Copper mining in Michigan
In
Geology
Within the state of
The native copper deposits originate in fissures, steeply dipping veins or in the amygdaloid top portion of the Portage Lake Lava Series lava tops and conglomerate beds. This series of lava "is at least 15,000 feet thick in the Michigan copper district" and consists of "several hundred flood basalt flows." The district rocks are Precambrian in age and belong to the Keweenawan Series. The first six years of mining exploited the fissure deposits, then gave way to the amygdaloidal deposits.[1]: 306, 308
Although native copper was the dominant ore mineral,
Native American
Native Americans 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.[3] Some authors have suggested that as much as 1.5 billion pounds of copper was extracted during this period, but some archaeologists consider such high figures as "ill-constructed estimates" and that the actual figure is unknown. Archaeologist Susan Martin wrote that "“The competent excavation of many prehistoric archaeological sites in the Lake Superior basin reveals the continuous use of copper throughout the prehistoric time range, in association with all of the other items of material culture (projectile points, pottery and the like) that are without a doubt the products of native technologies. Many of these sites have been dated reliably by radiocarbon means.... Clearly, copper-working continues up until the years of aboriginal contact with seventeenth-century Europeans. The speculators could at least acknowledge these facts rather than pretend that the association of copper with indigenous people doesn’t exist.” [4]
By the time the first European explorers arrived, the area was the home of the
Douglass Houghton's 1841 copper report, followed by the Treaty of La Pointe in 1843, the publicity of the Ontonagon Boulder back east, and a federal mineral land office at Copper Harbor kicked off the mine rush.[6]
The copper pits abandoned by Native Americans led early miners to most of the first successful mines. "All the principal ore deposits were thus known before 1900, and each was discovered in exposures at or close to grass roots."[1]: 306
Modern mining industry
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.[1][6]: 16–17 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.[7] 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.[8]
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 mine, began operations in 1845, and many others quickly followed. These first mines worked copper-filled fissure veins that cut across stratigraphic layers.[1]: 306
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 Ontonagon 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."
Stratiform deposits
Copper mining in MichiganIn the 1850s, mining began on stratiform native copper deposits in felsite-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 stratiform 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. "Large scale production ceased in 1939."[1]: 306
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 (3.2 km) wide and 24 miles (39 km) 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
Annual production peaked in 1916 at 266 million pounds (121,000 metric tons) of copper. Most mines closed during the
By 1968 the formerly great Calumet and Hecla was purchased by
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.
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
Tourism, education, 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
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, for supports in mine tunnels, housing, and steam generation. Virtually every part of the Copper Country was cleared of timber, to the extent that only a few small areas of old-growth forest like (the Estivant Pines) are 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 Shale 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 (4.0 billion pounds) of copper during its life.[citation needed] The White Pine mine, the last major copper mine in Michigan, shut down in 1995.[12]
The company applied to government agencies to continue mining by
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 to 1999, but it is unclear whether this has been successful. The university has published a detailed report of its project.[15] Satellite images are available at (46°47′17.91″N 89°31′47.97″W / 46.7883083°N 89.5299917°W).
In 2012, SubTerra used the mine for pharmaceutical research.[16]
The July 7th 2021 edition of the local news outlet Keweenaw Report has the headline: Mining set to return to White Pine.[17]
Eagle Mine
In addition to sedimentary copper ores that dominate the Upper Peninsula, Eagle Mine is a high-grade magmatic nickel-copper (Ni-Cu) sulfide-bearing deposit discovered by Rio Tinto in 2002 and later sold to Lundin Mining (2013).
Eagle Mine was the first operation to be permitted under Michigan's Non-Ferrous Metallic Mining Law, better known as Part 632.
Copperwood Mine
On March 13, 2013, the Michigan Department of Environmental Quality (DEQ) issued Orvana Corporation, of Toronto, Ont. final permits to begin mining north of Wakefield, in Gogebic County.[19]
Orvana estimates that approximately one billion pounds of copper are present at their site, along with smaller quantities of silver. Studies indicate that 800 million pounds (360,000 metric tons) of copper can be extracted, as well as 3,456,000 ounces of silver. Production would last 13 years, based on those reserves.[20] The project was then bought by Highland Copper Company, a Montreal-based exploration company in 2014 and an updated feasibility report is underway and permits for the project are forthcoming by the end of 2018.
