Copper mining in Michigan
Encyclopedia
While it originated thousands of years earlier, copper mining in Michigan became an important industry in the 19th and early 20th centuries. Its rise marked the start of copper mining as a major industry in the United States.
, copper
is found almost exclusively in the western portion of the Upper Peninsula, in an area known as the Copper Country
. The Copper Country is highly unusual among copper-mining districts, because copper is predominantly found in the form of pure copper
metal (native copper
) rather than the copper oxides or copper sulfide
s that form the copper ore at almost every other copper-mining district. The copper deposits occur in rocks of Precambrian
age, in a thick sequence of northwest-dipping sandstone
s, conglomerates
, ash beds, and flood basalt
s associated with the Keweenawan Rift.
Although native copper was the dominant ore mineral, chalcocite
(copper sulfide) was sometimes present, and, especially in the Mohawk mine, copper arsenide minerals such as mohawkite and domeykite
. Gangue
minerals included calcite
, quartz
, epidote
, chlorite
, and various zeolite
s. A number of copper mines also contained a notable amount of silver
, both in native form and naturally alloyed with the copper. Halfbreed is the term for an ore sample that contains the pure copper and pure silver in the same piece of rock; it is only found in the native copper deposits of the Upper Peninsula of Michigan.
were the first to mine and work the copper of Lake Superior
and the Keweenaw Peninsula
of northern Michigan
between 5000 BCE and 1200 BCE. The natives used this copper to produce tools. Archaeological expeditions in the Keweenaw Peninsula and Isle Royale
revealed the existence of copper producing pits and hammering stones which were used to work the copper. Fringe writers have suggested that as much as 1.5 billion pounds of copper was extracted during this period, but archaeologists consider such high figures as "ill-constructed estimates" and that the actual figure is unknown.
By the time the first European explorers arrived, the area was the home of the Chippewa people, who did not mine copper. According to Chippewa traditions, they had much earlier supplanted the original miners. The first written account of copper in Michigan was given by French missionary Claude Allouez in 1667. He noted that Indians of the Lake Superior
region prized copper nuggets that they found there. Indians guided missionary Claude Dablon
to the Ontonagon Boulder
, a 1.5-ton piece of native copper along the Ontonagon River
. When American prospectors arrived in the 1840s, pieces of copper were found in streams or on the ground. The copper pits abandoned by Native Americans led early miners to most of the first successful mines.
The Michigan State Geologist Douglass Houghton
(later to become mayor of Detroit
) reported on the copper deposits in 1841, which quickly began a rush of prospectors. Mining took place along a belt that stretched about 100 miles southwest to northeast through Ontonagon
, Houghton
, and Keweenaw
counties. Isle Royale
, on the north side of Lake Superior
, was extensively explored, and a smelter built, but no mining of any importance took place there. Some copper mineralization was found in Keweenawan rocks farther southwest in Douglas County, Wisconsin, but no successful mines were developed there.
Copper mining in the Upper Peninsula boomed, and from 1845 until 1887 (when it was exceeded by Butte, Montana
) the Michigan
Copper Country
was the nation's leading producer of copper. In most years from 1850 through 1881, Michigan produced more than three-quarters of the nation's copper, and in 1869 produced more than 95% of the country's copper.
, began operations in 1845, and many others quickly followed. These first mines worked copper-filled fissure veins
that cut across stratigraphic layers.
Although the copper-mining region stretched about 100 miles from northeast to southwest, the most productive early mines, working fissure veins, were those at the north end in Keweenaw County (such as the Central, Cliff, and Phoenix mines), or at the south end in Ontonagon County (such as the Minesota Mine
).
In Keweenaw County, the fissure lodes were nearly vertical mineralized zones with strike nearly perpendicular to that of the enclosing basalts and conglomerates. In Ontanogan county, by contrast, the fissures had strikes nearly parallel to, and dips slightly steeper than, the surrounding beds.
The miners sometimes found masses of native copper
up to hundreds of tons. To extract a single mass of copper, miners could spend months chiseling it into pieces small enough to hoist out of the mine. Although they were pure copper, removing the masses took a great deal of effort, and was sometimes not even profitable. The majority of the copper recovered was "barrel copper" (pieces broken from the rock and hand sorted in the "rock house," and shipped to the smelter in barrels), and finer copper broken loose from the rock in stamp mills and separated by gravity in "buddles" or "jigs."
