View source for Physics:Uranium mining in the Bancroft area

{{Short description|History of mining in Bancroft, Canada}}
{{Use Canadian English|date=March 2022}}
[[File:Entrance Sign, Madawaska Mine.jpg|thumb|alt=Wooden white sign with "MADAWASKA MINES LIMITED"|Madawaska Mine entrance sign, 1985]]
[[Chemistry:Uranium|Uranium]] mining around Bancroft, Ontario, was conducted at four sites, beginning in the early 1950s and concluding by 1982. Bancroft was one of two major uranium-producing areas in Ontario, and one of seven in Canada, all located along the edge of the [[Place:Canadian Shield|Canadian Shield]]. In the context of mining, the "Bancroft area" includes Haliburton, Hastings, and Renfrew counties, and all areas between Minden and Lake Clear. Activity in the mid-1950s was described by engineer A.&nbsp;S. Bayne in a 1977 report as the "greatest uranium prospecting rush in the world".

As a result of activities at its four major uranium mines, Bancroft experienced rapid population and economic growth throughout the 1950s. By 1958, Canada had become one of the world's leading producers of uranium; the $274 million of uranium exports that year represented Canada's most significant mineral export. By 1963, the federal government had purchased more than $1.5 billion of uranium from Canadian producers, but soon thereafter the global supply uranium market collapsed and the government stopped issuing contracts to buy. Mining resumed when uranium prices rose during the [[Finance:1970s energy crisis|1970s energy crisis]], but this second period of activity ended by 1982.

Three of the uranium mines are decommissioned, and one is undergoing [[Earth:Land rehabilitation|rehabilitation]]. A twofold increase in lung cancer development and mortality has been observed among former mine workers.<ref name=":8" />{{rp|iii}} Bancroft continues to be known for gems and mineralogy.

== Geology and mineralogy ==
[[File:Grenville extent.gif|thumb|alt=map of North America with a 350km wide band running from south west to north east, inlay with the same band existing in the extreme north west of Scotland|Extent of the Grenville Province (in orange) in North America and Scotland]]During the most recent ice age, in the area of what is now Bancroft, Ontario, ancient glaciers removed soil and rock, exposing the Precambrian granite that had been the heart of volcanic mountains on an ancient sea bed. During the Grenville orogenies, sedimentary rocks were transformed by heat and pressure into banded gneiss and marble, incorporating gabbro and diorite (rich in iron and other dark minerals).<ref name=":1">{{Cite book |last=Reynolds |first=Nila |url=https://digitalcollections.ucalgary.ca/archive/Bancroft--a-Bonanza-of-Memories-2R3BF1O7WCUJ7.html |title=Bancroft. A Bonanza of Memories |publisher=The Bancroft Centennial Committee |year=1979 |pages=184–193, 223 |oclc=8091686 |access-date=9 July 2023 |archive-url=https://web.archive.org/web/20230709150438/https://digitalcollections.ucalgary.ca/archive/Bancroft--a-Bonanza-of-Memories-2R3BF1O7WCUJ7.html |archive-date=9 July 2023 |url-status=live}}</ref>{{rp|184}} Some uranium ores in these structures are about 1,000 million years old, while others are understood to be 1,200 million years old.<ref name=":13">{{Cite journal |last1=Wakefield |first1=Jeffery |title=The Geology of Gentry's "Tiny Mystery" |url=https://www.tandfonline.com/doi/abs/10.5408/0022-1368-36.3.161 |url-status=live |journal=[[Organization:National Association of Geoscience Teachers|Journal of Geological Education]] |date=1988 |volume=36 |issue=3 |pages=161–175 |doi=10.5408/0022-1368-36.3.161 |bibcode=1988JGeoE..36..161W |archive-url=https://web.archive.org/web/20230610022841/https://www.tandfonline.com/doi/abs/10.5408/0022-1368-36.3.161 |archive-date=10 June 2023 |access-date=10 June 2023}}</ref>{{rp|167}}

