheets, or great streams. It is not possible to ascertam their thickness, but the water of small streamlets could be heard trickling through the stones many feet below the surface. The actual depth is probably much greater, because the crevices between the lower fragments must long ago have been filled up with sand, and the bed of the rivulet thus raised. The width of these beds varies from a few hundred feet to a mile ; but the peaty soil daily encroaches on the borders, and even forms islets wherever a few fragments happen to lie close together. In a valley south of Berkeley Sound, which some of our party called the "great valley of fragments," it was necessary to cross an uninterrupted band half a mile wide, by jumping from one pointed stone to another. So large were the fragments, that being overtaken by a shower of rain, I readily found good shelter beneath one of them. Their little inclination is the most remarkable circumstance in these " streams of stones." On the hill-sides I have seen them sloping at an angle of ten degrees with the horizon; but in some of the level, broad-bottomed valleys, the inclination is only just sufficient to be clearly perceived. On so rugged a surface there was no means of measuring the angle ; but to give a common illustration, I may say that the slope alone would not have checked the speed of an English mail-coach. In some places, a continuous stream of these fragments followed up the course of a valley, and even extended to the very crest of the hill. On these March, 1834. STREAMS OF STONES. 255 crests huge masses, exceeding in dimensions any small building, seemed to stand arrested in their headlong course : there, also, the curved strata of the . archways lay piled over each other, like the ruins of some vast and ancient cathedral. In endeavouring to describe these scenes of violence, one is tempted to pass from one simile to another. We may imagine, that streams of white lava had flowed from many parts of the mountains into the lower country, and that, when consolidated, they had been rent by some enormous convulsion into myriads of fragments. The expression, " streams of stones," which immediately occurred to every one, conveyed the same idea. These scenes are, on the spot, rendered more striking, by the contrast of the low, rounded forms of the neighbouring hills. I was much interested by finding on the highest peak of one range (about 700 feet above the sea) a great arched fragment, lying on its convex or upper surface. Must we believe that it was fairly pitched up in the air, and thus turned ? Or, with more probability, that there existed formerly a part of the same range more elevated than the point on whi~h this monument of a great convulsion of nature now lies. As the fragments in the valleys are neither rounded nor the crevices filled up with sand, we must infer that the period-of violence was subsequent to the land having been raised above the waters of the sea. In a transverse section within these valleys the bottom is nearly level, or rises but very little towards either side. Hence the fragments appear to have travelled from the head of the valley; but in reality it seems most probable, either that they have been hurled down from the nearest slopes, or that masses of rock were broken up in the position they formerly occupied; and that since, by a vibratory movement of overwhelming force,* the • "Nous n'avons pas ete moins saisis d'etonnement a Ia vue de l'innombrable quantite de pierres de toutes grandeurs, bouleversees les unes sur les autres, et cependant rangees, com me si elles avoient ete amoncelees negligemment Four remplir des ravins. On ne se lassoit pas d'admirer les effets prodigieux de Ia nature."-Perncty, p. 526. |