Geology and History
of the Mesabi Iron Range
A geologic mapper’s perspective
Mark Jirsa
Minnesota Geological Survey
University of Minnesota
St. Paul
Leith, 1911
MESABI MILESTONES
A chronology of historical events
affecting the Mesabi Iron Range
1500's—Iron oxide and fish oil were combined to make paint for native pictographs.
1843—Nicollet explores--uses Indian name Missabay or "Giant Hills", later changed to Mesabi.
1844—Douglas Houghton and surveyor William Burt notice compass deflection near Escanaba, MI. and discovers iron at Negaunee, Marquette range, MI.
1846—Marquette range (MI)—ships iron ore.
1847-1852—Land Survey of Minnesota Territories by US government.
1848—First "iron blooms" were hammered out in Escanaba MI.
1849—Minnesota Territory established.
1850—Gunflint range (MN)—iron discovered by J.G. Norwood.
1851—Dale Owen publishes “Geologic map of Wisconsin, Iowa and Minnesota (U.S. Treasury Department)
1855—St. Mary's canal opened at Sault Ste Marie, first steamer through locks. Allows shipping out of Lake Superior into the other Great Lakes.
1856—Henry Bessemer (London) developed a furnace that injects air and heats so hot as to remove silica and carbon impurities in iron ore.
Makes first steel from pig or wrought iron.
1857—Depression ("a corner lot in Duluth is not worth a pair of boots!").
1858—Minnesota statehood.
1865—George Stuntz (government surveyor) discovered iron ore at Lake Vermilion.
1865—Lake Vermilion—Henry H. Eames and brother Robert collected iron ore and gold-quartz samples.
1866—Lake Vermilion—Governor Miller involved with Eames in gold claims, acquired “Indian script” lands.
1872—Minnesota Geological and and Natural History Survey established
1872—N.H. Winchell, as director, published “Preliminary Geologic Map of Minnesota”
1873—Depression.
1875—Professor A.H. Chester surveyed and analyzed Mesabi iron-formation.
1877—Menominee range (MI) shipped iron ore.
1882—Vermilion range (MN)—iron mining began (involving Stuntz, Stone, and Tower).
1882—Colby Mine opened—the first on Gogebic range (MI).
1884—Gogebic range (MI)—shipped first iron ore.
1884—Vermilion—railroad completed (by Charlemain Tower) from Two Harbors
(Agate Bay) to Tower (later connected from Two Harbors to Duluth).
1884—Vermilion range—first iron ore shipped (Breitung mine, near Soudan).
1885 Soudan Mine opened.
1888 Chandler and South Chandler mines at Ely opened.
1889 Savoy and Pioneer Mines near Ely opened.
1884—Newton Winchell (geologist-Minnesota Geological and Natural History Survey) traveled to New Orleans World's Fair with a large exhibit of Minnesota rocks and minerals including catlinite,
building stones, hematite (natural iron ore), and sodium chloride (salt extracted from well at Humboldt in Kittson County).
1887—Law passed by Minnesota Legislature requiring "the state geologist to make special examinations for the discovery of any economic product which he might have reason to believe existed at
any place in the rocks of the state and report thereon for the information of the citizens of the state."
1890—Edmund J. Longyear sank the first diamond drill hole (near Hoyt Lakes, Mesabi range, MN).
1891-1892—John McCaskill noticed soft ore clinging to tree roots near present Biwabik and sank 65 test pits, all assayed at greater than 65% iron.
1892—Mesabi range—first iron ore shipment (Merritt brothers) from Mountain Iron.
1892—Frank Hibbing discovered iron ore west of Virginia.
1892—McDougal's Whaleback ore carrier transported the Merritts first ore from Mountain Iron Mine.
1893—David Adams published first geologic map of Mesabi range based on field observations.
1893—Depression—many unemployed as iron drops from $2.46 to $1.55/ton. “Big money” bail-outs from names like Rockefeller and Carnegie.
