191 ■•] STEVEXSOX— FORMATION OF COAL BEDS. 523 



in another connection, are equally in place here. That river, issuing 

 from the Malaspina glacier as a swift flood, lOO feet wide and 15 

 to 20 feet deep, has invaded a forest and surrounded the trees with 

 sands and gravel to a depth of many feet. That current, rapid 

 enough to carry a great load of very coarse material, was not strong 

 enough to uproot the trees and evidently it could not break off the 

 trunks until decay was well advanced. Russell's photograph shows 

 the conditions distinctly. 



Smyth^ has described conditions in the Adirondack mountains of 

 New York, which are of no little importance in this connection and 

 they will be utilized in the sequel, as the character of the region is 

 very like that imagined for some limnic basins in Europe. Many 

 small lakes exist in that region, varying from a few rods to three 

 or four miles in the longer diameter. They are of post-glacial origin 

 and, in many cases, are surrounded by high hills of metamorphic 

 rock, whence streams with rapid fall flow in comparatively narrow 

 valleys. Big Rock lake is typical. It is a mile and a half long, three 

 fourths of a mile wide and is fed by streams which carry much sedi- 

 ment and by their deposits are changing the outline of the lake. The 

 new area is a level marshv meadow, about a foot above the water, 

 covered with a heavy growth of grass and carrying some small bal- 

 sams and tamaracks. The lakes show every stage from pond to 

 meadow and one of them has been changed throughout into meadow, 

 through which its stream meanders on the way to Big Rock lake, one 

 mile away. After heavy rains, water flows over the meadows to a 

 depth of a foot or more, leaving a sediment of varying thickness; 

 but the torrential streams feeding the lake, though flowing through 

 gorges, whose steep walls are more or less densely timbered, rarely 

 bring down trees or other vegetation. 



Torrents carrying no debris do as little injury to vegetation as 

 to the rocks over which they flow. The writer has recognized this 

 many times in the Rocky and other mountain areas of the western 

 United States. Clear creek in Colorado, formed by the union of 

 streams from Gray, Torrey and other high peaks of the Front range, 



^ C. H. Smyth, "Lake Filling in the Adirondack Region," Amer. Geolo- 

 gist. Vol. XL, 1893, pp. 85-90. 



121 