In Canada, 99% of known uranium occurrences and 93% of properties producing uranium are located on the [[Earth:Shield (geology)|geological shield]] known as the [[Place:Canadian Shield|Canadian Shield]], almost all on the western and southern edges of it.<ref name=":2" />[[File:Uraninite in Pegmatite (48002874171).jpg |thumb|right|alt=A black and silver-coloured rock with protruding crystals appearing with 4, 5 and 6 sides| Uraninite in pegmatite, from Haliburton County]]
The Grenville Province in Eastern Canada has small quantities of uranium-thorium-[[Chemistry:Rare-earth element|rare earth element]] in granitic pegmatite<ref name=":17">{{Cite journal |last1=Desbarats |first1=A. J. |last2=Percival |first2=J. B. |last3=Venance |first3=K. E. |date=2016-04-01 |title=Trace element mobility in mine waters from granitic pegmatite U–Th–REE deposits, Bancroft area, Ontario |url=https://www.sciencedirect.com/science/article/pii/S0883292716300336 |journal=Applied Geochemistry |language=en |volume=67 |pages=153–167 |doi=10.1016/j.apgeochem.2016.02.010 |bibcode=2016ApGC...67..153D |issn=0883-2927}}</ref> which appear in numerous locations around the Bancroft area,<ref name=":17" /> giving Bancroft the moniker of the "Mineral Capital of Canada".<ref name="Eyles">{{Cite book |last=Eyles |first=Nick |title=Ontario Rocks: Three Billion Years of Environmental Change |publisher=Fitzhenry & Whiteside |year=2002 |isbn=9781550416190 |location=Markham, Ontario |pages=64 |author-link=Nick Eyles}}</ref> The "Bancroft area" includes Haliburton, Hastings, and Renfrew counties, and all areas between Minden and Lake Clear.<ref name=":0">{{Cite journal |last=McDougall |first=Raymond |date=2019-09-03 |title=Mineral Highlights from the Bancroft Area, Ontario, Canada |journal=Rocks & Minerals |volume=94 |issue=5 |pages=408–419 |doi=10.1080/00357529.2019.1619134 |bibcode=2019RoMin..94..408M |s2cid=201298402}}</ref>{{rp|408}} 

Bancroft is unusual as one of the limited global locations where uranium is extracted from intrusive rocks, notably the only one from the pegmatite type.<ref name=":19">{{Cite web |date=May 2020 |title=Geology of Uranium Deposits |url=http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/geology-of-uranium-deposits.aspx |url-status=live |archive-url=https://web.archive.org/web/20220124013903/http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/geology-of-uranium-deposits.aspx |archive-date=24 January 2022 |access-date=2022-01-24 |website=[[Organization:World Nuclear Association|World Nuclear Association]]}}</ref><ref name=":11">{{Cite web |date=2009 |title=World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification |url=https://www-pub.iaea.org/MTCD/publications/PDF/TE_1629_web.pdf |url-status=live |archive-url=https://web.archive.org/web/20220203214815/https://www-pub.iaea.org/MTCD/Publications/PDF/TE_1629_web.pdf |archive-date=3 February 2022 |access-date=24 January 2022 |website=[[Organization:International Atomic Energy Agency|International Atomic Energy Agency]]}}</ref>{{rp|11}} Other locations include the Rössing and [[Engineering:Husab Mine|Husab]]<nowiki/>mines in Namibia, Kvanefjeld in Greenland, Palabora in South Africa, along with the Radium Hill mine and sites in Southern Australia's Olary Province.<ref name=":19" /> [[File:Bancroft uranium mining map.svg|thumb|alt=Map showing Bicroft mine in the centre, Dyno mine 4 miles to the South West, Faraday and Greyhawk mines 4 miles to the north east|Geological map of the major uranium mines near Bancroft {{legend|#7fd496|Granite, granitic gneiss}}{{legend|#87d8f4|Paragneiss para-amphibolite}}{{legend|#db91a4|Marble}}{{legend|#e8ee87|Syenite, syenitic and hybrid gneiss}}{{legend|#a1947a|Metagabbro}}|400px]]The key geological features in the Bancroft area relevant to uranium mining are three circular granitic complexes, each about {{convert|10|km|0}} across. They are (from southwest to northeast):

