24 GEOLOGICAL RECONNOISSANCE 



be satisfactorily seen. The subsoil is generally ferruginous. The surface 

 of the country is undulating; and the growth almost universally oak. 



The water of this region of Arkansas is remarkably pure, especially 

 that which comes through the gravel beds, containing less earthy salts than 

 I have found in any spring-w T aters in the western country. It lies, how- 

 ever, often deep, since it filters away through the porous beds of gravel 

 and sand to the depth, sometimes, of 90 feet, except where arrested by 

 local beds of interstratified impervious clays that lie, sometimes, at the 

 depth of 30 to 50 feet. 



In the neighborhood of Gainesville, f?ome lead ore has been picked up, 

 but there is very little probability that it is connected with any bodies of 

 this species of ore, accessible to the miner, since such ores rarely, if ever, 

 occur in the loose quaternary deposits, such as above described as pre- 

 vailing through this part of Greene county. It is much more probable 

 that they have either been brought there, and deposited, by the Indians at 

 some of their camping grounds, or been transported along with the gravel 

 from lead regions, lying to the north-west, either in Arkansas or Missouri. 

 A bed of lignite of quaternary date, crops out in the bed of the Beech 

 branch of Cache river, in Greene county, near the crossing of the Chalk 

 Bluff road, which runs on the Cache side of the Crowley ridge. It is partly 

 concealed under the water. It is overlaid by red and pink ferruginous 

 sand, and underlaid by clay. 



The succession and superposition, as far as they can be seen for vegeta- 

 tion and debris concealing the upper members of the quaternary beds, on 

 the Beech branch at this lignite locality, are as follows: 



Feet. 



Upper gravel bed 15 to 20 or 25 feet 20 



Red, tenacious, ferruginous clay 7 to 10 feet in thickness 10 



Second or lower gravel bed, 5 to 10 feet thick 6 



Pink and variegated sand, with some disseminated gravel, passing 



downwards into reddish white sand, overlying the lignite bed 25? 



Lignite bed partly concealed, 3 to 4 feet in thickness 3? 



Some of the sand is cemented, by the infiltration of ferruginous waters, 

 into a partially indurated rock. 



This lignite is of a blackish brown color. Part of it exhibits the woody 

 structure, and part has a more homogeneous earthy aspect, and lighter 

 blackish brown color. 



Both varieties are very similar in their character to the lignites of the 

 same age which occur in the quaternary deposits of the western part of 

 Ballard county, Kentucky. 



