CLINTON IRON ORE DEPOSIT. 329 



eastward; and north of this, it is again northward. This, in connec- 

 tion with the fact that the thickest portion of ore occurs at the highest 

 elevation, near the center of the deposit, seems to indicate that appre- 

 ciable, though slight, flexures of the strata have taken place at this 

 point since their original deposition. 



FIG. 40. 



NORTH AND SOUTH SECTION THROUGH THE IKON ORE DEPOSIT, IRON RIDGE. 

 1. Cincinnati Shale. 2. Iron Ore. 3. Niagara Limestone. 



The ore, as a whole, must be classed with the hematites, although 

 it contains a notable amount of water in combination, and gives a 

 streak varying from a dirty red to a yellowish brown, and, except the 

 upper layer, which differs from the main body, seldom gives a bright 

 scarlet streak or powder. The hydration is not uniform, however, 

 and is most marked where the ore is most exposed, and seems to be a 

 process in progress, rather than an original characteristic. The water 

 collected in, or issuing from, the mines is colored to a bright scarlet, 

 although a spring issuing beneath is almost free from indications of 

 iron, as indeed are all the springs in the vicinity. They cannot be 

 relied upon, then, to indicate the presence of this iron deposit. The 

 ore consists chiefly of small lenticular concretions, whose average 

 diameter is about one twenty -fifth of an inch. They are less uniform 

 in size than would appear to casual observation, being of all dimensions, 

 from one tenth of an inch in diameter to those that are very minute. 

 There occur also in all of the layers, but more numerously in the 

 lower ones, larger concretions which are usually more or less lenticu- 

 lar in form, though frequently otherwise. These seem to be largely 

 composed of argillaceous material. From this concretionary or 

 oolitic structure, the ore receives its popular names, " seed ore," and 

 "shot ore." The concretions are bound together by just enough of 

 adhesive ore powder to give the mass a somewhat firm coherence, and 

 the result is a soft, granular rock. The little lens-shaped concretions 

 lie, as would naturally be anticipated, chiefly upon their sides, giving 

 to the rock a ready cleavage in a horizontal direction. These facts, 

 together with the vertical joints and frequent bedding lines, render 

 mining remarkably easy. The prevailing color is a dark reddish 

 brown. At certain points it becomes purplish and even bluish, as at 

 the Mayville Ore Bed, where the term " blue ore " is applied. 



The top layer, from 3 to 8 inches thick, differs markedly from the 