1900—N.H. Winchell, published Geologic Map of Minnesta, assigns iron-formation Taconic for Cambrian formations in New York (“taconyte”); then resigns MGNHS
1901—Van Hise and Leith named the iron-bearing formations on the Mesabi range "Biwabik" Iron Formation (Biwbik is a Chippewa Indian word for “piece of iron”).
1901—J.P. Morgan formed US Steel Corporation, merging the holdings of Henry Oliver, John Rockefeller and Andrew Carnegie.
1904—Cuyler Adams (with his dog "Una") test drilled iron ore near Deerwood in east-central MN, in what became known as the Cuyuna range.
1907—Labor strike on the Mesabi range for 8 hour days and wages from $1.50 to $2.00/day.
1907-08—Depression—many mines closed forever.
1911—Cuyuna range—shipped iron ore from the Kennedy Mine near Rabbit Lake.
1911—C.K. Leith publishes map of Mesabi Range in USGS Monograph with Van Hise onGeology of the Lake Superior region
1917—U.S. entered WW I.
1922-24—Experimental taconite plant operated.
1929—Stock market crashed and economic depression began.
1932—Frank Grout (MGS) and others published “Geologic Map of the state of Minnesota,”
1941—U.S. entered WW II, following attack on Pearl Harbor.
1953—Largest annual iron ore shipment from Mesabi range of 75,953,215 tons (~76 million tons).
1953—Mesabi range—taconite process developed by Davis, and a pilot plant began at Mountain Iron.
1955—Taconite mining and production successfully begun by Erie Mining and Reserve Mining.
1962—Vermilion range—Soudan Mine closed.
1963—Soudan Mine opens as a state park
1964—Taconite Amendment calls for no tax increases for 10 years, and the mining picture improves.
1967—Vermilion range—Pioneer Mine (Ely trough) ceases operation, the last of that range.
1969—Mine Land Reclamation Law passed by state legislature.
1973—Ironworld (Iron Range Interpretative Center) opened in Chisholm, near abandoned Glen Mine.
1978—Cuyuna range—last mines closed. The Algoma and Zeno Mines continued shipping from stockpiles through 1984.
1988—Hill Annex Mine (Mesabi) begins operating as a state park.
Photo source: Iron Range Research
1992—U.S. Bureau of Mines experiments with extraction of manganese from Algoma and Zeno ores on the Cuyuna range.
Center, Chisholm MN
OUTLINE
1. Primer on geologic map-making
2. Iron range history as depicted on maps
3. Highlights of “Mesabi Milestones” chronology
4. Origin and demise of iron-formation
5. Future of the Mesabi Iron Range
BEDROCK GEOLOGIC
FRAMEWORK
QUATERNARY GLACIAL SEDIMENTS
~2 Ma-12 ka
Keewatin
center
Labrador
center
DEPTH TO BEDROCK 2010
0 Feet
800 Feet
SOURCES OF MAPPING DATA
MGS well records
Outcrop
DIGITIZED LAND SURFACE TOPOGRAPHY and LIDAR
Light Detection And Ranging
Magnetic
Surveying
Gravity
(density)
Surveying
MINNESOTA IRON RANGES
GUNFLINT
VERMILION
MESABI
CUYUNA
Winchell, 1872
Owen, 1851
Winchell, 1900
Sims, 1970
Grout, 1932
Morey, 1976
MESABI MILESTONES
WHAT YOU NEED TO KNOW ABOUT
MESABI RANGE HISTORY, FOR NOW…
1865—Henry H. Eames (State Geologist) canoed St Louis River and Embarrass Lake and reported
“immense bodies of the ores of iron;” and ascended the Prairie River, reporting similar finds.
In one year, he unknowingly defined the eastern and western ends of the Mesabi Iron Range.
1890—Merritt brothers discovered iron ore
near Mountain Iron.
1892—First MESABI iron ore shipped
from Mountain Iron.
