376 TAYLOK — POST-GLACIAL CHANGES IN ITALIAN AND SWISS LAKES 



perhaps a little more. The old lake level in lake Como therefore rises 

 30 to 35 feet in 30 miles. 



Lake Garda 



The studies here, as on lake Como, were less detailed than on lake 

 Maggiore, but some of the evidences found are much more satisfactory. 

 The evidence from deltas on this lake is relatively poor, hut in its 

 southern expanded part there is a faint, but sharply cut wave-made 

 beach rising toward the north. 



The south end of lake Garda expands in bulbous form to a width of 

 10 miles, and it lies outside of the mountains in the lap of the great 

 moraine. I saw only the west shore of the expanded part. At Maderno 

 there is a well developed delta which shows evidence of the old lake 

 level at about 10 feet. There are faint evidences of wave action from 

 here southwest to Salo at about the same level. On rounding the point 

 east of Salo one obtains a good view of the shoreline from the steamer. 



It is here 7 or 8 feet above the lake, and its gradual descent south- 

 ward is easily noted. Its bench is 10 to 50 feet wide when cut in drift 

 slopes, and the cliff at its back is not over 5 or 6 feet high, and usually 

 lower. It is faint compared with beaches of our American Great Lakes 

 region, and is unlike our fainter beaches in that it is a sharply cut bench 

 wherever I saw it. Our fainter beaches are seldom cut, but generally take 

 the form of a low, more or less broken ridge of sand or fine gravel. 



The cut bench is well shown on a small island, Isola di San Biagio, 

 where the bench is cut all around, leaving a higher central part like the 

 crown of a hat. It is well formed also on the Sermione peninsula, but 

 on the rocks of the outer point it is scarcely distinguishable. It de- 

 with clines apparent regularity to within a foot or two of the water at 

 Desenzano, where it is not easily distinguished from the present beach. 



The west side of lake Garda, north of Maderno, is mostly precipitous 

 and the streams are small, affording poor opportunity for deltas. On 

 the east side at Ascenza and Malcesine there are faint marks of the old 

 lake level at 18 to 20 feet. At the north end of the lake, between Riva 

 and Arco, there is a tangle of torrent deltas built in by streams from 

 several directions. No definite evidence of the old lake level was ob- 

 served here, but assuming its plane to be produced from the south it 

 would be somewhere between 25 and 30 feet above the present lake, 

 agreeing well with the level of the delta deposits back of Riva. Thus 

 in 30 miles the old surface of lake Garda rises 25 or 30 feet. 



Lake Lugano • 



This lake is much smaller than the other three described. Its length 

 in a north and south direction is about 9 miles, but its outlet is nearly 

 midway of this distance. At the ends of its two south arms, at Capolago 



