Minesota Mine
Encyclopedia
The Minesota Mine is a former copper
mine near Rockland, Ontonagon County
in the Upper Peninsula
of the U.S. state
of Michigan
. The Minesota (the single "n" in the name was a mistake in the original incorporation papers) was one of the most productive and famous early mines in the Michigan Copper Country
.
in a pit dug by aboriginal miners. In the pit was growing a hemlock nearly 400 years old by the number of growth rings. Mining began in 1848, and from 1855 through 1862, the Minesota was the most productive copper mine in the United States. The mine had ten shafts, the deepest of which extended to a depth of 1200 feet (366 m). In 1856, miners tunneled into a 527-ton (478 mt) mass of native copper, the second-largest such mass found in the Copper Country
. Besides masses of copper recovered through hand-sorting, the mine ran a small stamp mill
to recover finer-grained copper in ore that ran 3%.
In 1870, the rich massive copper had been worked out, and the depth of the mine shafts had reached the limit of the hoisting equipment. At the same time, the price of copper dropped to $0.19 per pound, down from a high of $0.55 in 1864. Rather than invest in new equipment and explore for new ore bodies, the company stopped working the mine, and turned it over to tributers – independent miners who paid for the privilege of mining, usually paying a share of the ore they took out. The mine continued to be profitable to tributers, who took out 270 tons (245 mt) of copper in 1870, the same year that the mine closed. In 1876, the Minesota company paid a final dividend and went out of business, having paid a total of $1.82 million in dividends, versus $456,000 in assessments.
Through the end of the 1800s tributers continued to pick copper out of that part of the old workings that remained above water level. Through 1888, the mine had yielded 17,352 tons (15,742 mt) of copper, as well as 533 pounds of silver. In 1899 the property was acquired by the Michigan Mining Company, which also bought the nearby Rockland and Superior mines. In 1903, the Michigan company opened the Calico amygdaloid, which held 3% copper ore, and outcropped on the Minesota property only 140 feet (43m) from the outcrop of the Minesota fissure vein.
mines, the mineral sought was native copper. Some silver
was said to have been recovered in the upper workings. Other minerals in the ore, but which had no economic importance include quartz
, calcite
, epidote
, pumpellyite
, chlorite
and feldspar
.
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
mine near Rockland, Ontonagon County
Ontonagon County, Michigan
-National protected areas:* Keweenaw National Historical Park * Ottawa National Forest -Demographics:As of the census of 2000, there were 7,818 people, 3,456 households, and 2,225 families residing in the county. The population density was 6 people per square mile . There were 5,404 housing units...
in the Upper Peninsula
Upper Peninsula of Michigan
The Upper Peninsula of Michigan is the northern of the two major land masses that make up the U.S. state of Michigan. It is commonly referred to as the Upper Peninsula, the U.P., or Upper Michigan. It is also known as the land "above the Bridge" linking the two peninsulas. The peninsula is bounded...
of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. The Minesota (the single "n" in the name was a mistake in the original incorporation papers) was one of the most productive and famous early mines in the Michigan Copper Country
Copper Country
The Copper Country is an area in the Upper Peninsula of Michigan in the United States, including all of Keweenaw County, Michigan and most of Houghton, Baraga and Ontonagon counties. The area is so named as copper mining was prevalent there from 1845 until the late 1960s, with one mine ...
.
History
The Minesota fissure vein was discovered in 1847 when prospectors found a six-ton (5.4 mt) mass of native copperNative copper
Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...
in a pit dug by aboriginal miners. In the pit was growing a hemlock nearly 400 years old by the number of growth rings. Mining began in 1848, and from 1855 through 1862, the Minesota was the most productive copper mine in the United States. The mine had ten shafts, the deepest of which extended to a depth of 1200 feet (366 m). In 1856, miners tunneled into a 527-ton (478 mt) mass of native copper, the second-largest such mass found in the Copper Country
Copper Country
The Copper Country is an area in the Upper Peninsula of Michigan in the United States, including all of Keweenaw County, Michigan and most of Houghton, Baraga and Ontonagon counties. The area is so named as copper mining was prevalent there from 1845 until the late 1960s, with one mine ...
. Besides masses of copper recovered through hand-sorting, the mine ran a small stamp mill
Stamp mill
A stamp mill is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation....
to recover finer-grained copper in ore that ran 3%.
In 1870, the rich massive copper had been worked out, and the depth of the mine shafts had reached the limit of the hoisting equipment. At the same time, the price of copper dropped to $0.19 per pound, down from a high of $0.55 in 1864. Rather than invest in new equipment and explore for new ore bodies, the company stopped working the mine, and turned it over to tributers – independent miners who paid for the privilege of mining, usually paying a share of the ore they took out. The mine continued to be profitable to tributers, who took out 270 tons (245 mt) of copper in 1870, the same year that the mine closed. In 1876, the Minesota company paid a final dividend and went out of business, having paid a total of $1.82 million in dividends, versus $456,000 in assessments.
- "It is true that such recollections must be taken with a grain of salt, as the miner sees through the vista of backward years with an eye that wonderfully magnifies mineral values, and in the course of time any abandoned mine gets the name of having been rich; but in the case of the Minnesota there is reliable evidence that the mine was abandoned through faint-heartedness, and not because it was worked out."
-
- - Horace J. Stevens, 1902, The Copper Handbook, p.196-197.
-
Through the end of the 1800s tributers continued to pick copper out of that part of the old workings that remained above water level. Through 1888, the mine had yielded 17,352 tons (15,742 mt) of copper, as well as 533 pounds of silver. In 1899 the property was acquired by the Michigan Mining Company, which also bought the nearby Rockland and Superior mines. In 1903, the Michigan company opened the Calico amygdaloid, which held 3% copper ore, and outcropped on the Minesota property only 140 feet (43m) from the outcrop of the Minesota fissure vein.
Geology
Like almost all other Copper CountryCopper Country
The Copper Country is an area in the Upper Peninsula of Michigan in the United States, including all of Keweenaw County, Michigan and most of Houghton, Baraga and Ontonagon counties. The area is so named as copper mining was prevalent there from 1845 until the late 1960s, with one mine ...
mines, the mineral sought was native copper. Some silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
was said to have been recovered in the upper workings. Other minerals in the ore, but which had no economic importance include quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
, calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
, epidote
Epidote
Epidote is a calcium aluminium iron sorosilicate mineral, Ca2Al2O, crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often...
, pumpellyite
Pumpellyite
Pumpellyite is a group of closely related sorosilicate minerals:*pumpellyite-: Ca2MgAl2[2|SiO4|Si2O7]·*pumpellyite-: Ca2Fe2+Al2[2|SiO4|Si2O7]·*pumpellyite-: Ca22[2|SiO4|Si2O7]·H2O...
, chlorite
Chlorite
The chlorite ion is ClO2−. A chlorite is a compound that contains this group,with chlorine in oxidation state +3. Chlorites are also known as salts of chlorous acid.-Oxidation states:...
and feldspar
Feldspar
Feldspars are a group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust....
.