* The Cheddar complex is a circular double dome of granitic rock surrounded by [[Earth:Gneiss|paragneiss]], para-[[Earth:Amphibolite|amphibolite]], and pyroxene [[Earth:Granulite|granulite]]. All these rocks contain younger granitic and [[Chemistry:Syenite|syenitic]] intrusions.<ref name=":4">{{Cite book |last1=Lang |first1=A. H. |url=https://emrlibrary.gov.yk.ca/gsc/economic_geology_series/16-1962/egs_16.pdf |title=Canadian Deposits of Uranium and Thorium |last2=Griffith |first2=J. W. |last3=Steacy |first3=H. R. |publisher=Geological Survey of Canada - Department of Mines and Technical Surveys |year=1962 |location=Yukon University |pages= |access-date=25 November 2021 |archive-url=https://web.archive.org/web/20211125031158/https://emrlibrary.gov.yk.ca/gsc/economic_geology_series/16-1962/egs_16.pdf |archive-date=25 November 2021 |url-status=live}}</ref>{{rp|177–178}}
* The Cardiff plutonic complex consists mainly of three southeast-dipping cylindrical sheet intrusions: the Centre Lake granite, the Monck Lake granite, and the Deer Lake syenite. They intrude [[Earth:Metasedimentary rock|metasedimentary rock]]s.<ref name=":4" />{{rp|178}}
* The Faraday granite is a sheet of granite covered by [[Earth:Gneiss|gneiss]]es and metagabbro. The Faraday granite sheet dips to the south and it is the southern edge of the Hastings Highland gneiss complex.<ref name=":4" />{{rp|178}}

=== Gems and other resources ===
[[File:Betafite-Zircon-LTH56B.JPG|alt=Hexagonal crystal, with a rough rusty surface|thumb|[[Chemistry:Betafite|Betafite]], zircon collected from Bicroft Mine]]
Finds of gold in nearby Madoc, Ontario, (then known as Eldorado) from 1886 to 1887, inspired many to seek gold around Bancroft. Surface gold was found in October 1897 by R. Bradshaw, {{convert|20|mi|order=flip|abbr=on}} southwest of Bancroft (towards Bobcaygeon). This triggered a rush of prospectors to the area. Iron and magnetic ores were mined from 1882, gold, copper and [[Chemistry:Mica|mica]] from the late 1890s, and [[Chemistry:Marble|marble]] from 1911. More than 1,600 identifiable minerals and non-metallic collectibles can be found in the area,<ref name=":1" />{{rp|184}} including 175 species of gemstones.<ref name=":0" />{{rp|410}}

