408 Expedition to the 



work its dissolution. It is of a yellowish red, or deep flesh 

 colour, which appears to be little altered by long exposure to 

 the air. Above the limits of phenogamous vegetation, it is 

 almost wholly naked — scarce a lichen or a moss is to be seen. 

 The line which marks the termination of the region of woody 

 plants upon the sides of the mountains, is that which, at the 

 time of our visit, f July 14,) separated the region of frost and 

 snow from that below. Above this line the soil is scanty, and, 

 where not buried under the snow, covered with a beautiful 

 carpet of herbaceous or sufFruticose plants. Another zone 

 might be distinguished above the preceding, and encircling 

 the summit of the mountain, in which scarce any phenoga- 

 mous plant is found, and but a few inconspicuous lichens. 

 The surface is covered with lar>;e and sphntery fragments of 

 granite, which seem to have been thrown down from above, 

 and owing to the compact and impenetrable nature of the 

 stone, appear as if rcctntly broken. No considerable al- 

 teration is apparent in the character of the rock, which is 

 similar at the base and at the summit of the cone of the 

 peak. A few fragments of perfectly transparent quartz, and 

 some pieces of bright green feldspar, and some detached 

 crystals of hornblend, are seen strewed about the surface. 



Sect. Ill, — Of the Ozark Mountains. 



Leaving the newest floetz trap rocks about the sources 

 of the Canadian, and returning eastward along the great 

 woodless plain between the Arkansa and Red rivers, we 

 find an extensive tract occupied exclusively by the red sand- 

 stone of the salt formation. The red and somewhat argil- 

 laceous soil, which results from its disintegration, is far more 

 fertile than that of the gravelly plains of tlie Platte, being 

 often covered with a luxuriant growth of grasses, and af- 

 fording pasturage to great numbers of herbivorous animals. 



About one hundred and fifty miles west from the conflu- 

 ence of the Arkansa and Canadian, this red sand-rock dis- 

 appears, being succeeded or perhaps overlaid, by an exten- 

 sive coal formation. The argillaceous sandstone of this for- 

 mation assumes variovis characters, at different points. The 

 Falls of the Canadian, particularly described in our narrative, 

 are occasioned by a small ridge of fine argillaceous sandstone 

 of a deep green colour, crossing the bed of the river ob- 

 liquely. The coal-[)eds in this regionare of great thickness, 

 and are apparently extensive and numerous. This formation 

 appears in a great measure unconnected with the coal strata 



