(32 GEOLOGICAL RECONNOISSANCE 



crevices in the rock, on the extreme northern confines of Arkansas, and 

 form this immense spring, which constitutes the head of the principal 

 branch of Spring river, watering the north-east, corner of Fulton county; 

 and then, entering Lawrence, it forms one of the main, streams of that 

 county; flowing, finally, into Black river, above Smithville. 



Since the death of the former proprietor, Mr. Mills, the ownership of 

 the spring, and the land around, has reverted to his heirs. 



For the sake of the interests of the country, we hope this water-privilege, 

 possessing so many natural advantages, will soon be improved in the 

 manner its intrinsic value justifies, and that it may fall into the hands of 

 enterprizing and practical manufacturers, who will give an impetus to 

 profitable and useful branches of manufacturing industry, suited to the 

 resources of the country, which soon attract around them an industrious, 

 progressive, and intelligent population. 



Extensive deposits of iron ore have been reported as occurring in 

 the vicinity of the Mammoth spring. I found some superficial specimens 

 of good ore in the north part of Fulton county, but have not seen any 

 extensive beds; those referred to by Mr. Mills, in a notice issued of his 

 property, before his death, are, probably, situated north of the state line, 

 on the western fork, in Missouri. The geological formation is such asjjto 

 justify the expectation that a detailed survey of Fulton county may dis- 

 close bodies of ore that might warrant the erection of furnaces. 



Descending south from the head of Main Spring river, I found the 

 country mostly constructed of low chert ridges, with prairie coves between 

 them; the timber being, chiefly, on the ridges, of a small growth of oak 

 and hickory. 



Two miles east of the Mammoth spring, a fine, white sandstone* crops 

 out on a slope on the Missouri side of the line. 



On Jaynes' creek, the same kind of country prevails. In the valley of 

 that stream, low benches of rugged, weathering magnesian limestone are 

 seen projecting from the slopes of the ridges, which are mostly strewed 

 with chert blocks, and gravel in the upper portions.' The highest of these 

 chert ridges are from 250 to 280 feet above the water courses, but the most 

 of them are considerably lower. 



* This is probably the equivalent of the sandstone represented on No. 4, which underlies the 

 marble limestones of Carroll county. 



