GEOLOGY OF I^A SALLE COUNTY. 27 



and Northern Illinois, and the upper La Salle coal, No. 

 42, in the section, is No. 7 of the Illinois section." On 

 pao-e 42, Vol. VII., of the Geological Report, we read; 

 "On Section 24, Township 32, Rang-e 2 east, the sec- 

 tion observed was similar to that at Lowell. ^' 

 The section here is as follows: (1) Sandstone, ten to 

 twelve feet; (2) shale, six to twelve feet; (3) black 

 slate, two feet; (4) shale and limestone, four feet; (5) 

 black slate, six feet; (6) clay slates, fifteen to twenty 

 feet; (7) covered space (slope), four to five feet; (8) 

 coal in river bed, one and one-half to two feet. This 

 coal he calls No. 4, while he would call the first black 

 slate coal 5, and has apparently no use for the lower 

 black slate, No. 5, above. But the most striking argu- 

 ment is the following, same pagers above: " Porty- 

 seven feet below the base of the foregoing section (the 

 bed of the river) another seam of coal, thirty inches 

 thick, was found by boring at this point, which I have 

 no doubt is coal No. 2 of the general section and the 

 lowest seam in the shafts at La Salle and Peru." To 

 the last conclusion we assent, but we deny that a bed 

 of coal was found forty -seven feet below the coal 

 found in the river. The boring was some distance 

 from that place, and that any one who has spent a day 

 on the Big Vermillion should for a moment pretend to 

 identify coal seams by the depth at which he finds 

 them, when he can follow a seam and sec. it sevent}^- 

 five feet above the water, and within forty rods see it 

 sink beneath the river to reappear again farther south. 

 This difference in elevation does not ■ prove that the 

 seam at one point is not the same as at another; in fact, 

 the level at which a seam lies has nothing to do with 

 what it is, especially in a disturbed region like the Big 

 Vermillion valley. It is not by the levels at w^hich 

 they occur, but by their relation to other strata that 

 we must decide the question as to the identity or dif_ 