Aside from uranium, mines in the Bancroft area produced sought-after gemstones of 175 species, most notably [[Chemistry:Calcite|calcite]], [[Chemistry:Clinohumite|clinohumite]], [[Chemistry:Corundum|corundum]], [[Chemistry:Diopside|diopside]], dravite, [[Chemistry:Edenite|edenite]], [[Chemistry:Euxenite|euxenite-(Y)]], ferri-fluoro-katophorite, [[Chemistry:Fluorapatite|fluorapatite]], [[Chemistry:Fluorite|fluorite]], [[Chemistry:Fluoro-richterite|fluoro-richterite]], [[Chemistry:Ilmenite|ilmenite]], [[Chemistry:Kainosite-(Y)|kainosite-(Y)]], [[Chemistry:Molybdate|molybdenite]], [[Chemistry:Nepheline|nepheline]], [[Chemistry:Phlogopite|phlogopite]], crystals of the [[Chemistry:Pyrochlore|pyrochlore]] supergroup, [[Chemistry:Thorite|thorite]], [[Chemistry:Titanite|titanite]], [[Chemistry:Tremolite|tremolite]], [[Chemistry:Uraninite|uraninite]], [[Chemistry:Uranophane|uranophane]], and [[Chemistry:Zircon|zircon]]. Madawaska Mine produced samples of the very rare [[Chemistry:Kainosite-(Y)|kainosite-(Y)]], globally renowned samples of the common [[Chemistry:Calcite|calcite]] and [[Chemistry:Fluorite|fluorite]], "superb" samples of [[Chemistry:Ilmenite|ilmenite]], and "fine" samples of [[Chemistry:Molybdenite|molybdenite]].<ref name=":0" />{{rp|410-417}}
{| class="wikitable"
|+Resources (other than uranium and gems) extracted in the Bancroft area
!From
!Resource
!Locations mined
|-
|1882
|Iron
|Coe Hill, Mayo (now Carlow/Mayo), Egan Creek (now Bancroft)
|-
|1882
|Magnetic ore, [[Chemistry:Arsenopyrite|arsenical pyrites]] and [[Chemistry:Quartz|quartz]]
|Bradshaw
|-
|1897 
|Gold
|Bancroft
|-
|1898
|[[Chemistry:Corundum|Corundum]]
|Carlow, Raglan
|-
|1899
|Copper
|Dungannon, Cardiff, Maynooth
|-
|1899
|[[Chemistry:Mica|Mica]]
|Cardiff, Paudash Lake
|-
|1905
|[[Chemistry:Sodalite|Sodalite]]
|Princess Sodalite Mine, near Bancroft
|-
|1911
|[[Chemistry:Marble|Marble]]
|Faraday, Dungannon
|}
Marble mined in Bancroft was used to make the floor of the Whitney Block and the Royal Ontario Museum.<ref name="Eyles" />

== Uranium mining ==
{{OSM Location map
|   coord = {{coord|44.991512|-77.985764}}
|    zoom = 10
|   width = 300
|  height = 200
| caption = Locations of locations around Bancroft. 1 - Faraday/Madawaska, 2 - Bicroft Mine, 3 - Dyno Mine, 4 - Greyhawk Mine, 5 - Cheddar Ghost town

|      label1 = Faraday/Madawaska
| mark-coord1 = {{coord|45.02083|-77.92500}}
|  label-pos1 = left
| mark-title1 = Faraday/Madawaska
| mark-description1= Point1 descr

|      label2 = Bicroft Mine
| mark-coord2 = {{coord|44.99722|-78.03500}}
|  label-pos2 = top
| label-offset-x2 = 10
| mark-title2 = Bicroft Mine
| mark-description2= Point2 descr

|      label3 = Dyno Mine
| mark-coord3 = {{coord|44.95000|-78.09778}}
|  label-pos3 = left
| mark-title3 = Dyno Mine
| mark-description3= Point3 descr

|      label4 = Greyhawk Mine
| mark-coord4 = {{coord|45.03194|-77.89556}}
|  label-pos4 = left
| mark-title4 = Greyhawk Mine
| mark-description4= Point4 descr

|      label5 = Cheddar (ghost town)
| mark-coord5 = {{coord|44.9843|-78.1361}}
|  label-pos5 = right
| mark-title5 = Cheddar Ghost<br />Town
| mark-description5= Point5 descr
}}Uranium was first discovered in the area of Cardiff, Ontario, in 1922 by prospector W.&nbsp;M. Richardson.<ref name=":1" />{{rp|192}} His find was first called "the Richardson deposit" and later "the Fission property"<ref name=":4" />{{rp|175}} and is located {{convert|2|km}} east of the Wilberforce community of Cardiff township.<ref name=":13" />{{rp|163}} Between 1929 and 1931,<ref name=":4" />{{rp|175}} attempts were made to extract [[Chemistry:Radon|radon]] from the uranium ore<ref name=":2">{{Cite web|date=1 May 1987|title=Radioactive and toxic wastes from the Bancroft Uranium Mines. Where are we going and who is in charge?|publisher=Canadian Institute for Radiation Safety (CAIRS)|location=Toronto, Ontario|url=https://radiationsafety.ca/wp-content/uploads/2012/01/Bancroft.pdf|access-date=25 November 2021|archive-date=25 November 2021|archive-url=https://web.archive.org/web/20211125020855/https://radiationsafety.ca/wp-content/uploads/2012/01/Bancroft.pdf|url-status=live |page=12 }}</ref> dug from a tunnel driven into a hill.<ref name=":13" />{{rp|163}}

