River came to be so checked that a small portion of its superabundant water was detained in a lake. At present Wular Lake is about twelve miles long north and south by about six east and west, and, according to Stein, has a maximum depth of fifteen feet. It is surrounded on all sides by alluvial deposits, which have been built up in such a way as to leave at the base of the northern mountains the faint hollow in which the lake lies. The formation of the broad dam, so to speak, which holds back the lake, is due largely to the deposition of alluvial fans by the tributaries which come in from the north and south near the mouth of the Baramula gorge. In a moister epoch the forces of erosion would be less active upon the mountain slopes because of the thicker cover of vegetation ; the streams, though large, would not be very heavily loaded with detritus, and the tendency would be to cut away the fans and similar deposits which had previously been laid down, and to drain the lake. On the advent of a drier epoch, on the other hand, the forces of erosion would be more active upon the mountain slopes, and the average size of the fragments carried away would be greater because of the diminution in vegetation and in the number of roots which would hold the soil in place; the streams, especially the shorter, steeper tributaries, would be not only more heavily loaded, but also smaller; and the valley bottoms, with their comparatively gentle slopes, would become areas of. deposition. Where the swifter tributaries joined the slower main stream, they would tend to build up fans which the main stream, also diminished in volume and bearing a greater load, might not be able to remove. Thus the fans
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