HEXEY COUNTY. 199 



Superficial Deposits. The drift clays of Henry county run from ten 

 to fifty or sixty feet in thickness. These are the common yellow and 

 blue clays underlaying the soil over most of our northern prairies. 

 No fossils of any note have been discovered in these clays, so far as I 

 know. ZS'o beds of coarse gravel were noticed ; no drift copper or galena 

 has been picked up in the county, as in some of the counties farther 

 north. Few boulders were observed lying over the prairies. In the 

 valley of Green river, near its mouth, and in some of the ravines, an 

 occasional boulder may be found washed out of the denuded soil and 

 clay. Indeed the Edwards and Green rivers, in much of their courses, 

 hardly show even fine pebbles along their banks. 



The alluvial deposits, however, are very marked in the Green river 

 swamp lands, and in certain curious sand ridges and hills in the north- 

 eastern part of the county. Xo regular peat beds seem to exist in these 

 swamps 5 but the tough sward of many grasses and sedges scarcely pre- 

 vent one from sinking into the oozy muck and black vegetable mud 

 covering these fresh-water marshes. For some cause the peat mosses 

 have not flourished here as in the Whiteside county sloughs ; but a 

 good illustration of the origin of the prairies, according to Professor 

 LESQUEKEUX'S theory, may be seen almost anywhere along these Green 

 river swamp lands. The sand hills of this swampy region present a 

 more curious phenomenon still. Chains and curious-shaped round hills, 



Ft. In. 

 No. 8 Clay shale, or fire clay 1 3 



Xo. 9 Blue shale : 10 



Xo. 10 Black shale 6 



Xo. 1 1 Coal 3 g 



This seam has a parting of dark shale of variable thickness, and I am inclined to regard it as No. 2, 

 which is frequently separated by a shale parting. The coal is also a rather soft and light coal, more 

 like Xo. 2 than any other, though it contains more pyrite here, than is usually found in it at more 

 southern localities. 



At Atkinson a coal seam about three feet in thickness has been opened on the eastern borders of the 

 town, where it lies about fifteen feet below the surface, and from this point in a southwesterly direc- 

 tion it outcrops along the bluffs of Spring creek for a 'distance of about seven miles. Mowbray, 

 Wtiatherspoon. Welch, Morrow, Shearer and Torpenning's mines are all on this outcrop. The coal 

 averages about three feet feet in thickness, and has an excellent roof of hard, black slaty shale, pass- 

 ing upward into a blue clay shale containing nodules of ironstone and blue limestone. The roof shales 

 are locally tilled with Ariculopecten rectolaterarea and Productus muricatu*. The nodules of limestone 

 and clay ironstone contain Productus Prattenianus, Pleurotomaria percarinata, P. Mvntfortianug, 

 Xacrocheilm, and a minute spiral shell like Polyphemopsis. I have no hesitation in referring this coal 

 t<> Xo. 3 of the Illinois river section, and it shows a regularity in the development of our workable 

 coals along the north-western borders of the coal field that could hardly have been expected. The 

 coal obtained from this seam has a tendency to split into thin layers, with partings of charcoal, and is 

 a harder coal thaii that obtained from Xo. 2. and quite unlike that from either of the lower seams . 



On Mud creek, a few miles further east, another coal is said to outcrop, which is probably Xo. 4 of 

 the general section, and at Sheffield. Kewanee and Galva. Xo. 6 with its characteristic parting of clay 

 shale, is found, thus completing the range of our most valuable coals, and showing their full develop- 

 ment within the limits of Henry county. The general trend of their outcrop is from north-east to 

 south-west, and the dip of the strata is to the south-eastward, but at a very slight angle. In closing 

 these brief notes on Henry county. I desire to acknowledge my obligations to A. W. PEUKY. Esq., of 

 Geneseo, who placed himself and whatever conveyance was required at my disposal, and kindly 

 acted as both guide and commissary during my stay in the county. A. H. W. 