In 1943,<ref name=":4" />{{rp|175}} during [[Social:World War II|World War II]], global interest in mining uranium escalated.<ref name=":2" /> The government sent geologists to Bancroft, who concluded that all known uranium deposits were unviable due to accessibility, size and uranium concentration.<ref name=":4" />{{rp|175}} 1948 saw an increase in private staking of claims for uranium, but due to the difficulties in extracting uranium from lower grade ore, none developed into mines.<ref name=":4" />{{rp|176–177}} 

In 1953, "intelligent prospecting and excellent preliminary exploration" by G. W. Burns, R. J. Steele and Arthur H. Shore led successful prospecting of the area.<ref name=":4" />{{rp|177}} Between 1953 and 1956, 100 claims were staked around Bancroft<ref name=":1" />{{rp|192}} and at approximately the same time, another ten mines were started in the Elliot Lake area.<ref name=":3" /> Burns and Steele discovered the Central Lake deposits, which were developed into Bicroft Mine, while Shore's prospect became the Faraday Mine.<ref name=":4" />{{rp|176–177}}Activity in the mid-1950s was described by engineer A.&nbsp;S. Bayne in a 1977 report as the "greatest uranium prospecting rush in the world".<ref>{{Cite web |last=Bayne |first=A. S. |date=31 December 1977 |title=Report on Wilson Uranium Property, Cardiff & Faraday Townships, Eastern Ontario Mining Division, Haliburton & Hastings Counties, Ontario, Canada |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/afri/data/imaging/31C13NW0075/31C13NW0075.pdf |url-status=live |archive-url=https://web.archive.org/web/20220105052333/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/afri/data/imaging/31C13NW0075/31C13NW0075.pdf |archive-date=5 January 2022 |access-date=29 December 2021 |publisher=A. S. Bayne & Company, Consulting Engineers |page=3 |location=Ontario}}</ref>{{rp|3}}

