LASALLE COUNTY. 43 



Feet. 



No. 1. Bituminous shale 10 



No.2. Coal (Streator seam) 8 to 9 



No.3. Shale and fire-clay 10 



No. 4. Black shale 4 



No. 5. Sandstone and sandy shale 15 to 20 



The coal in Patterson's shaft is about 80 or 90 feet below the 

 Streator seam, and the space between the sandstone at the base of 

 the foregoing section and coal No. 2 is mainly occupied by argilla- 

 ceous and bituminous shales, with one or more bands of hard, im- 

 pure limestone. No record of the Patterson shaft was kept, and no 

 exposure was found where a detailed section from coal No. 2 to the 

 sandstone under the .Streator coal could be made. 



As coals No. 2 and 4 are nowhere exposed at the same point on 

 the Vermilion, a superficial examination might lead to the conclu- 

 sion that they were not distinct seams, but the difference in the 

 quality of the coal they afford, and in the character of the roof 

 shales, and moreover the presence of both seams on Sec. 24, T. 32, 

 B. 2, where a boring was made to demonstrate the presence of the 

 lower seam, leaves no room to doubt the separate position which 

 they occupy. Hence we are juslified in the conclusion that there 

 are three coals outcropping on the Vermilion, all of which are 

 worked at the present time ; No. 2 in the shaft at Patterson's, No. 

 4 in the vicinity of Lowell, and No. 7 at Kirkpatrick's ford, and in 

 the vicinity of Streator. 



Some diversity of opinion has existed with those who have given 

 special attention to the geology of this county, in regard to the 

 position which the Streator coal occupies in the general section of 

 the coal strata of this State, but from a careful examination of all 

 the outcrops of the seam from Kirkpatrick's ford, to the last point 

 where it appears above the river level above Streator, I am fully 

 satisfied that it is the exact equivalent of coal No. 7 of the general 

 section. The coal which it affords is perhaps rather better in qual- 

 ity than that hitherto obtained from the upper seam in the shafts 

 about Peru and LaSalle, but it has been generally neglected in all 

 the shafts where Nos. 2 and 5 are found, and therefore its 

 average quality at those points has not been fairly determined. 

 It ranges in thickness from 5 to 8 feet, with an average of about 

 6 feet, and it probably affords as much coal at the present time as 

 No. 5, which is the next in average thickness, and the one most 

 extensively mined in the central part of the county. 