-pebble conglomerates
and in the upper zones of basalt lava flows (locally called amygdaloids). Although amygdaloid and conglomerate deposits tended to be lower-grade than the fissure deposits, they were much larger, and could be mined much more efficiently, with the ore blasted out, hoisted to the surface, and sent to stamp mills located at a different site. Amygdaloid and conglomerate mining turned out to be much more productive and profitable than fissure mining, and the majority of highly successful mines were on amygdaloid or conglomerate lodes. The first mine to successfully mine a strataform ore body was the Quincy Mine
in 1856. The most productive deposit, the Calumet conglomerate, was opened by the Calumet and Hecla mining company in 1865.
While the most successful fissure mines had been at the north and south ends of the district, the conglomerate and amygdaloid mines, which produced the great majority of Michigan copper, were concentrated in the center of the district, almost all in Houghton County. The most productive conglomerate and amygdaloid mines were located along a strip about two miles wide and 24 miles long, from the Champion mine on the southwest to the Ahmeek mine on the northeast, passing through the towns of Houghton
, Hancock
, and Calumet
.
In the early 20th century, copper companies began to consolidate. With very few exceptions, such as the Quincy Mine
at Hancock
, the mines in the Copper Country came under the control of two companies: the Calumet and Hecla Mining Company
north of Portage Lake, and Copper Range Company
south of Portage Lake.
Annual production peaked in 1916 at 266 million pounds (121,000 metric tons) of copper. Most mines closed during the great depression
as a result of depressed copper prices. Many mines reopened during World War II
, when wartime demand pushed copper prices higher. The end of the war brought an end to high prices, and nearly all companies closed, leaving only the Calumet and Hecla, Quincy, and Copper Range mining companies. Both Calumet and Hecla and Quincy survived largely by reprocessing the stamp sand
left from older mining operations, leaching out copper left by more primitive processing techniques.
By 1968 the formerly great Calumet and Hecla was purchased by Universal Oil
and became the company's Calumet division. By this time the Calumet and Hecla's original conglomerate workings had been abandoned and stamp sand reclamation had ended. The mines did not even produce enough copper to supply the company's internal demand. The company opened several new shafts and dewatered several old ones in hopes of finding additional wealth, but none were successful. Later that year, Calumet and Hecla's mine workers went out on strike, and the new owners closed the mines for good. Only the Copper Range company's White Pine mine remained open, and its ore was mostly copper sulfides, rather than native copper. Michigan's native copper industry was essentially dead, after producing 11 billion pounds (5.0 million metric tons) of copper.
Several companies attempted to reopen copper mines during the next two decades, including attempts by the Homestake Mining Company
. None of these attempts lasted more than a couple of years or proved profitable.
) used a portion of its budget surplus to build The Calumet Theatre
, an opulent opera house which hosted famous plays and acts from across the world. Many wealthy mine managers built mansions which still line the streets of former mining towns. Some towns which existed primarily due to copper mining include Calumet, Houghton, Hancock, and Ontonagon. As the mines began to close, the Copper Country lost its major economic base. The population declined sharply as miners, shop owners, and others supported by the industry left the area, leaving many small ghost towns along the mineral range.
Tourism and logging are now the major industries. The copper industry left many abandoned mines and buildings across the Copper Country. Some of these are now part of the Keweenaw National Historical Park
. Some mines, such as the Quincy Mine
and the Delaware Mine, are open as tourist attractions. Many other mining lands are simply left abandoned.
Copper mining also took a significant impact on the environment. Mine rock processing operations left many fields of stamp sand
, some of which grew so large as to become hazards to navigation in the Keweenaw Waterway
. Most of these sterile sands are now superfund
sites which are slowly being rehabilitated. Mines also required a great deal of wood, largely for supports in mine tunnels. Virtually every part of the Copper Country was cleared of timber, to the extent that only one small area of old-growth forest (the Estivant Pines
) is left. Formerly cleared lands have been left to regrow, to the extent that many parcels of land are now being harvested on a limited basis by timber and paper companies.
at the south end of the Copper Country in Ontonagon County
had been known since the 1800s. But the ore grades were too low, the ore mineral particles too small, and the copper was largely in sulfides instead of native copper. All these conditions made the shale deposits uneconomical, although repeated attempts were made to mine the shale at the Nonesuch mine
.