Uranium mining operations in the Bancroft area were conducted at four sites, beginning in the early 1950s<ref name=":1" />{{rp|192}} and concluding by 1982.<ref name=":6" />{{rp|48-49}} Each of these used underground hard-rock mining methods to access and collect uranium ores from the surrounding granite and gneiss.<ref name=":4" />{{rp|5-6}} The mines were:
{| class="wikitable"
|+Major uranium mines in the Bancroft area
!Mine (years active)
!Geological feature
!Ore milled
!Uranium oxide produced
|-
|Faraday Mine {{nowrap|(1954–1964)}}
|rowspan=2|Faraday Granite
|{{convert|2780064|ST|t|order=flip}}<ref name=":6" />{{rp|50}}
|rowspan=2|{{convert|7324858|lb|kg|order=flip|abbr=on}}<ref name=":9">{{Cite book |last1=Masson |first1=S. L. |url=http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/MDC023/MDC023.pdf |title=Radioactive Mineral Deposits of the Pembroke-Renfrew Area |last2=Gordon |first2=J. B. |publisher=Ontario Ministry of Natural Resources |year=1981 |isbn=0774349204 |pages=63 |access-date=2 February 2022 |archive-url=https://web.archive.org/web/20220202210455/http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/MDC023/MDC023.pdf |archive-date=2 February 2022 |url-status=live}}</ref>{{rp|61}}
|-
|Madawaska Mine (1976–1982)
|{{convert|1,811204|ST|t|order=flip}}<ref name=":6" />{{rp|50}}
|-
|Bicroft Mine (1957–1963)
|Cardiff Complex
|{{convert|2470000|t|ST}}<ref>{{Cite web |last1=Parsons |first1=M.B. |last2=Friske |first2=P.W.G. |last3=Ford |first3=K.L. |last4=LeBlanc |first4=K.W.G. |date=2013 |title=Transport and fate of uranium, rare earth elements, and radionuclides from decommissioned tailings at the historical Bicroft Uranium Mine, Ontario |url=http://gacmacwinnipeg2013.ca/files/gacmac_2013_program.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160319043903/http://gacmacwinnipeg2013.ca/files/gacmac_2013_program.pdf |archive-date=19 March 2016 |access-date=19 March 2016 |website=Natural Resources Canada |pages=157–158 (abstract only)}}</ref>
|1957–1960: 49,904&nbsp;kg (133,693&nbsp;lb)<ref name=":6">{{Cite web |last=Proulx |first=Michèle |date=1997 |title=The Uranium Mining industry of the Bancroft Area: an Environmental History and Heritage Assessment |url=https://www.collectionscanada.gc.ca/obj/s4/f2/dsk2/ftp04/mq21696.pdf |url-status=live |archive-url=https://web.archive.org/web/20220105051746/https://www.collectionscanada.gc.ca/obj/s4/f2/dsk2/ftp04/mq21696.pdf |archive-date=5 January 2022 |access-date=27 November 2021 |pages=}}</ref>{{rp|36}}<br>1961–1962: 127,659&nbsp;kg (342,000&nbsp;lb)<ref name=":6" />{{rp|37}}<br>1962–1963: 430,000&nbsp;kg (950,000&nbsp;lb)<ref name=":6" />{{rp|38}}
|-
|Dyno Mine (1958–1960)
|Cheddar Granite
|{{convert|659403|ST|t|order=flip}}<ref name=":10">{{Cite web |title=Ontario Mineral Inventory Record MDI31D16NE00032: Canadian Dyno, Dyno Mine, International Mogul |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NE00032.html |url-status=live |archive-url=https://web.archive.org/web/20220310093027/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NE00032.html |archive-date=10 March 2022 |access-date=2022-01-24 |website=Geology Ontario |publisher=Ontario Ministry of Mines}}</ref>
|{{convert|813381|lb|kg|order=flip|abbr=on}}<ref name=":10" />
|-
|Greyhawk Mine (1957–1959, 1976–1982)
|Faraday Granite
|1957–1959: {{convert|80247|ST|t|order=flip}}<ref>{{Cite web |title=Ontario Mineral Inventory Record MDI31F04SW00036: Greyhawk Mine, Greyhawk |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31F04SW00036.html |url-status=live |archive-url=https://web.archive.org/web/20230318181650/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31F04SW00036.html |archive-date=18 March 2023 |access-date=2022-01-24 |website=Geology Ontario |publisher=Ontario Ministry of Mines}}</ref>
|{{convert|111128|lb|kg|order=flip|abbr=on}}<ref>{{Cite report |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/OFR5717//ofr5717.pdf |title=Granitic Pegamtites of the Bancroft Area, Southeastern Ontario (Open File Report 5717) |last=Goad |first=B. E. |date=1990 |publisher=[[Earth:Ontario Geological Survey|Ontario Geological Survey]] |page=321 |access-date=2 July 2023 |archive-date=2 July 2023 |archive-url=https://web.archive.org/web/20230702182849/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/OFR5717//ofr5717.pdf |url-status=live }}</ref>{{rp|320 & 321}}
|}

=== Bicroft Mine ===

[[File:Bicroft Uranium Mine, 1956.png|alt=Boxy buildings and the mine's head shaft behind ten large tanks, surrounded by trees|thumb|Bicroft mine in 1956]]In 1952 G. W. Burns, an amateur prospector from Peterborough, found uranium deposits 16&nbsp;kilometres (10&nbsp;mi) southwest of Bancroft, near Cardiff township and Paudash Lake. At another property near Centre Lake (between Cheddar and Cardiff), he observed purple rocks which he knew to be fluorspar, an indicator of radioactive geology. He brought the samples to Robert Steele in Peterborough who used a [[Organization:Geiger counter|Geiger counter]] to confirm their radioactivity. The two then formed a partnership and immediately began staking land claims. Their slow careful staking disadvantaged them as others rushed to the area and staked their own claims; nonetheless, their work paid off and they started mining what the Geological Survey of Canada (GCS) confirmed to be uraninite.<ref name=":4" />{{rp|177-180}}

