PLATE LXXXIII. 



. THE EOVE LAKE PLATE, 1899. U.'S. GRANT. 



This area is divided in a pronounced manner between three types of topography. 

 In the south is the rough country prevailingly occupied by the " red rock." Here 

 are several hill ranges running nearly parallel with each other in an east and west 

 direction, the principal one, in the southern part of T. 64-1 W., having the distinct- 

 ive name of Misquah hills. This range contains the second highest known point in 

 the state, viz., 2,223 feet above the sea, determined by surveyor's level. Another 

 ridge is along the south side of Brule river, containing Brule mountain, on which is 

 located lake Abita, the highest recorded lake in the state, 2,048 feet above the sea. 

 A more southerly range runs along near the south limit of this plate, and is known, 

 in T. 63-1 E., as Pine mountain. This ridge reaches an elevation, in the vicinity of 

 Little Pine lake, of 2,000 feet. 



The second type is underlain by the gabbro. It occupies a triangular area in 

 the central part of the plate running to a point at the eastern margin. This is a 

 comparatively smooth region, with much rock exposure and numerous lakes elon- 

 gated east and west. This type is more marked in the area of the Gunflint Lake plate. 



The third type of topography is caused by the peculiar manner of succession of 

 the monoclines of the Animikie with their alternating sills of gabbro, or diabase. 

 The ridges, running east and west, are usually capped by the igneous rock, which is 

 sometimes 50 to 100 or 150 feet in thickness. Their lower parts are composed of 

 slates and quartzytes belonging in the central and upper parts of the Animikie. The 

 southern slopes of these ridges are gentle and descend frequently to lakes, below which 

 the igneous rock continues. The northern slopes are precipitous and sometimes ver- 

 tical, and descend across the faces of the sills which form the summits, and of the 

 underlying slates of the Animikie. This type of topography is likewise characterized 

 by east and west lakes, like that of the gabbro. There are some remarkable hills 

 belonging in this area. They are near the international boundary. 



The geological boundaries shown on this plate are not exact, but quite general. 

 The extent, as well as the nature and structural relations, of the red rock, is unknown. 

 This rock is known to be associated with diabases and surface lavas, as well as with 

 massive basic rocks of deeper-seated origin, and it is quite possible that these belong, 

 in part, to the Manitou epoch of the Keweenawan instead of the Cabotian, being 

 thus a westward extension of those represented on Plate LXXXI V about Green- 

 wood lake. N. H. w. 