In 1955 the Copper Range Company
began large-scale mining at the White Pine mine, near the old Nonesuch mine. The deposit is a stratiform deposit in the lower 15 m of the Proterozoic
Nonesuch Shale
and the upper 2 m of the underlying Copper Harbor Conglomerate. The principal ore mineral was chalcocite
, although native copper
predominated in the lower part of the beds. The mine was very successful, producing more than 1.8 million metric tons of copper during its life. The White Pine mine, the last major copper mine in Michigan, shut down in 1995.
The company applied to government agencies to continue mining by in-situ leaching, using sulfuric acid
to recover an additional 900 million pounds of copper by SX-EW
. The Michigan Department of Environmental Quality approved the permit in May 1996, and White Pine installed a pilot in-situ leaching project.http://www.deq.state.mi.us/pr/1996releases/960528.html Native Americans of the Bad River Indian Reservation in northern Wisconsin
blockaded rail shipments of sulfuric acid to the mine (see Bad River Train Blockade
); the mine began receiving acid shipments by truck. The U.S. Environmental Protection Agency (EPA), which had previously held that it had no role in the permitting, reversed itself, and stated that White Pine would have to apply for a federal permit. White Pine, which had already started to recover copper from the pilot project, suspended solution mining in October 1996, and applied for to the EPA for the permit.http://www.umich.edu/~snre492/pmaj.html In May 1997 the company withdrew the EPA permit application, saying that further permitting delays had made the project uneconomical, and announced plans to begin reclamation of the mine site.
The tailings impoundment at the White Pine Mine is presently the site of significant environmental degradation. The University of Montana undertook extensive efforts to restore and revegetate the barren landscape from 1997-1999, but it is unclear whether this has been successful. The university has published a detailed report of its project.http://ecorestoration.montana.edu/mineland/histories/metal/white_pine/default.htm Satellite images are available at (46°47′17.91"N 89°31′47.97"W).
-copper
mine called the Eagle mine project
in the Yellow Dog Plains
, about 25 miles northwest of Marquette
, in Michigan
's Upper Peninsula. Construction work started in 2010, with production beginning at the end of 2013 and to continue up to 8 years. After mining is finished the site will be reclaimed. The mine will produce separate nickel and copper concentrates containing an average of 17,300 and 13,200 tonnes per year of nickel and copper respectively. Ores will be processed at the Humboldt Mill in Champion, Michigan for processing. The ore deposit is estimated to contain up to 140 thousand metric tons of nickel and 91 thousand metric tons of copper, as well as platinum, palladium, and cobalt.
Geology
Within the state of MichiganMichigan
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"....
, copper
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...
is found almost exclusively in the western portion of the Upper Peninsula, in an area known as 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 ...
. The Copper Country is highly unusual among copper-mining districts, because copper is predominantly found in the form of pure copper
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...
metal (native copper
Native 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...
) rather than the copper oxides or copper sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
s that form the copper ore at almost every other copper-mining district. The copper deposits occur in rocks of Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
age, in a thick sequence of northwest-dipping sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
s, conglomerates
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
, ash beds, and flood basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
s associated with the Keweenawan Rift.
Although native copper was the dominant ore mineral, chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
(copper sulfide) was sometimes present, and, especially in the Mohawk mine, copper arsenide minerals such as mohawkite and domeykite
Domeykite
Domeykite is a copper arsenide mineral, Cu3As. It crystallizes in the isometric system, although crystals are very rare. It typically forms as irregular masses or botryoidal forms. It is an opaque, white to gray metallic mineral with a Mohs hardness of 3 to 3.5 and a specific gravity of 7.2 to...
. Gangue
Gangue
In mining, gangue is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. The separation of mineral from gangue is known as mineral processing, mineral dressing or ore dressing and it is a necessary and often significant aspect of mining...
minerals included 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:...
, 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,...
, 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...
, 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 various zeolite
Zeolite
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...
s. A number of copper mines also contained a notable amount of 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...
, both in native form and naturally alloyed with the copper. Halfbreed is the term for an ore sample that contains the pure copper and pure silver in the same piece of rock; it is only found in the native copper deposits of the Upper Peninsula of Michigan.
