134 GEOLOGY OF ILLINOIS. 



Economical Geology. 



Coal. — McCracken's, on Lake Fork, is the only place where coal in 

 any quantity has been taken out, and it is only when the creek is dry 

 that this can be advantageously worked. The coal is seventeen inches 

 thick and of good quality ; it is dug out at several other places on Lake 

 Fork, and has also been found on the head of Dry Fork. The other 

 coal beds seen iu this county are too thin to be worth working. Shafts 

 have been sunk in the drift clays for coal east of Greenville, but in 

 order to reach any valuable coal bed they will have to go about 225 to 

 to 300 feet or more below the general surface of the county. 



Building Material. — The only really good building rock is the Shoal 

 creek limestone, of which Tobias Files and Mr. Beams have good 

 quarries. The sandy limestone No. 43 is also good for building pur- 

 poses, and it may be procured one mile south-west of James Vallen- 

 tine's, on a branch of Dry Fork. Plenty of good limestone for lime 

 can be procured ou Lake Fork, on the head of Dry Fork and on Shoal 

 creek near the north county line. 



Fire-clay. — No. 38 may prove to be a good material for fire-brick, and 

 good clay for common bricks can be everywhere procured. 



Water. — Springs are scarce. Good water can generally be procured 

 at twenty to thirty feet beneath the surface. 



Soil and Agriculture. — On the mounds and white oak ridges the soil 

 generally inclines to a red color ; on the fiats it' is of a whitish or gray 

 color and often quite sandy. The richest soil is that of the bottoms, 

 next the high mounds, then the prairie in the south-west part of the 

 county, and next succeed the white oak lands and the flats. There is a 

 small area of very good limestone soil near Locust Fork, with a growth 

 of red oak, white oak, shell bark hickory, elm, hackberry, laurel oak, 

 black oak, black walnut, mulberry, red bud, sassafras, and honey locust. 

 The average yield of wheat is good, occasionally varying from fifteen 

 to thirty bushels per acre ; of corn, thirty to forty, very rarely on the 

 best mound slopes reaching seventy five bushels per acre. • 



