374 TAYLOR POST-GLACIAL CHANGES IN ITALIAN AND SWISS LAKES 



lage is built on the larger remnant north of the stream. The business 

 and more compact residence portion is on the outer, gentler sloping part 

 of the old delta, while the church and many dwelling-houses are higher 

 up toward the head of the cone. The composition shown in some parts 

 of the bluff front and in banks of the ravine are like those described 

 above as being typical. A cross-section from the ravine lakeward shows 

 a typical delta form with detrital cone superimposed and indicates a 

 lake surface at time of construction 40 to 45 feet above the present water. 



Across the lake at Cannobio there is another good example of old 

 delta, but in a more eroded, fragmentary state. The torrent passes out 

 through a deep cut in the north side. The village is built on the old 

 delta surface, the same as at Maccagno. The general level in the busi- 

 ness part of the town is gently sloping toward the lake and 60 to 70 feet 

 above it. The outer edge of the gentler slope is 50 to 55 feet above the 

 lake. This is probably not far from the old lake level, which in this 

 case is not well shown. In the valley west of Cannobio, on the north 

 side of the stream, there is a heavy terrace with large boulders. The 

 body of the terrace is composed of till, and the stream now flows in a 

 ravine around its south side. Along the stream, but somewhat below 

 the main terrace, are fragments of narrow, secondary terraces cut in the 

 till. The main terrace appeared to belong to the time of the higher old 

 lake level. The secondary terraces were probably made while the stream 

 was cutting down to its present level. 



The projecting part of the delta of the Maggia between Ascona and 

 Locarno is low and broad and flat, and is composed of gravel and sand 

 and silt. This is not an old higher level delta, but has been made since 

 the lake came to its present level. The Maggia and its large tributary, 

 the Merlezzo, are mountain torrents, but for several miles in their lower 

 courses their rate of descent is moderate, so that they do not carry much 

 coarse detritus to the delta. The lake is shallower here than farther 

 south, and the present delta has been built out mainly in a horizontal 

 direction, so as to reach half way across the lake. The general situation 

 makes it evident that if the lake formerly stood, say, 50 or 60 feet higher 

 than now, the delta would have been of the same character — mainly of 

 the finer sediments. East of Ascona, where the delta laps around a pro- 

 jecting ridge, it has the appearance of a sharpl} r cut terrace 40 feet above 

 the lake, but is not in fact of that nature. A mile or more north of 

 Ascona and west of the main road a considerable flat area of fine deposits 

 suggests an old delta, but nothing more definite was seen. 



At Locarno and eastward there are many small torrent cones. The 

 village itself is built on a number of these, which blend together at their 

 sides, but they are much eroded and do not seem to show distinct evi- 

 dence of the place of the former lake surface. Where their slope is least 