Native American mining
Prehistoric Native AmericansIndigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
were the first to mine and work the copper of Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...
and the Keweenaw Peninsula
Keweenaw Peninsula
The Keweenaw Peninsula is the northern-most part of Michigan's Upper Peninsula. It projects into Lake Superior and was the site of the first copper boom in the United States. As of the 2000 census, its population was roughly 43,200...
of northern 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"....
between 5000 BCE and 1200 BCE. The natives used this copper to produce tools. Archaeological expeditions in the Keweenaw Peninsula and Isle Royale
Isle Royale
Isle Royale is an island of the Great Lakes, located in the northwest of Lake Superior, and part of the state of Michigan. The island and the 450 surrounding smaller islands and waters make up Isle Royale National Park....
revealed the existence of copper producing pits and hammering stones which were used to work the copper. Fringe writers have suggested that as much as 1.5 billion pounds of copper was extracted during this period, but archaeologists consider such high figures as "ill-constructed estimates" and that the actual figure is unknown.
By the time the first European explorers arrived, the area was the home of the Chippewa people, who did not mine copper. According to Chippewa traditions, they had much earlier supplanted the original miners. The first written account of copper in Michigan was given by French missionary Claude Allouez in 1667. He noted that Indians of the Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...
region prized copper nuggets that they found there. Indians guided missionary Claude Dablon
Claude Dablon
Claude Dablon was a Jesuit missionary, born in Dieppe, France.At the age of twenty-one he entered the Society of Jesus, and after his course of studies and teaching in France, arrived in Canada in 1655. He was at once dispatched with Father Chaumonot to begin a central mission among the Iroquois...
to the Ontonagon Boulder
Ontonagon Boulder
The Ontonagon Boulder is a 3,708 pound boulder of native copper originally found in the Upper Peninsula of Michigan, United States, and now in the possession of the Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution...
, a 1.5-ton piece of native copper along the Ontonagon River
Ontonagon River
The Ontonagon River is a river flowing to Lake Superior on the western Upper Peninsula of Michigan in the United States. The main stem of the river is 25 mi long and is formed by a confluence of several longer branches, portions of which have been collectively designated as a National Wild...
. When American prospectors arrived in the 1840s, pieces of copper were found in streams or on the ground. The copper pits abandoned by Native Americans led early miners to most of the first successful mines.
Modern mining industry
Douglass Houghton
Douglass Houghton was an American geologist and physician, primarily known for his exploration of the Keweenaw Peninsula of Michigan.-Early life and education:...
(later to become mayor of Detroit
Detroit, Michigan
Detroit is the major city among the primary cultural, financial, and transportation centers in the Metro Detroit area, a region of 5.2 million people. As the seat of Wayne County, the city of Detroit is the largest city in the U.S. state of Michigan and serves as a major port on the Detroit River...
) reported on the copper deposits in 1841, which quickly began a rush of prospectors. Mining took place along a belt that stretched about 100 miles southwest to northeast through Ontonagon
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...
, Houghton
Houghton County, Michigan
-National protected areas:* Keweenaw National Historical Park * Ottawa National Forest -Demographics:As of the census of 2000, there were 36,016 people, 13,793 households, and 8,137 families residing in the county. The population density was 36 people per square mile . There were 17,748 housing...
, and Keweenaw
Keweenaw County, Michigan
-Demographics:As of the census of 2000, there were 2,301 people, 998 households, and 604 families residing in the county. The population density was 4 people per square mile . There were 2,327 housing units at an average density of 4 per square mile...
counties. Isle Royale
Isle Royale
Isle Royale is an island of the Great Lakes, located in the northwest of Lake Superior, and part of the state of Michigan. The island and the 450 surrounding smaller islands and waters make up Isle Royale National Park....
, on the north side of Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...
, was extensively explored, and a smelter built, but no mining of any importance took place there. Some copper mineralization was found in Keweenawan rocks farther southwest in Douglas County, Wisconsin, but no successful mines were developed there.
Copper mining in the Upper Peninsula boomed, and from 1845 until 1887 (when it was exceeded by Butte, Montana
Butte, Montana
Butte is a city in Montana and the county seat of Silver Bow County, United States. In 1977, the city and county governments consolidated to form the sole entity of Butte-Silver Bow. As of the 2010 census, Butte's population was 34,200...