Back Forty Mine
The Back Forty Mine is a proposed
See also
- Minong Mine Historic District
- Copper Country Strike of 1913-1914
- Italian Hall disaster
- Keweenaw National Historical Park
- List of Copper Country mines
- List of Copper Country mills
- List of Copper Country smelters
- Lists of copper mines in the United States
- Quincy and Torch Lake Cog Railway
- Fort Wilkins Historic State Park
References
- ^ a b c d e White, Walter S. (1968). "The Native-Copper Deposits of Northern Michigan". Ore Deposits of the United States, 1933–1967. Vol. 1. New York: American Institute of Mining Engineers. pp. 303–325.
- ^ "Halfbreed: Halfbreed mineral information and data". Mindat.org. Hudson Institute of Mineralogy.
- ISBN 0472064479 – via Google Books.
- ^ Martin, Susan R. (1995). "The State of Our Knowledge About Ancient Copper Mining in Michigan". The Michigan Archaeologist. 41 (2–3): 119–138. Archived from the original on February 7, 2016. Retrieved August 31, 2017.
- ^ Mulholland, James A. (1981). A History of Metals in Colonial America. University: University of Alabama Press. pp. 41–42.
- ^ ISBN 9780814334904.
- ^ Crane, W.R. (1929). Mining Methods and Practice in the Michigan Copper Mines. United States Bureau of Mines. p. 3. Bulletin 306.
- ^ Stevens, Horace J. (1909). The Copper Handbook. Vol. 8. Houghton, MI: Horace Stevens. p. 1466.
- Michigan Department of Environmental Quality. pp. 136–137.
- ^ Thurner, Arthur W. (1994). Strangers and Sojurners: A History of Michigan's Keweenaw Peninsula. Detroit: Wayne State University Press. p. 286.
- .
- ^ Binder, David (September 14, 1995). "Upper Peninsula Journal; Yes, They're Yoopers, and Proud of It". The New York Times.
- ^ Silfven, Ken; Johnson, Robin (May 28, 1996). "DEQ Press Release" (Press release). Archived from the original on September 29, 2007. Retrieved August 6, 2007.
- ^ "Environmental Justice Case Study: Solution Mining in White Pine, MI and the Bad River Reservation". SNRE 492 Course Section of the Environmental Justice Institute. University of Michigan School of Natural Resources and Environment.
- ^ Williams, Tom (August 2004). "White Pine Mine". Ecosystem Restoration. Archived from the original on December 12, 2012. Retrieved August 28, 2007.
- ^ Egan, Paul (April 22, 2012). "Company Wants to Grow Quality Medical Marijuana in Old Mine". Detroit Free Press. Retrieved April 24, 2012.
- ^ "Mining set to return to White Pine". keweenawreport.com. Keweenaw Report. July 7, 2021. Retrieved July 9, 2021.
- ^ "Eagle". Lundin Mining Corporation. Retrieved May 15, 2019.
- ^ Casey, Steve; Wurfel, Brad (March 19, 2013). "Permit Signed for Copperwood Mine Project" (Press release). Michigan Department of Environmental Quality. 13-319. Archived from the original on April 3, 2013.
- ^ Keane, Joseph M.; Milne, Steve; Kerr, Thomas (March 21, 2012). Feasibility Study of the Copperwood Project, Upper Peninsula, Michigan, USA (PDF). Tucson, AZ: K D Engineering. Q431-01-028. Archived from the original (PDF) on December 3, 2013. Retrieved November 17, 2013.
Further reading
- Pelto, Brendan (2017). Black-Americans in Michigan's Copper Mining Narrative (Thesis). Michigan Technological University. .
External links
- Adventure Mining Company
- Delaware mine
- Quincy Mine Hoist Association
- Mine Site Visit: Copper Range Company White Pine Mine. U.S. Environmental Protection Agency, Office of Solid Waste, observations from EPA site visit May 5 and 6, 1992