38 ME. J. E. MARK ON THE TARNS 0E LAKELAND. [Feb. 1895, 



up with drift close to the lake, and partially filled with drift for 

 some distance down, but, except close to the lake, having its bottom 

 at a lower level than that of the floor of the present stream. The 

 nature of the lake, its present outlet, and the old valley (now nearly 

 dry) may be seen from the plan and sections (figs. 2-4). The first 

 section is drawn along the lower end of the lake, and the second 

 about 50 yards below the present exit. The presence of the 

 existing stream, on the side, as it were, of another valley, can 

 hardly be explained except on the supposition that the main drainage 

 was once down the old valley, and that when this was blocked up the 

 water took another route, and, 



owing to the existence of the Pig. 4. — Section across Smallwater 

 rocky barrier, has not been able Bed: 



to cut down to its former level, R „ 



and so the tarn has come into "^T^py^y^ V '■ sfrff 



existence. The old valley joins '^^^^-^ '■ _~^ffiff/ 



the present one about 250 yards ^^^^j^'/// / 



below the exit from the tarn, 

 and just below the above- 

 mentioned waterfall. t For Explanation, see p. 47.] 



III. Tarns between the Grasmere and Langdale Valleys. 



I have examined two tarns, Easedale and Codale, occurring on the 

 Grasmere, and one, Stickle, on the Langdale side of the watershed 

 between these two valleys. Of these, Easedale and Stickle Tarns 

 were considered by Prof. Hull to be moraine-dammed, 1 while 

 Clifton Ward 2 states that Easedale Tarn is, " when the depth is 

 considered, almost as good an example of a rock-basin as possible," 

 and that " Stickle and Angle Tarns are probably rock-basins of a 

 slight depth converted into tarns of a greater depth by moraines 

 at the lower end." 



Easedale Tarn has a depth of 71 feet, an exceptional depth for 

 the Lake District tarns so far as they have been sounded, and solid 

 rock occurs in the stream below the tarn very near the exit. I 

 found two possible moraine-blocked valleys, filled with drift to a 

 depth greater than the required 71 feet below the surface of the 

 tarn, one running in a south-easterly direction along a line of lode 

 to Blind Tarn Moss, the other starting along this lode, but curving at 

 right angles round a boss of rock which rises above the 1000-foot 

 contour-line, and joining the present beck 200 or 300 yards beneath 

 its exit from the tarn. Satisfied of the possibility of a buried 

 moraine-blocked valley, I proceeded towards Codale Tarn, but, 

 viewing Easedale from the heights, regretted that I had not 

 examined the ground north of the present exit, for the moraine 

 there is of great thickness, and I suspect that the actual valley will 



1 Edinburgh New Phil. Journ. ser. 2, vol. xi. (1860) p. 31. 



2 Quart. Journ. Geol. Soc. vol. xxxi. (1875) pp. 160, 162. 