Dale Owen, 1851
(funded by U.S. Treasury Department)
N.H. Winchell, 1872 (Minnesota Geological and Natural History Survey)
N.H. Winchell, 1900
C.R. Van Hise and C.K. Leith, 1911
USGS Monograph
F.F. Grout and others, 1932 (MGS)
Objective: A new geologic map of the Mesabi Iron Range
BEDROCK GEOLOGIC MAP
MGS M-163; Jirsa, Chandler, and Lively, 2005
Biwabik Iron Formation
(~1.8 Ga)
Wawa subprovince
(~2.7 Ga)
Babbitt
MESOPROTEROZOIC
Virginia
ARCHEAN
Hibbing
Biwabik
PALEOPROTEROZOIC
Duluth Complex
(~1.1 Ga)
Grand
Rapids
Virginia FormationThomson Fm. at
Jay Cooke State Park
(~1.8-1.7 Ga)
GEOLOGIC MAPPING
using GIS-INTEGRATED DATA
Quads are useless in
this land of ever-changing
topography
1) Air photography
2) Archived geologic maps
3) Outcrop, test pit and drill hole data
4) Digital bedrock topography
5) Geophysical maps and data
6) Field observations
“PRE-MINING”
LAND SURFACE
TOPOGRAPHY
• 1:16,000-scale topographic mapping--circa 1899.
• Depicts pre-mining landforms and drainage.
• Contains hand-drawn geologic, test-pit, and drill hole information.
• Digitized to estimate archived DH drill collars, quantify land
surface changes over 100 years of mining, and preserve geologic
data.
1899 MAP
Land surface topography by U.S. Geological Survey
Geologic notes by John Uno Sebenius, circa 1900
Inferred geologic
contact
Test Pits
*Two of the many pieces, skillfully re-rendered and digitized by Emily Bauer, MGS
Longyear, 1951
Longevity and productivity: 400 Separately named mines, >120 years
Digital Elevation Model Central Mesabi Iron Range DNR, 1999
CONTRASTS IN LAND-SURFACE TOPOGRAPHY,
INFRASTRUCTURE, AND SURFACE HYDROLOGY
Useful for issues of
mine reclamation and
watershed restoration
1899
1999
Keewatin
Taconite
Hibbing
Taconite
Modified from Lively, Morey, and Bauer, 2002; MGS M-118
CHANGE IN LAND SURFACE
TOPOGRAPHY
“Mounds”
+240 feet
1899-1999
Hibbing Area
“Mines”
0 feet
-340 feet
Lively and others, 2002 estimate ~45% of the 1899 map area was modified by mining.
STRUCTURAL MAPPING
Blast deformation (“fluff”)
@ Hibbing Taconite Mine
FOLDS
FAULTS
JOINTS
Conjugate faults @ Susquehanna Mine
• Create bedrock geologic map
• Understand deformation history
• Evaluate role as hydrologic conduits
Joints @ Chisholm Mine
CONTRASTS in 100 years of geologic understanding…
1903 Leith map
Babbitt
Virginia
Hibbing
Grand Rapids
2005 MGS map (M-163)
CONTRASTS
in detail…
1911 Leith map
2005 MGS map
MESABI MILESTONES
1500's—Iron oxide and fish oil were combined to make paint for native pictographs.
1843—Nicollet explores--uses Indian name Missabay or "Giant Hills", later changed to Mesabi.
1844—Douglas Houghton and surveyor William Burt notice compass deflection near Escanaba, MI. and discovers iron at Negaunee, Marquette range, MI.
1846—Marquette range (MI)—ships iron ore.
1847-1852—Land Survey of Minnesota Territories by US government.
1848—First "iron blooms" were hammered out in Escanaba MI.
1849—Minnesota Territory established.
1850—Gunflint range (MN)—iron discovered by J.G. Norwood.
1851—Dale Owen publishes “Geologic map of Wisconsin, Iowa and Minnesota (U.S. Treasury Department)
1855—St. Mary's canal opened at Sault Ste Marie, first steamer through locks. Allows shipping out of Lake Superior into the other Great Lakes.
1856—Henry Bessemer (London) developed a furnace that injects air and heats so hot as to remove silica and carbon impurities in iron ore.
