THE MINERAL INDUSTRY OF WISCONSIN 
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Uses, in decreasing order of quantity, included railroad ballast, roofing
granules, concrete aggregate and roadstone, silica brick, and abrasives.
Crushed and broken basalt, used for roofing granules, railroad ballast, and
concrete aggregate and roadstone, was produced in Marinette and Polk Counties.
Calcareous marl was produced in Burnett County for agricultural purposes.

 Output of dimensiOn stone, consisting of limestone, granite, and sandstone,
decreased 20 percent in quantity and 10 percent in value. Quantity decreases
were recorded for all types of dimension stone whereas only limestone decreased
in value. 
 Limestone constituted 87 percent in quantity and 39 percent in value of
the total State dimension stone production, although output decreased 22
percent in quantity and 30 percent in value from that of 1966. Major reason
for the decline was a reduction in sales of house stone veneer, which accounted
for 42 percent of the total dimension limestone output value, compared with
62 percent in 1966. Other uses, in descending order of value, were rough
construction, rubble, sawed stone, cut stone, flagging, and rough architectural
stone. Dimension limestone was produced in five counties by 27 companies.
The two leading counties were Fond du Lac and Waukesha, accounting for about
91 percent of the State total value of dimension limestone. Wisconsin accounted
for about 15 percent in quantity and 9 percent in value of the Nation's 1967
dimension limestone output, ranking second in quantity and third in value
among the States. 
 Granite comprised 10 percent in quantity and 59 percent in value of all
dimension stone produced in the State. Output of dimension granite decreased
1 percent in quantity and increased 9 percent in value from that of 1966.
Dimension granite was produced by seven companies in Ashland, Marathon, Marinette,
and Marquette Counties. Rough and dressed monumental stone accounted for
about 91 percent of the total output. The remainder was sold for rubble and
architectural purposes. Of all dimension stone, dressed monumental* granite
continued to have the highest average unit value at $26.64 per cubic foot,
an increase of $0.26 from that of 1966. 
 Seven companies in Marathon, Portage, 
Sauk, and Wood Counties produced dimension sandstone for rough construction,
cut stone, flagging, and rubble. Production in 1967 was valued at $50,000
an increase of 3 percent over that of 1966. 
 
 Vermiculite.—Exfoliated vermiculite was produced by Zonolite Division,
W. R. Grace & Co., at Milwaukee from crude material mined outside the
State. The exfoliated material was used for loose fill insulation, lightweight
aggregate in concrete and plaster, and for agricultural purposes. 
 
METALS 
 Iron Ore.—Jackson County Iron Co., a wholly-owned subsidiary of Inland
Steel Co., began initial site preparation late in the year for its new 750,000-ton~per-year
taconite operation near Black River Falls, Jackson County. The Dravo Corp.,
of Pittsburgh, Pa., was awarded the contract for design, engineering, and
construction of the concentrator and pellet plant. This facility was scheduled
to produce pellets containing 65 percent iron, utilizing the Dravo Lurgi
traveling gate pelletizing process, by late 1969. Pellets were expected to
be shipped by rail on a year-round basis to Inland Steel Co.'s Indiana Harbor
Works in East Chicago, md. The Black River Falls operation was expected to
supply approximately 10 percent of Inland Steel Co.'s annual iron ore needs
Exploration activities were conducted on the western portion of the Gogebic
Range by Jackson County Iron Co. in Iron County, and The Hanna Mining Co.
near Mellen, in Ashland County. Depletion tax allowances were granted for
low-grade iron ore mining in the State, reducing the State tax assessment
from $0.37 to $0.25 per ton of concentrates. 
 Iron ore, produced in Minnesota, was shipped by lake vessel from ore docks
operated at Superior by Great Northern Railway Co. and the Northern Pacific
Railway Co. Great Northern Railway Co. completed construction of its 2.5-millionton-capacity
taconite storage area near its Allouez (Superior) docks. This facility, designed
for winter storage of taconite pellets, began receiving unit train shipments
in 1967 from The Hanna Mining Co.'s Butler Taconite Project and from the
National Steel Pellet Plant, both located on the Mesabi Range in Minnesota.