80 GEOLOGICAL RECONNOISSANCE 



Specimens of soils were collected from this county, on the farm of Albert 

 Dugger, near the mouth of the Dry fork of Clear creek. The growth is 

 black-jack and hickory, with an undergrowth of sumach and hazel. This 

 soil will average about 40 bushels of corn, and 25 bushels of oats to the 



acre. 



On the divide between the Buflalo fork and the waters of the Dry fork of 

 Clear creek, the surface is strewed with a sharp chert gravel, overlying a 

 pinkish limestone, occupying probably the place of the marble rock of Ma- 

 rion and Carroll counties. Limestones of a similar character reappear in 

 the descent of the ridge, towards the waters of the Dry fork, associated with 

 a semi-oolitic variety of calciferous sand rock, perhaps of silurian date. 



I have, as yet, found no conclusive evidence to enable me to form a de- 

 cided opinion as to the age of the marble limestones of north-west Arkan- 

 sas ; but if they should, by subsequent observations, prove to be the repre- 

 sentative of the Onondaga limestone of the New York system, then it is 

 doubtful whether there are any rocks belonging to the iipper silurian divi- 

 sion in the western part of Searcy county, as the marble formation seems 

 to rest immediately on rocks of the lower silurian period. 



Some sandstone is interstratified with the limestones of the Dry fork of 

 Clear creek ; but these sandstones are older than the productal sandstone 

 of Burrowsville, in Van Buren county. 



The pink limestones are more earthy than the limestones occupying the 

 same geological horizon in the central portion of Van Buren county. 