Makes first steel from pig or wrought iron.
1857—Depression ("a corner lot in Duluth is not worth a pair of boots!").
1858—Minnesota statehood.
1865—George Stuntz (government surveyor) discovered iron ore at Lake Vermilion.
1865—Lake Vermilion—Henry H. Eames and brother Robert collected iron ore and gold-quartz samples.
1866—Lake Vermilion—Governor Miller involved with Eames in gold claims, acquired “Indian script” lands.
1872—Minnesota Geological and and Natural History Survey established
1872—N.H. Winchell, as director, published “Preliminary Geologic Map of Minnesota”
1873—Depression.
1875—Professor A.H. Chester surveyed and analyzed Mesabi iron-formation.
1877—Menominee range (MI) shipped iron ore.
1882—Vermilion range (MN)—iron mining began (involving Stuntz, Stone, and Tower).
1882—Colby Mine opened—the first on Gogebic range (MI).
1884—Gogebic range (MI)—shipped first iron ore.
1884—Vermilion—railroad completed (by Charlemain Tower) from Two Harbors
(Agate Bay) to Tower (later connected from Two Harbors to Duluth).
1884—Vermilion range—first iron ore shipped (Breitung mine, near Soudan).
1885 Soudan Mine opened.
1888 Chandler and South Chandler mines at Ely opened.
1889 Savoy and Pioneer Mines near Ely opened.
1884—Newton Winchell (geologist-Minnesota Geological and Natural History Survey) traveled to New Orleans World's Fair with a large exhibit of Minnesota rocks and minerals including catlinite,
building stones, hematite (natural iron ore), and sodium chloride (salt extracted from well at Humboldt in Kittson County).
1887—Law passed by Minnesota Legislature requiring "the state geologist to make special examinations for the discovery of any economic product which he might have reason to believe existed at
any place in the rocks of the state and report thereon for the information of the citizens of the state."
1890—Edmund J. Longyear sank the first diamond drill hole (near Hoyt Lakes, Mesabi range, MN).
1891-1892—John McCaskill noticed soft ore clinging to tree roots near present Biwabik and sank 65 test pits, all assayed at greater than 65% iron.
1892—Mesabi range—first iron ore shipment (Merritt brothers) from Mountain Iron.
1892—Frank Hibbing discovered iron ore west of Virginia.
1892—McDougal's Whaleback ore carrier transported the Merritts first ore from Mountain Iron Mine.
1893—David Adams published first geologic map of Mesabi range based on field observations.
1893—Depression—many unemployed as iron drops from $2.46 to $1.55/ton. “Big money” bail-outs from names like Rockefeller and Carnegie.
1900—N.H. Winchell, published Geologic Map of Minnesta, assigns iron-formation Taconic for Cambrian formations in New York (“taconyte”); then resigns MGNHS
1901—Van Hise and Leith named the iron-bearing formations on the Mesabi range "Biwabik" Iron Formation (Biwbik is a Chippewa Indian word for “piece of iron”).
1901—J.P. Morgan formed US Steel Corporation, merging the holdings of Henry Oliver, John Rockefeller and Andrew Carnegie.
1904—Cuyler Adams (with his dog "Una") test drilled iron ore near Deerwood in east-central MN, in what became known as the Cuyuna range.
1907—Labor strike on the Mesabi range for 8 hour days and wages from $1.50 to $2.00/day.
1907-08—Depression—many mines closed forever.
1911—Cuyuna range—shipped iron ore from the Kennedy Mine near Rabbit Lake.
1911—C.K. Leith publishes map of Mesabi Range in USGS Monograph with Van Hise onGeology of the Lake Superior region
1917—U.S. entered WW I.
1922-24—Experimental taconite plant operated.
1929—Stock market crashed and economic depression began.
1932—Frank Grout (MGS) and others published “Geologic Map of the state of Minnesota,”
1941—U.S. entered WW II, following attack on Pearl Harbor.
