342 BOTANY AND PALEONTOLOGY 



Ironweed, tlie Wild Bergamot and some Greenbrier, vegetate upon the 

 tufa. In the basins which receive the water at the outlets of the springs, 

 three species of Conferva or green filaments are found attached to stones, 

 leaves, or pieces of decayed wood, or investing the woody pipes which 

 carry the water to the bath-houses. 



From the Hot Springs to the southwest of the county toward Magnet 

 Cove, the nature of the rocks is changed to a granitic formation, but the 

 vegetation preserves the same character as it had on the quartz, or on the 

 metam orphic sandstone. The banks of the creek which traverses Magnet 

 Cove have the Hornbeam and the Ironwood, with a few Oaks and trees of 

 the Buttonwood. Where they become flat and marshy, they are overgrown 

 by the Water and the Willow Oaks. The low hills and bottoms of the 

 cove are formed of a reddish ferruginous clay, a true iron ore which makes 

 a soil of greater fertility than would be supposed from its rocky barren 

 appearance. It produces, on an average, fifteen hundred pounds of cotton, 

 or fifty bushels of corn, or twenty bushels of wheat, per acre. This soil 

 covers only a small area. From the cove to Eockport, the country is 

 broken by steep, rocky hills, successively exposing the rocks which are 

 passed from the springs, but in a different order, viz., granite, quartz, and 

 then sandstone. Near Rockport, the tops of the sandstone ridges are cul- 

 tivated. But here we reach the alluvial formations of the Washita River, 

 sand, pebbles, &c, resembling drift, which have been carried by water to 

 a height of about two hundred feet above the actual bed of the river. 



GEOLOGICAL NATURE OF THE SOIL AND VEGETATION OF WASHITA RIVER, AND 

 OF CLARK AND DALLAS COUNTIES. 



This part of our exploration was not extended far, while the snow soon 

 forced us to abandon the field. Nevertheless, from the identity of geolo- 

 gical formations and of physical circumstances in the southern counties of 

 Arkansas, these remarks are probably applicable to the whole region south 

 and east of Hot Springs County, including the cretaceous, tertiary and 

 alluvial formations of the State. 



On account of the nature of the soil and of its natural vegetation, the 

 area occupied by these recent formations can be divided into two well 

 characterized sections. 1st. The upland, covered either by a sandy alluvial 

 ground or by red, sandy, sometimes clayey soil, resulting from the decom- 

 position of red tertiary shales, or of sandstone or clay beds of the same 

 formation. 2d. The deep alluvial soil of the bottom lands, or the low 

 swampy ground bordering the rivers and the creeks. 



In passing from the old formations of the coal epoch to the recent 

 tertiary and alluvial, the change in the vegetation is marked at once by 