) the 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"....
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 ...
was the nation's leading producer of copper. In most years from 1850 through 1881, Michigan produced more than three-quarters of the nation's copper, and in 1869 produced more than 95% of the country's copper.
Fissure veins
Commercial production began in 1844 at the Phoenix mine. Most early miners began with little knowledge or planning, and few mines ever saw production, much less profit. The first successful copper mine, the Cliff mineCliff mine
The Cliff mine was the first successful copper mine in the Copper Country of the state of Michigan in the United States. The mine is at the now-abandoned town of Clifton in Keweenaw County. Mining began in 1845, and the Cliff was the most productive copper mine in the United States from 1845...
, began operations in 1845, and many others quickly followed. These first mines worked copper-filled fissure veins
Vein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...
that cut across stratigraphic layers.
Although the copper-mining region stretched about 100 miles from northeast to southwest, the most productive early mines, working fissure veins, were those at the north end in Keweenaw County (such as the Central, Cliff, and Phoenix mines), or at the south end in Ontonagon County (such as the Minesota Mine
Minesota Mine
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 was one of the most productive and famous early mines in the Michigan Copper Country.-History:The Minesota fissure vein was discovered in 1847 when...
).
In Keweenaw County, the fissure lodes were nearly vertical mineralized zones with strike nearly perpendicular to that of the enclosing basalts and conglomerates. In Ontanogan county, by contrast, the fissures had strikes nearly parallel to, and dips slightly steeper than, the surrounding beds.
The miners sometimes found masses of native copper
Native 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...
up to hundreds of tons. To extract a single mass of copper, miners could spend months chiseling it into pieces small enough to hoist out of the mine. Although they were pure copper, removing the masses took a great deal of effort, and was sometimes not even profitable. The majority of the copper recovered was "barrel copper" (pieces broken from the rock and hand sorted in the "rock house," and shipped to the smelter in barrels), and finer copper broken loose from the rock in stamp mills and separated by gravity in "buddles" or "jigs."
Strataform deposits
In the 1850s, mining began on stratiform native copper deposits in felsiteFelsite
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals. Felsite is a field term for a light colored rock that typically requires petrographic examination or chemical analysis for more precise definition...
-pebble conglomerates
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
and in the upper zones of basalt lava flows (locally called amygdaloids). Although amygdaloid and conglomerate deposits tended to be lower-grade than the fissure deposits, they were much larger, and could be mined much more efficiently, with the ore blasted out, hoisted to the surface, and sent to stamp mills located at a different site. Amygdaloid and conglomerate mining turned out to be much more productive and profitable than fissure mining, and the majority of highly successful mines were on amygdaloid or conglomerate lodes. The first mine to successfully mine a strataform ore body was the Quincy Mine
Quincy Mine
The Quincy Mine is an extensive set of copper mines located near Hancock, Michigan. The mine was owned by the Quincy Mining Company and operated between 1846 and 1945, although some activities continued through the 1970s. The Quincy Mine was known as "Old Reliable," as the Quincy Mine Company paid...
in 1856. The most productive deposit, the Calumet conglomerate, was opened by the Calumet and Hecla mining company in 1865.
While the most successful fissure mines had been at the north and south ends of the district, the conglomerate and amygdaloid mines, which produced the great majority of Michigan copper, were concentrated in the center of the district, almost all in Houghton County. The most productive conglomerate and amygdaloid mines were located along a strip about two miles wide and 24 miles long, from the Champion mine on the southwest to the Ahmeek mine on the northeast, passing through the towns of Houghton
Houghton, Michigan
Houghton is a city in the U.S. state of Michigan's Upper Peninsula and largest city in the Copper Country on the Keweenaw Peninsula. As of the 2010 census, the city population was 7,708. It is the county seat of Houghton County...
, Hancock
Hancock, Michigan
Hancock is a city in Houghton County; the northernmost in the U.S. state of Michigan, located on the Keweenaw Peninsula, or, depending on terminology, Copper Island. The population was 4,634 at the 2010 census...