1953—Largest annual iron ore shipment from Mesabi range of 75,953,215 tons (~76 million tons).
1953—Mesabi range—taconite process developed by Davis, and a pilot plant began at Mountain Iron.
1955—Taconite mining and production successfully begun by Erie Mining and Reserve Mining.
1962—Vermilion range—Soudan Mine closed.
1963—Soudan Mine opens as a state park
1964—Taconite Amendment calls for no tax increases for 10 years, and the mining picture improves.
1967—Vermilion range—Pioneer Mine (Ely trough) ceases operation, the last of that range.
1969—Mine Land Reclamation Law passed by state legislature.
1973—Ironworld (Iron Range Interpretative Center) opened in Chisholm, near abandoned Glen Mine.
1978—Cuyuna range—last mines closed. The Algoma and Zeno Mines continued shipping from stockpiles through 1984.
1988—Hill Annex Mine (Mesabi) begins operating as a state park.
1992—U.S. Bureau of Mines experiments with extraction of manganese from Algoma and Zeno ores on the Cuyuna range.
1994—Cuyuna Country Recreation Area created by state legislature.
2006—MGS publishes Bedrock and Quaternary Geologic Maps of Mesabi Iron Range
MESABI MILESTONES
~1500’s—Iron oxide + fish oil = pictograph paint
Hegman Lake
BWCAW
Lac la Croix
QUETICO
MESABI MILESTONES
1842—Ojibwe ceded title to many mineral lands in Wisconsin, Minnesota and Michigan
1843—Joseph Nicollet map—
uses Indian name Missabay
or "Giant Hills",
later changed to Mesabi.
Pipestone National Monument (NPS photo)
J.N. Nicollet, J.N., 1843, Hydrographical Basin
of the Upper Mississippi River
MESABI MILESTONES
1844—Douglas Houghton and surveyor William Burt notice compass deflection near Escanaba, MI.
and discover iron at Negaunee, Marquette range, MI.
1846—Marquette range (MI)—ships iron ore.
1847-1852—First Land Survey of Minnesota Territories by US government.
1848—First "iron blooms" were hammered out in Escanaba MI.
1849—Minnesota Territory established.
1850—Gunflint range (MN)—iron discovered by J.G. Norwood.
THUNDER
BAY
MESABI
GUNFLINT
Pye and Fenwick, 1964
GUNFLINT IRON RANGE 1888-1893
1850—Discovery
1888—Underground Paulson Mine opened
(3 shafts).
1893—Depression/Panic; mine closed.
One car-load of “hand-cobbed”
magnetite ore was shipped 1893
via new rail line to Thunder Bay (red).
Paulson Mine
Grout, 1929
MESABI MILESTONES
1851—Dale Owen published “Geologic map of Wisconsin, Iowa and Minnesota
1855—St. Mary's canal opened at Sault Ste Marie, first steamer through locks.
1856—Henry Bessemer (London) developed a furnace that injects air and heats so hot as to
remove silica and carbon impurities in iron ore. Makes first steel from pig or wrought iron.
1857—Depression ("a corner lot in Duluth is not worth a pair of boots!").
1858—Minnesota statehood.
1865—Henry H. Eames (State Geologist) defined the eastern and
western ends of the Mesabi Iron Range. AND…
WINCHELL, 1872
LAKE VERMILION
GOLD RUSH
1865-1867
In search of rumored
iron deposits,
Henry Eames
reports finding GOLD
Quartz veins
Agents acting on behalf of
Governor Miller and Eames
form MINNESOTA GOLD
MINING COMPANY
They quietly filed claims
using so-called
“Half-breed script”
Then released inflated reports of gold assays
and sold the claims at great profit.
Photo source: Iron Range Research Center, Chisholm MN
NO MINES EVER OPERATED!
MESABI MILESTONES
1865—George Stuntz (government surveyor in search of GOLD)
discovered iron ore at Lake Vermilion.
1872—Minnesota Geological and Natural History Survey established (U of M)
1872—N.H. Winchell, as director, published “Preliminary Geologic Map of Minnesota”
1873—Depression.
