636 GEOLOGY OF CENTRAL WISCONSIN. 



spreads widely over northwestern Junean county and into the adjoin- 

 ing counties of Jackson and Wood. Underneath the peat of this 

 marsh tongue, and along the hanks of a dry run east of the mai-sh, 

 bog ore occurs in some quantity. The best ore is found on the S. E. 

 qr. of Sec. 21-, T. 18, R. 3 E., on "land belonging to Mr. J. T. Kings- 

 ton, where it lies at about 3 feet below the surface of the marsh, be- 

 ing covered by peat and peaty marsh mud. It is seen in the bottom 

 of a ditch for some 40 rods, and can be raised by the crowbar in large 

 firm blocks. These are very porous, but between the pores show a 

 dark brown, very hard, fibrous," silky- lustred limonite. Immediately 

 over the hard ore, in places, is a sand or shot ore, composed of rolled 

 grains of limonite. The thickness is reported at 2^ feet. The fol- 

 lowing analysis shows the composition of a sample (1356) averaged 

 from a considerable quantity: silica, 8.62; alumina, 3.77; iron perox- 

 ide, 71.40; manganese oxide, 0.27; lime, 0.58; riiagnesia, trace; phos- 

 phoric acid, 0.21; sulphur, 0.02; organic matter, 1.62; water, 

 13.46^99.85: metallic iron, 49.98. Following the stream south- 

 ward into the N. E. qr. of Sec. 25, the ore grows much leaner, being 

 mingled with sand (1356|-). The same sandy ore is seen along the 

 side of a dry run on the IST. W. qr. of Sec. 30, T. 18, R. 4 E., an aver- 

 ago sample yielding only 16.09 per cent, of metallic iron. Mr. 

 Kingston's ore is certainly an excellent one, and the marsh is well 

 worthy of further investigation. 



At Point Bass, Wood county, on the west bank of the Wisconsin 

 river, near the center of Sec. 10, T, 21, R. 5 E., on land belonging to 

 the Hon. Moses M. Strong, a porous bedded limonite is exposed in the 

 river bank, 15 feet above the water. The exposure extends along for 

 some 50 feet, and appears to be some 8 feet in thickness, the upper 

 3 feet being a porous but quite pure ore, containing some 50 per 

 cent, of metallic iron. Two hundred feet down stream a cutting into 

 the river bank shows that the ore does not continue in that direction. 

 At several points on the east bank of the Wisconsin, north of 

 Grand Rapids, on Sec. 4, T. 22, R. 6 E., and Sec. 34, T. 23, R. 6 E., 

 small openings show ore just like that described. At one of, these 

 points, on Mr. McGrrath's land, the ore is seen with a thickness of 20 

 inches, very evenly and thinly bedded, and extending over an area of 

 about 75 feet square. The following analysis, made by Mr. Oliver 

 Matthevv's, a student of the Metallurgical Department of the State 

 University, shows the composition of an averaged sample: silica, 

 4.81; alumina, 1.00; irqn peroxide, 73.23; lime, 0.11; magnesia, 

 0.25; sulphuric acid, 0.07; phosphoric acid, 0.10; organic matter, 

 5.88; water, 14.24=99.69: metallic iron, 51.26. 



