38 GEOLOGICAL RECONNOISSANCE 



compact and cellular chert; the latter partaking of the character of buhr- 

 stone. This chert is, in all probability, of subcarboniferous date. The 

 surface being much encumbered with blocks and protruding masses of 

 these siliceous rocks, the soil is necessarily thin, and supports a growth 

 almost exclusively of small oak. Nevertheless, the soil is capable of pro- 

 ducing much better than the forbidding nature of the rocky surface would 

 lead one to suppose. 



The descent from these chert ridges to the " Big Spring," is about 260 

 feet. Here, a noble volume of the clearest water silently rises from some 

 cavernous passage at the foot of an amphitheatre of hills of cherty, sili- 

 ceous limestones, sufficient in quantity to supply the wants of a small grist- 

 mill. Like all those streams having a subterranean origin, it never freezes 

 in winter. This Big spring is quite a noted locality in Independence 

 county. The water-power it affords, and the improvement in the soil of 

 the country, watered by its branches, has attracted agriculturists, who 

 have opened several good farms three miles south of the Big spring; but 

 north-east, towards the Rocky bayou, the country is mostly rocky oak-bar- 

 rens, with a broken surface, where few settlers have located. 



The cavernous or barren limestone group, capped with chert, prevails 

 to Lafferty creek, where it is underlaid in many places by a very white 

 sandstone, some of which is sufficiently pure to make glass. 



The dip is irregular; at one place the inclination was observed to be 10 



deg. S. W. 



I examined a salt-petre cave situated from half to three quarters of a 

 mile north-west from Tosches' farm, and about 250 to 300 feet up in a 

 ridge of subcarboniferous limestone. This cave is known as the " Salt- 

 petre cave," and is owned by Col. John Miller. 



It has passages from 200 to 300 yards long, and 8 to 10 feet wide. The 

 sacks containing the earth from this cave have, unfortunately, never come 

 to hand, so that we cannot report upon the per centage of salt-petre it 

 contains, until a further supply is obtained. 



At Peter Moser's, on Lafferty creek, the mixture of the soil, derived, in 

 part, from the cavernous limestone, and in part from the white sandstone, 

 produces excellent oats, and is capable of yielding 40 to 50 bushels of corn 

 to the acre, and 800 to 1000 pounds of raw cotton in the seed, and in very 

 favorable seasons even as high as 1500 pounds. 



As the cotton loses about two-thirds in cleaning and freeing it from seed, 

 the land may be said to yield from 250 to 350 pounds of clean ginned cot- 

 ton to the acre. It is the washings from the adjacent hills of limestone 

 that cause the land to produce so much better than its first appearance, 