1875—U of M Professor A.H. Chester surveyed and analyzed Mesabi iron-formation.
Land Surveys 1848-1890
Surveyors notes include mentions of minerals
(noteably those of George Stuntz, 1865)
Survey lines locally deflected
Lake Vermilion area
Photo source: Roots magazine,
Minnesota Boundaries, 1978
VERMILION IRON RANGE
Operation: 1884-1962
Ely
Tower
“Blue” hematite ore
ORE discovered in 1865, blasting began in 1875
It was not until completion of Tower’s rail
line to Two Harbors in 1884 that the
first ore was shipped.
Photo source: Iron Range Research Center, Chisholm MN
MESABI MILESTONES
1882—Vermilion range (MN)—iron mining began (involving Stuntz, Stone, and Tower).
1882—Colby Mine opened—the first on Gogebic range (MI).
1881-82—Alexander McDougall patented steel lake freighters known as “Whalebacks”
1884—Gogebic range (MI)—shipped first iron ore.
1884—Vermilion—railroad completed (by Charlemain Tower) from Two Harbors
(Agate Bay) to Tower (later connected from Two Harbors to Duluth).
1884—Vermilion range—first iron ore shipped (Breitung mine, near Soudan).
1885 Soudan Mine opened.
1888 Chandler and South Chandler mines at Ely opened.
1889 Savoy and Pioneer Mines near Ely opened.
Steeply dipping ore deposits required deep (>2400’) underground mining.
There was little need for the constant moving of structures that plagued
later iron mining communities. Many old structures remain.
In contrast to the earlier gold rush nearby,
the Vermilion "iron rush" was long-lived…
1884-1962
Photo source: Iron Range Research Center, Chisholm MN
MESABI MILESTONES
1890—Edmund J. Longyear sank the first diamond drill hole (near Hoyt Lakes, Mesabi range, MN).
1890—Merritt brothers discovered iron ore near Mountain Iron.
1891-1892—John McCaskill noticed soft ore clinging to tree roots near present Biwabik
and sank 65 test pits, all assayed at greater than 65% iron.
1892—MESABI RANGE—first iron ore shipped from Mountain Iron (on McDougall’s whaleback)
1892—Frank Hibbing discovered iron ore west of Virginia.
1893—Depression—many unemployed as iron drops from $2.46 to $1.55/ton.
“Big money” bail-outs came from names like Rockefeller and Carnegie.
1900—N.H. Winchell, published Geologic Map of Minnesota, assigned iron-formation
Taconic for Cambrian formations in New York (“taconyte”); then resigns MGNHS
Hoyt Lakes
MOUNTAIN IRON
Hibbing
Biwabik
MESABI IRON RANGE
1892-present
SKEPTICS said the Mesabi
would never be mined…
MESABI IRON RANGE
Rocks of the Mesabi Range didn’t fit
the Vermilion EXPLORATION MODEL:
MESABI
VERMILION
Flat-lying
Steep
Deep red
Steel blue ore
Soft ores
Hard ores
Wet
Dry
Vermilion Iron Range
First mine 1892 at Mountain Iron
in oxidized “natural ore”
Photo source: Iron Range Research Center, Chisholm MN
(17-30% Fe, 50% SiO2)
MAGNETIC
(>50% Fe, <10% SiO2)
NONMAGNETIC
Dip Needle
FORMATION OF NATURAL ORES BY OXIDATION, LEACHING, WEATHERING
Cloquet Mine (NS)
m205b Leonidas Mine
Protolith (Taconite)
Mountain Iron Mine
Deeply weathered
@ Canisteo Mine
BEDROCK GEOLOGY DRAPED ON
PRE-MINING BEDROCK TOPOGRAPHY
West Mesabi
Iron Range
Linear depressions on
bedrock surface
inferred to be faults
Hibbing Area
LINEAMENTS
Bedrock topographic low
Magnetic low
Magnetic high
Mapped fault
Mine trend
Glen Mine
Aeromagnetic map
UNDERGROUND
MINING
Original 3D image from
Minnesota Department of Natural Resources
Study of U/G Mining, Central Mesabi range, ~2008
Glen Mine
UG~1902
MESABI MILESTONES
1901—Van Hise and Leith named the iron-bearing formations on the Mesabi range
"Biwabik" Iron Formation (Biwabik is a Chippewa Indian word for “piece of iron”).
