Abstract

The Valley of Massat, situated near the centre of the Pyrenees, opens to the west between two lofty mountains, which, at first approaching each other, spread out and diverge as they extend on the south-east towards the mountain-range of which they are the ramifications, so that in this direction the valley has no outlet. It thus forms an elongated basin, of a triangular form, the base of which extends along the side of one of the great spurs of the Pyrenees (see fig. 1), whilst the apex forms a narrow and winding gorge which affords the only outlet for the waters of the valley.

A short distance above the spot where the basin commences, namely on the western side, near the apex of the triangle, a high mountain of limestone rises up, which, advancing abruptly into the valley, forms an elevated promontory, against which the torrents or diluvial waters, which appear to have inundated this region at one or several remote periods, must have rushed. It stretches out almost at a right angle from the southern side of the basin; and, exactly where it extends furthest into the basin, its crest forms a mound or hillock, the summit of which is considerably more elevated than all the surrounding heights.