, and Calumet
Calumet, Michigan
Calumet is a village in Calumet Township, Houghton County, in the U.S. state of Michigan's Upper Peninsula, that was once at the center of the mining industry of the Upper Peninsula. Also known as Red Jacket, the village includes the Calumet Downtown Historic District, listed on the National...
.
In the early 20th century, copper companies began to consolidate. With very few exceptions, such as the Quincy Mine
Quincy Mine
The Quincy Mine is an extensive set of copper mines located near Hancock, Michigan. The mine was owned by the Quincy Mining Company and operated between 1846 and 1945, although some activities continued through the 1970s. The Quincy Mine was known as "Old Reliable," as the Quincy Mine Company paid...
at Hancock
Hancock, Michigan
Hancock is a city in Houghton County; the northernmost in the U.S. state of Michigan, located on the Keweenaw Peninsula, or, depending on terminology, Copper Island. The population was 4,634 at the 2010 census...
, the mines in the Copper Country came under the control of two companies: the Calumet and Hecla Mining Company
Calumet and Hecla Mining Company
The Calumet and Hecla Mining Company was a major copper-mining company based in the Michigan Copper Country. In the 19th century, the company paid out more than $72 million in shareholder dividends, more than any other mining company in the United States during that period.-History:In 1864, Edwin J...
north of Portage Lake, and Copper Range Company
Copper Range Company
The Copper Range Company was a major copper-mining company in the Copper Country of Michigan, United States. It began as the Copper Range Company in the late 19th century as a holding company specializing in shares in the copper mines south of Houghton, Michigan...
south of Portage Lake.
Annual production peaked in 1916 at 266 million pounds (121,000 metric tons) of copper. Most mines closed during the great depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
as a result of depressed copper prices. Many mines reopened during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, when wartime demand pushed copper prices higher. The end of the war brought an end to high prices, and nearly all companies closed, leaving only the Calumet and Hecla, Quincy, and Copper Range mining companies. Both Calumet and Hecla and Quincy survived largely by reprocessing the stamp sand
Stamp sand
Stamp sand is a coarse sand left over from the processing of ore in a stamp mill. In the United States, the most well-known deposits of stamp sand are in the Copper Country of northern Michigan, where it is black or dark grey, and may contain hazardous concentrations of trace metals.In the 19th...
left from older mining operations, leaching out copper left by more primitive processing techniques.
By 1968 the formerly great Calumet and Hecla was purchased by Universal Oil
UOP LLC
UOP LLC, formerly known as Universal Oil Products, is a multi-national company developing and delivering technology to the petroleum refining, gas processing, petrochemical production, and major manufacturing industries....
and became the company's Calumet division. By this time the Calumet and Hecla's original conglomerate workings had been abandoned and stamp sand reclamation had ended. The mines did not even produce enough copper to supply the company's internal demand. The company opened several new shafts and dewatered several old ones in hopes of finding additional wealth, but none were successful. Later that year, Calumet and Hecla's mine workers went out on strike, and the new owners closed the mines for good. Only the Copper Range company's White Pine mine remained open, and its ore was mostly copper sulfides, rather than native copper. Michigan's native copper industry was essentially dead, after producing 11 billion pounds (5.0 million metric tons) of copper.
Several companies attempted to reopen copper mines during the next two decades, including attempts by the Homestake Mining Company
Homestake Mining Company
The Homestake Mining Company was one of the largest gold mining businesses in the United States from the 19th century through the beginning of the 21st...
. None of these attempts lasted more than a couple of years or proved profitable.
Economic and environmental impact
The copper industry was, for over 100 years, the life blood of the Copper Country. The town of Red Jacket (now CalumetCalumet, Michigan
Calumet is a village in Calumet Township, Houghton County, in the U.S. state of Michigan's Upper Peninsula, that was once at the center of the mining industry of the Upper Peninsula. Also known as Red Jacket, the village includes the Calumet Downtown Historic District, listed on the National...
) used a portion of its budget surplus to build The Calumet Theatre
The Calumet Theatre
The Calumet Theatre is a historic theatre located at 340 Sixth Street in the town of Calumet, Michigan. It is also known as the Calumet Opera House or the Calumet Civic Auditorium. It is integral to, but a separate unit of, the Calumet municipal building...
