Page:The Ancient Stone Implements (1897).djvu/705

Rh the Little Ouse and the Waveney, the one flowing westward, and the other eastward, take their rise in the same valley, and within a few hundred yards of each other, at Lopham Ford. With regard to the elevation of this spot above the sea-level, there has been some diversity of opinion. On the Greenough map, published by the Geological Society, it is erroneously stated at 15 feet; and Mr. Flower, in arguing in favour of his views, that the beds at Brandon are not connected with any river-action, assigns it a height of only 23 feet above high-water mark. That this also is erroneous can be readily shown, for Sir Joseph Prestwich has recorded the level of the Waveney at Moor Bridge, near Hoxne, ten miles below its source, as being 59 feet 9 inches above high-water mark at Yarmouth. Mr. Alger, of Diss, who has surveyed the district, informs me that the level at Lopham Ford is 75 feet 3 inches above high-water mark; and as by actual survey he found the fall, from the head of the Waveney to Hoxne Mill, to be upwards of 15 feet, there can be little doubt of this level being approximately correct. Still, the gravel beds at Brandon being upwards of 90 feet above high-water mark, there can be no doubt of their being at an elevation actually above the source of the present stream; and at first sight, this fact appears difficult of reconciliation with the view that they are due to fluviatile action. Without, however, calling to aid any possible oscillations in the level of the land, varying in amount at different parts of the course of the stream, an examination of the local geological conditions suffices to throw light on the causes, why the erosion of the land at the sources of the Little Ouse and Waveney has been abnormally great; so that not only have the streams excavated back the heads of their respective valleys until they have met, but their inclination at the upper part of their course, instead of being as usual in chalk countries at the rate of 12 to 18 feet in a mile, is only about 18 inches.

The general level of the country for some distance around Lopham Ford is at least 100 feet above it, and the Chalk and the superimposed beds are for the most part covered with a deposit of impervious Boulder Clay, through which the valleys of the Little Ouse and of the Waveney have been cut. But, at the time of the last emergence of this district of country from beneath the sea, this clay must have been continuous across the tract since