100 LAKE SUPERIOR. 



innumerable vertical fissures, of a line or two in width, and on an 

 average not more than an inch apart. These fissures were filled with 

 calc-spar. 



We had now got back to the line of our westward course, and 

 came this forenoon to the terraces spoken of Julj 15th. This re- 

 markable formation (see frontispiece,) consists of three main ter- 

 races with several subordinate ones, rising one above the other by 

 steep slopes. They occupy the whole bottom of the bay, (which 

 has here an apparent width of a mile or more,) having the slope and 

 curve of ordinary sand beaches, which indeed they evidently are. 

 The slopes and widths of each respectively are, according to the 

 Professor's measurements, as follows : — First the sand beach, rising 

 from the water 11° for about twenty yards, then for a short dis- 

 tance 7°. Above this a ridge of pebbles 15°, beyond which was a 

 belt of trees, and then a scanty growth of grass and a few low shrubs, 

 extending about two hundred and fifty paces, with an ascent of 6°. 

 From this an abrupt ascent of 20°, with a flat of fifty paces ; then an 

 ascent of 10° for a short distance, then sixty paces of 7°, and one 

 hundred and fifty paces of 5°. Then comes another steep ascent of 

 30° to 33° to a space fifty paces deep of 10° — 12° . Then another 

 ascent of 26° — 30°, succeeded by a succession of low, indistinct 

 terraces, and finally an ascent of 20° to the top, which is nearly 

 level for several hundred paces. The total height above the lake, 

 according to Mr. Logan,* is three hundred and thirty-one feet. It 

 will be seen that the whole presents a succession of acclivities in 

 some cases as steep as the laws of equilibrium allow, alternating with 

 slopes like the ordinary lake or sea beaches. 



The general' direction of these terraces is perfectly parallel to the 

 present beach, and at right angles with the sides of the bay, which 

 are high and rocky, and run in the same direction for some distance 

 inland. From the further side of the highest terrace there is a 

 uniform slope to a valley, apparently not much elevated above the 

 level of the lake, and filled by a marsh and a small pond. The ap- 

 pearance is that of a deep inlet dammed across by the lake. The 

 material is a coarse sand, with gravel, supporting a scanty covering of 



* Geol. Survey of Canada. [A report to the Gov. General, Montreal, 1847.] p. 31. 



