OF ARKANSAS. , ^.23 



limestone is an impure, cherty member, about twenty-five feet thick. 

 This succession continues nearly to Salem, and the country is strewed 

 with the reddish and variegated chert, derived from these formations. 



Half a mile north of Salem, is an isolated, comical hill, called the 

 "Pilot Knob." A measurment made with the aneroid barometer, gave 

 its height four hundred and forty-five (445) feet above the town of Salem. 

 The summit is capped with a reddish, quartzose sandstone, and disinte- 

 grated fragments of the same are strewed on the sides of the "Knob;" 

 thus entirely concealing from view any other rocks which may exist at the 

 base. This is a conspicuous knob that may be seen from a distance of 

 many miles; hence it served, in early times, to direct the course of the 

 pioneers. 



Four miles west of Salem, there is a considerable bed of hydrated 

 brown oxide of iron, in connection with an impure siliceous ore, laying 

 exposed on a ridge, about one hundred feet above the general drainage 

 of the country. 



The geological position of this ore is probably the same as that which 

 has been before noted in Lawrence county. 



Both copper pyrites and galena, have been found in small quantities in 

 the magnesian limestones, in the southern and western part of the 

 county. 



Between Salem and Bennett's bayou, the substratum is a white earthy 

 limestone, resembling the " white rock " (b) of the Independence county 

 section, alternating with a greenish, marly shale, which weathers easily 

 and forms broad grassy valleys between the hills destitute of timber. 

 Bennett's bayou, along which is a rich agricultural district, cuts its way 

 principally through this stratum. 



In the western part of this county, on the North fork of White river, 

 there are seen, in the base of the hills, ninety feet of irregularly bedded, 

 impure, cherty limestone; the chert is very brittle, and has a tendency to 

 break into cubes. This is overlaid by one hundred and eighteen feet of 

 cherty limestone, alternating with a grayish-buff, siliceous rock. 



In the southern part of the county, on Piney creek, the saccharoidal 

 sandstone (c) of the Independence county section, forms the tops of the 

 ridges, and is covered with a heavy growth of yellow pine. 



Agriculture. 



The valleys of the numerous streams, watering this county, afford a 

 rich fertile soil, well adapted for cultivation; and that forming the small 

 grassy valleys, derived from the decomposition of the " white rock" ard 