, an opulent opera house which hosted famous plays and acts from across the world. Many wealthy mine managers built mansions which still line the streets of former mining towns. Some towns which existed primarily due to copper mining include Calumet, Houghton, Hancock, and Ontonagon. As the mines began to close, the Copper Country lost its major economic base. The population declined sharply as miners, shop owners, and others supported by the industry left the area, leaving many small ghost towns along the mineral range.
Tourism and logging are now the major industries. The copper industry left many abandoned mines and buildings across the Copper Country. Some of these are now part of the Keweenaw National Historical Park
Keweenaw National Historical Park
Keweenaw National Historical Park is a unit of the U.S. National Park Service. Established in 1992, the park celebrates the life and history of the Keweenaw Peninsula in the Upper Peninsula of the U.S. state of Michigan...
. Some mines, such as the Quincy Mine
Quincy Mine
The Quincy Mine is an extensive set of copper mines located near Hancock, Michigan. The mine was owned by the Quincy Mining Company and operated between 1846 and 1945, although some activities continued through the 1970s. The Quincy Mine was known as "Old Reliable," as the Quincy Mine Company paid...
and the Delaware Mine, are open as tourist attractions. Many other mining lands are simply left abandoned.
Copper mining also took a significant impact on the environment. Mine rock processing operations left many fields of stamp sand
Stamp sand
Stamp sand is a coarse sand left over from the processing of ore in a stamp mill. In the United States, the most well-known deposits of stamp sand are in the Copper Country of northern Michigan, where it is black or dark grey, and may contain hazardous concentrations of trace metals.In the 19th...
, some of which grew so large as to become hazards to navigation in the Keweenaw Waterway
Keweenaw Waterway
The Keweenaw Waterway is a partly natural, partly artificial waterway which cuts across the Keweenaw Peninsula of Michigan; it separates Copper Island from the mainland. Parts of the waterway are variously known as the Keweenaw Waterway, Portage Canal, Portage Lake Canal, Portage River, Lily Pond,...
. Most of these sterile sands are now superfund
Superfund
Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 , a United States federal law designed to clean up sites contaminated with hazardous substances...
sites which are slowly being rehabilitated. Mines also required a great deal of wood, largely for supports in mine tunnels. Virtually every part of the Copper Country was cleared of timber, to the extent that only one small area of old-growth forest (the Estivant Pines
Estivant Pines
Estivant Pines Nature Sanctuary is a nature sanctuary in Keweenaw County, Michigan. It is maintained and preserved by the Michigan Nature Association.- History :In the early 1970s logging began just south of what is now the sanctuary...
) is left. Formerly cleared lands have been left to regrow, to the extent that many parcels of land are now being harvested on a limited basis by timber and paper companies.
White Pine mine
The copper-bearing Nonesuch ShaleNonesuch Shale
The Nonesuch Shale is a Proterozoic geologic formation that outcrops in Michigan and Wisconsin, United States, but has been found by drill holes to extend in the subsurface as far southwest as Iowa....
at the south end of the Copper Country in 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...
had been known since the 1800s. But the ore grades were too low, the ore mineral particles too small, and the copper was largely in sulfides instead of native copper. All these conditions made the shale deposits uneconomical, although repeated attempts were made to mine the shale at the Nonesuch mine
Nonesuch Mine
The Nonesuch Mine is an abandoned copper mine and small ghost town in the southeast corner of the Porcupine Mountains State Park in Carp Lake Township, Ontonagon County, near Silver City, Michigan, United States. The area was given its name soon after Ed Less discovered the Nonesuch vein of copper...
.
In 1955 the Copper Range Company
Copper Range Company
The Copper Range Company was a major copper-mining company in the Copper Country of Michigan, United States. It began as the Copper Range Company in the late 19th century as a holding company specializing in shares in the copper mines south of Houghton, Michigan...
began large-scale mining at the White Pine mine, near the old Nonesuch mine. The deposit is a stratiform deposit in the lower 15 m of the Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
Nonesuch Shale
Nonesuch Shale
The Nonesuch Shale is a Proterozoic geologic formation that outcrops in Michigan and Wisconsin, United States, but has been found by drill holes to extend in the subsurface as far southwest as Iowa....
and the upper 2 m of the underlying Copper Harbor Conglomerate. The principal ore mineral was chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
, although native copper
Native 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...
predominated in the lower part of the beds. The mine was very successful, producing more than 1.8 million metric tons of copper during its life. The White Pine mine, the last major copper mine in Michigan, shut down in 1995.
