ROCKY MOUNTAINS—WATERTON LAKE. 59 


appearance. With acid, the rock hardly efferveses in the cold, but on 
gentle heating is rapidly dissolved, leaving a comparatively small amount 
of residue, which, under the microscope, appears not to be of a detrital 
nature, but to have the form of minute concretions produced during the 
metamorphism of the rock, by the re-arrangement of the silica. There 
does not appear to be any unconformity between this limestone series and 
that of the underlying impure dolomites, of which it may be considered 
an upward extension. It indicates, however, a well-marked change in 
the character of the deposit; depending on the exclusion of the fine 
detrital matter forming so large a part of the previous beds,—a change 
brought about, perhaps, by the deepening of the sea. The limestone, 
where it crosses the lake folded into the anticlinal already mentioned, 
from its superior hardness, forms a projecting point from either 
side, and a transverse reef which almost divides the sheet of water 
into two. 
121. Series C. overlying the last, is well exposed in the bare sides of the 
mountains on both shores of the northern end of Waterton Lake. On the 
east side, a great portion of the western front of Mt. Wilson is composed 
of it, while to the west, a mountain rising about 4,000 feet above the 
lake, is almost entirely formed of these beds, which have there been 
subjected to violent flexure. (Sects. 6 & 8). Asa whole, this division 
of the section may be described as consisting of hard quartzites, sand- 
stones, slates and shales; and its most remarkable feature is the rapid 
alternation of beds differing in colour and texture. Various shades of 
green, purplish-brown, red, and white, are the most prevalent tints. 
122. In the almost vertical western side of Mt. Wilson, about two 
thousand feet of these beds is seen. They lie directly on the last 
mentioned white limestone, and if any unconformity exists it was not 
observed. Here two pretty thick bands of magnesian grit appear among 
the other rocks of the series, and may be distinctly traced along the 
mountain side for some distance. At one end of the section a considerable 
thickness of red beds occurs, as the highest in Series C., and in some 
places these are seen to underlie directly the limestone of Series D., next 
in order, while in others they are wanting, and D. rests on the lower 
green slates and sandstones, showing a well marked unconformity. 
(Sect. 6.) The mountain on the western side of the valley of the lake, 
shows but a single band of the magnesian sandstone, which is very 
irregular in its thickness. The red beds are only clearly seen in a few 
places, and faults may exist which complicate the structure more than is 
