LASALLE COUNTY. 



home, and for export to the north, where no coal is to be found 

 either in this or adjacent States. 



The local examinations made during the past year were mainly 

 confined to the southern half of the county, and were especially di- 

 rected to the determination of the number, thickness and relative 

 value of the coal seams to be found within its borders. 



The axis of disturbance which has already been mentioned as 

 crossing the county from northwest to southeast, follows the course 

 of the Vermilion river from its mouth to the Livingston county line, 

 and probably beyond, and has produced a marked irregularity in the 

 distribution of the productive coal seams, and rendered their deter- 

 mination somewhat more difficult than would be the case if the beds 

 had remained in their normal position. 



North of the Illinois river, and east of this axis, no productive 

 mines have been opened, except on the outcrop of the lower seam, 

 where it has been worked to a limited extent for a local supply, nor 

 is it probable that any extensive coal mines will ever be opened in 

 that part of the county, although there is a considerable area there 

 that is underlaid by thin outliers of the lower Coal Measures. 



South of the Illinois, and east of the Vermilion, there is quite an 

 extensive area underlaid in part by three productive coal seams, 

 though, so far as I was able to determine, not more than two of 

 these could be found at the same locality. At Lowell the Vermilion 

 river flows over massive beds of Trenton limestone, and this forms 

 the lower portion of the river bluffs, extending on the west side to 

 the height of twenty feet or more above the river. The limestone 

 is here directly overlaid by the Coal Measures fifty feet or more in 

 thickness, showing the following section: 



Feet. 



No. 1. Sandstone partially exposed 8 to 10 



No. 2. Shale, with bands of Septaria 10 to 12 



No. 3. Black sheety shale 2 to 3 



No. 4. Clay shale 6 to 8 



No.5. Coal No. 4 3 



No. 6. Green and purple shales 8 to 10 



No. 7. Trenton Limestone 15 to 20 



The sandstone at the top of the foregoing section was only ex- 

 posed in the top of the bluff about half a mile below the bridge at 

 Lowell, and is probably the same sandstone which underlies the 

 Streator coal at points further up the river. A band of limestone 

 occurs somewhere in the bluff at this point, composed mainly of 

 crinoidal stems about half an inch in diameter, a specimen of which 

 was found here by the Hon. Elmer Baldwin. I did not find it in 