The company applied to government agencies to continue mining by in-situ leaching, using sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
to recover an additional 900 million pounds of copper by SX-EW
SX-EW
Solvent extraction and electrowinning is a two-stage metallurgy process that first extracts and upgrades copper ions from low-grade leach solutions into a concentrated electrolyte , and then deposits pure copper onto cathodes using an electrolytic procedure ....
. The Michigan Department of Environmental Quality approved the permit in May 1996, and White Pine installed a pilot in-situ leaching project.http://www.deq.state.mi.us/pr/1996releases/960528.html Native Americans of the Bad River Indian Reservation in northern Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
blockaded rail shipments of sulfuric acid to the mine (see Bad River Train Blockade
Bad River Train Blockade
The Bad River train blockade was a 1996 protest on the Bad River Ojibwe Reservation in Ashland County, Wisconsin USA. Ojibwe activists blocked the railroad tracks that would have brought sulfuric acid to a mine in the Upper Peninsula of Michigan bringing national scrutiny on the United States...
); the mine began receiving acid shipments by truck. The U.S. Environmental Protection Agency (EPA), which had previously held that it had no role in the permitting, reversed itself, and stated that White Pine would have to apply for a federal permit. White Pine, which had already started to recover copper from the pilot project, suspended solution mining in October 1996, and applied for to the EPA for the permit.http://www.umich.edu/~snre492/pmaj.html In May 1997 the company withdrew the EPA permit application, saying that further permitting delays had made the project uneconomical, and announced plans to begin reclamation of the mine site.
The tailings impoundment at the White Pine Mine is presently the site of significant environmental degradation. The University of Montana undertook extensive efforts to restore and revegetate the barren landscape from 1997-1999, but it is unclear whether this has been successful. The university has published a detailed report of its project.http://ecorestoration.montana.edu/mineland/histories/metal/white_pine/default.htm Satellite images are available at (46°47′17.91"N 89°31′47.97"W).
Eagle project
Kennecott Eagle Minerals Corporation has proposed to open a nickelNickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
-copper
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 called the Eagle mine project
Eagle mine project
The Eagle mine project is a proposed nickel and copper mine by Kennecott Minerals Corporation, a subsidiary of Rio Tinto. The company is currently considering opening the mine on the Yellow Dog Plains in Michigan's Upper Peninsula . Nickel and copper are the principal metals to be mined, but...
in the Yellow Dog Plains
Yellow Dog Plains
The Yellow Dog Plains is an area north and west of Marquette, Michigan, in the Upper Peninsula of Michigan, United States. The Yellow Dog River flows through it, as does the Salmon Trout River. The Salmon Trout River is unique in that it has a breeding population of coasters, a potamodramous form...
, about 25 miles northwest of Marquette
Marquette, Michigan
Marquette is a city in the U.S. state of Michigan and the county seat of Marquette County. The population was 21,355 at the 2010 census, making it the most populated city of the Upper Peninsula. Marquette is a major port on Lake Superior, primarily for shipping iron ore and is the home of Northern...
, in 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"....
's Upper Peninsula. Construction work started in 2010, with production beginning at the end of 2013 and to continue up to 8 years. After mining is finished the site will be reclaimed. The mine will produce separate nickel and copper concentrates containing an average of 17,300 and 13,200 tonnes per year of nickel and copper respectively. Ores will be processed at the Humboldt Mill in Champion, Michigan for processing. The ore deposit is estimated to contain up to 140 thousand metric tons of nickel and 91 thousand metric tons of copper, as well as platinum, palladium, and cobalt.
See also
- Copper Country Strike of 1913-1914
- Italian Hall disasterItalian Hall disasterThe Italian Hall Disaster is a tragedy that occurred on December 24, 1913 in Calumet, Michigan...
- Keweenaw National Historical ParkKeweenaw National Historical ParkKeweenaw National Historical Park is a unit of the U.S. National Park Service. Established in 1992, the park celebrates the life and history of the Keweenaw Peninsula in the Upper Peninsula of the U.S. state of Michigan...
- List of Copper Country mines
- List of Copper Country mills
- List of Copper Country smelters
- Lists of copper mines in the United States