1901—J.P. Morgan formed US Steel Corporation, merging the holdings of Henry Oliver,
John Rockefeller and Andrew Carnegie.
1904—Cuyler Adams test drilled iron ore near Deerwood in east-central MN,
1907—Labor strike on the Mesabi range for 8 hour days and wages from $1.50 to $2.00/day.
1907-08—Depression—many mines closed forever.
1911—C.K. Leith publishes map of Mesabi Range in USGS Monograph, with Van Hise
1911—CUYUNA RANGE—shipped first iron ore from the Kennedy Mine.
MESABI MILESTONES
1922-24—Experimental taconite plant operated.
1929—Stock market crashed and economic depression began.
1932—Frank Grout (MGS) and others published “Geologic Map of the state of Minnesota,”
1941—U.S. entered WW II, following attack on Pearl Harbor.
1953—Largest annual iron ore shipment from Mesabi range of 75,953,215 tons (~76 million tons).
1953—Taconite Process developed by E.W. Davis (University of Minnesota)
1955—Taconite mining and production successfully begun by Erie and Reserve Mining
Fused taconite pellets
“Taconite” ore
FACTORS THAT INFLUENCE WHAT MATERIALS
ARE VALUABLE ENOUGH TO BE CONSIDERED ORE:
 Demand/Supply=PRICE
- War/industrial expansion
- Exhaustion of reserves
- New discoveries
- Competition
 Technological changes=COSTS
- Mining methods
- Processing methods
- Transportation methods
Photo source: Iron Range Research Center, Chisholm MN
Image: Sandler, 1995, Immigrants;
Library of Congress
“ORE” is a moving target…
Oxidation and
natural ore mines
along faults and
folds
Virginia
Virginia
Narrow, steep-walled
mines.
Towns and
“locations” were built
close to the mines.
Photo source: Iron Range Research Center, Chisholm MN
Where prior ores contained ~ 60% iron,
“taconite” rock with as little as 17% iron could
now be considered ore.
RESULT:
More of the range,
and different parts
of the range
become “ore lands.”
Some towns were
destroyed,
others moved.
Photo source: Iron Range Research Center, Chisholm MN
S
Taconite Mining in the 1950’s
A shift in the “ore of choice”
Taconite
Hibbing Taconite mines
S
Photo by David A. Witt, P.G., Aero-Environmental Consulting 2005
HIBBING TACONITE
Susquehanna-Mahoning
natural ore mine
“Fissure ore body”
Mined channels @ N75W + N20W
Overlook
Oxidized (“natural ore”)
vs. magnetic (“taconite”)
iron-formation
Hibbing
Aeromagnetic map (white=magnetic)
STRUCTURE EXAMPLES FROM HIBTAC
Susquehanna fault/collapse
(m172c) L=SSE
HIBTAC mine
(m163b)
L=NE
Overlook
Scranton monocline
(m167a) L=SW
Lamberton Fault
(HT10) L=SE
South Agnew
fault and Quaternary
channel (m186b) L=SE
Susquehanna
fault w/ hematite
(m173c)
ORIGIN and DEMISE
of IRON-FORMATION
Lake Superior-type iron “ranges”
All about the same age…
Thunder Bay
Gunflint
Mesabi
Duluth
Emily
Cuyuna
Gogebic
Marquette
Iron River-Crystal Falls,
Felch, Menominee
Google Earth 2008
Iron-formation
ANIMIKIE BASIN
PENOKEAN OROGEN
Iron-formation
Image source: J.D. Miller, unpublished
Image source: J.D. Miller, unpublished
MESABI and GUNFLINT IRON RANGES
(Image of J.D. Miller, Jr., unpublished)
STROMATOLITES:
Fossil evidence of Cyanobacteria
Modern microbialite; lagoon in Australia (R. Shapiro)
Imagery: Russell Shapiro
GENERALIZED STRATIGRAPHY
Showing mined taconite intervals and locations
(Modified from Jirsa , Miller, and Morey, 2008 after a compilation by Henry Djerlev, 1993)
Limitations of Scale
Stratigraphy and depositional model by Mark Severson, NRRI-U of M, 2010
“SLATY”
“CHERTY”
“SLATY”
“CHERTY”
“SLATY”
MINING COMPANY GEOLOGIC MAPS
Former LTV
Mines
TACONITE
MINES
VIRGINIA FORMATION
DULUTH COMPLEX
Taconite (gray shaded) mined from several intervals
MESABI MILESTONES
1962—Vermilion range—Soudan Mine closed.
