« ZurückWeiter »
a, Highly inclined rock overhanging the river, under which there is a narrow walk and wall at b. c, The parapet of the bridge. d, A tongue of land jutting into the river. e., The river Arve, which comes from behind the rock; at the foot of which is the tongue of land and the town of Cluse; the latter represented by three gable roofs of houses, and a wall round. f. Trees feathering the whole surface of the rocks on the right-hand side. #: Road
way from cluse to Bonneville.-N.B. The Valley of Maglanz is at right angles to t
valley in which the country between it and Bonneville is situated.
At Cluse (sg. 73.), the rocks are so curved that they overhang the river and road; and, near Cluse, the mountains are split from top to bottom, forming the Vale of Reposoir; and the same singularities are remarked at various places throughout the Valley of Maglanz. It had been my intention to draw up a paper on this valley, as offering some peculiarly interesting geological features; but the design was abandoned, from a pressure of more serious matters. The remarks of J. R. have reminded me, however, of it, and I shall add a few observations from my note book. As confirmatory of the views I have taken on the point, I may quote, at once, the words of MM. Barbe and Robert; who travelled through Lorraine and Switzerland in 1830, and published their observations in the Bulletin de la Société Géologique de France, 16mo, tom. i. p. 89.:—“La montagne schisteuse est singulièrement repliée, d'où se précipite la cascade d'Arpenaz, la suivante, formée d’ardoise, enfin une troisième située entre elles, au fond d'une petite gorge, forment parles directions de leurs couches, répresentées par des lignes droites, un véritable triangle placé obliquement sur une de ses pointes.” Nant d'Orli is the fall alluded to in the latter part of this observation; and the first grand variation from the horizontal position of the strata which occurs, is at Nant d'Orli. This is a beautiful cascade, which tumbles down the face of the rocks immediately behind the little village of Maglanz, from which it sometimes is called the Cascade of Maglanz. (sg. 74.) The height of the fall may be about 500 ft.: it is not of any great breadth, but the water Nant d'Orli. 1 2 3 4 5, The road to Nant d'Arpenaz falls with sufficient volume and force to work a saw-mill, built across the rivulet which carries it to the Arve. A vast mass of ruin is accumulated at the foot of the fall, the debris of the higher rocks, and on the summit of it there are growing pines of a great age.” We might almost suppose that these fragments were hurled down by the catastrophe which caused the fault by which the cascade was formed, and the size of the fragments affords an additional proof; so vast are many of them, that some children who were climbing them in search of wild strawberries, cherries, &c., whose voices were long heard, and directed us to their situation, were some time invisible to us, being hidden under the shadow of these mighty “screes,” as they would be called in Cumberland. The strata here are bent downwards on either side of the fall, so as to form a crevice in the front of the rocks which presents the more backward strata in the regular order, over which the water is projected. Fig. 74. will explain this. On a first inspection, it seems as if the strata had been bent downwards, continued horizontally in a lower position, and then bent upwards again to their former level. The continued
* [“What a noble tree is a mighty pine!, when growing in the situation it is intended for, on the mountain side; based on the solid rock, which its huge roots enfold, and, stretching deep, bind to the parent earth; its enormous trunk, unbent by storm or time, reaches towards heaven, “lythe by degrees and beautifully less;' its dependent limbs, laden with persistent verdure, shake icy winter proudly from their crest. Truly the pine is the mountain forest king, as the oak is that of the plain.”—Robert 1 }. Esq. in Gard. Mag., ix. 275.]
inclination of these strata would form a considerable o:
The thickness of the strata varies from 1 ft. to 20 ft., and in
some places the thicker strata are uppermost. This curious appearance in the strata is however only an
Bottom of the rocks at Nant d'Arpenaz, to show the buttress-like projections that enclose the lower part of the fall. The falls down lower than the road, which is crossed by the rivulet flowing from the falls into the Arve. a, The river Arve. Rise of strata to south. Dip of strata to north. Inclination of strata east to west.
indication of a far more singular and striking disarrangement. About half a league farther, the scene is graced by another most splendid fall, called Nant d'Arpenaz (fig. 75. and 76.), which comes down through a height of 800 ft. or 900 ft. in a brilliant descent. When the air is calm, and there has been a continuance of fine weather, the volume of water is by no means considerable; but after rain it is magnificent, and, if by chance a brisk wind should be blowing up or down the valley, the falling water is borne away along the surface of the rocks, till it becomes an invisible mist, when by its deposition it is again condensed and accumulated into another fall of equal beauty, so continuing its descent into its rocky basin below, whence it is carried, as the waters of Nant d'Orli are, to the river Arve. The beauty of this fall is not its only charm : for the extraordinary position of the strata near it demands equal observation. Approaching it from Nant d'Orli, upon the summit of the cliffs, which here appear sunk and shattered, the traveller is greeted with a view of what he at first believes to be an ancient castle, citadeled in the mountains. Seen, as the writer and his companion saw it, lit up by the bright rays of a setting sun, while the neighbouring rocks were in shade, it had a most beautiful and magical appearance: but it afterwards was found to be produced by a portion of the rock, which, by some cause, has been tossed over from its horizontal position, and piled up perpendicularly into the fanciful forms of turrets, towers, and bastions: there are even openings in these fragments in the exact position and shape of windows. (See fig. 77.) Immediately in conjunction with these, the subjacent and adjacent strata are bent upwards in their centre, at an angle of about 30°, and then continued regularly to the edge of the waterfall, which comes from a deep fissure through the mountain, and probably communicates with the feeders of Nant d'Orli, of which it may be only another branch: but of this it is almost impossible to be convinced by actual observation, on account of the steepness and distance of the mountains. On the right of the fall, instead of a horizontal position, the strata are deposited in concentric arches upon a diameter which forms the right cheek of the fissure. (See fog. 75.) By what extraordinary convulsion this can have been produced, there is no means of determining: for, although there are in this neighbourhood unequivocal marks of most extraordinary derangement, the extreme variety of forms which the strata assume baffles investigation. The concentric arches, above mentioned, are at first perfectly circular, but, as the middles of the strata are thicker than the extremities, they gradually become more and more eccentric, until, as they appear a few hundred paces farther up the river, they assume