1963—Soudan Mine opened as a state park
1964—Taconite Amendment called for no tax increases for 10 years, and the mining picture improved.
1967—Vermilion range—Pioneer Mine (Ely trough) ceased operation, the last of that range.
1969—Mine Land Reclamation Law passed by state legislature.
1978—Cuyuna range—last mines closed.
The Algoma and Zeno Mines continued shipping from stockpiles through 1984.
1988—Hill Annex Mine (Mesabi) began operating as a state park.
1992—U.S. Bureau of Mines experimented with extraction of manganese from
Algoma and Zeno ores on the Cuyuna range.
2005--Discovery by Addison and others of
ejecta blanket from 1850 Ma Sudbury
meteorite impact at the stratigraphic top
of iron-formation
SUDBURY METEORITE IMPACT EVENT
Of 183 confirmed
structures:*
Lake Superior
3rd largest
4th oldest
~130 km (80 miles)
Googlearth
BY CRATER SIZE
1. Vredefort (S. Africa) 160 km
2. Chicxulub (Mexico) 150 km
3. Sudbury (Ontario) 130 km
*Earth Impact Database, 2011.
<http://www.unb.ca/passc/ImpactDatabase/>
(Accessed: Dec., 2012)
BY AGE
1. Suarjarvi (Finland)
~2400 Ma
2. Vredefort (S. Africa)
2023 Ma
3. Yarrabubba (Australia) ~2000 Ma
4. Sudbury (Ontario)
1850 Ma
117. Chicxulub (Mexico) 65 Ma
The “DEMISE” of Lake Superior-type iron-formations
SUDBURY IMPACT
Thunder Bay
Gunflint
1850 Ma
Mesabi
Emily
Marquette
Gogebic
Cuyuna
Iron River-Crystal Falls,
Felch, Menomenee
Google Earth 2010
“EXTRATERRESTRIAL DEMISE OF BANDED IRON FORMATIONS
1.85 BILLION YEARS AGO”
“MIXING EVENT”
ANOXIC
SUBOXIC
Modified from: Slack and Cannon, 2009: Geology
2010—TACONITE REMAINS A “HOT COMMODITY”
…And
there may be other uses for Taconite
that we have not yet discovered!
New developments on the
MESABI IRON RANGE
Former LTV plant—now Polymet
• 6 mines running at full capacity
• Planned new mines and facilities
• Iron extraction from old mine waste
Source: Iron Range Resources “RangeView” w.2008-2009
MESABI RANGE FUTURE
“Laurentian Vision”
HIBBING
Digital Elevation Model
Central Mesabi Iron Range
DNR, 1999
PIT LAKE PROTOTYPE
Laurentian Vision
University of Minnesota
Landscape Architecture
ROCKY
TACONITE
Silver Bay, MN
ROCKY TACONITE
Symbolic of a new era—The transition
of taconite to steel”
Dedicated to those whose genius and
labors are responsible for the
utilization of taconite, for converting a
USELESS ROCK into a useful and
valuable product, and a huge new
industry in Minnesota….
THE END
Dunka taconite pit 2004