In late 1952, Burns sold his property to a Toronto syndicate that formed into the Centre Lake Uranium Mines Limited, led by C.&nbsp;C. Huston. The company worked on the surface, opened an adit and started diamond drilling, mostly every {{convert|100|ft|m|order=flip}}, sometimes {{convert|50|ft|m|order=flip|abbr=on}} between the holes. A shaft was created in 1954. Simultaneous to this, Croft Uranium Mines Limited, a subsidiary of Macassa Mines Limited, formed in 1953 and discovered uranium north of the original site. In 1955 the two sites were merged under the ownership of Bicroft Uranium Mines Limited, with work focused on the Centre Lake part of the property. A shaft was sunk to {{convert|1300|ft|m|order=flip}} and ten levels created. A treatment plant capable of processing {{convert|1100|ST|t|order=flip}} of ore per day was built and operations started in late 1956. Production in 1957 was {{convert|405271|lb|kg|order=flip|abbr=on}} of U<sub>3</sub>O<sub>8</sub> from ore with a grade of 0.0859%. Production increased to {{convert|1300|ST|t|order=flip}} per day in 1958 and exploration started to the south of the site.<ref name=":4" />{{rp|180-183}} Mining continued until 1963, producing about {{convert|2,470,00|t}} of uranium ore.<ref name=":02">{{Cite journal |last1=Parsons |first1=Michael B. |last2=Friske |first2=Peter W. B. |last3=Laidlow |first3=Allison M. |last4=Jamieson |first4=Heather E. |date=2014 |title=Abstract: Controls on Uranium, Rare Earth Element, and Radionuclide Mobility at the Decommissioned Bicroft Uranium Mine, Ontario |url=https://archives.datapages.com/data/atlantic-geology-journal/data/050/050001/pdfs/52a.htm |journal=Atlantic Geology |language=en-US |volume=50 |issue=1 |pages=Abstract |doi=10.4138/atlgeol.2014003 |doi-broken-date=31 January 2024 |quote=The Bicroft Mine operated from 1957 to 1963, and milled approximately 2,470,000 tonnes of U ore |access-date=25 November 2021 |archive-date=22 November 2021 |archive-url=https://web.archive.org/web/20211122014223/https://archives.datapages.com/data/atlantic-geology-journal/data/050/050001/pdfs/52a.htm |url-status=live }}</ref>

{{convert|2284421|t}} of tailings remain on site in two impoundments.<ref name="LaidlowThesis">{{cite thesis |last1=Laidlow |first1=Allison |title=Characterization of Uranium and Rare Earth Element Mobility and Attenuation Downstream of Decommissioned Tailings Impoundments at the Bicroft Mine near Bancroft, Ontario |date=6 May 2013 |hdl=1974/8022 |url=https://qspace.library.queensu.ca/handle/1974/8022 |access-date=16 June 2023 |archive-date=16 June 2023 |archive-url=https://web.archive.org/web/20230616154529/https://qspace.library.queensu.ca/handle/1974/8022 |url-status=live |degree=MSc |publisher=Queen's University at Kingston}}</ref>{{rp|6}} Repairs to the decommissioned site, including the addition of vegetation over the tailings, were completed in 1980. Subsequent upgrades of the dams were completed in the 1990s.<ref name=":25">{{Cite web |last=Watt |first=Jenn |date=6 October 2020 |title=Sampling near old mine sites finds 'no expected health impacts' |url=https://haliburtonecho.ca/sampling-near-old-mine-sites-finds-no-expected-health-impacts/ |url-status=live |archive-url=https://web.archive.org/web/20230318180801/https://haliburtonecho.ca/sampling-near-old-mine-sites-finds-no-expected-health-impacts/ |archive-date=18 March 2023 |access-date=22 November 2021 |website=Haliburton Echo |language=en-CA}}</ref><ref name=":32">{{Cite web|last=|first=|date=21 September 2020|title=Independent Environmental Monitoring Program: Dyno, Bicroft, and Madawaska Mines|url=https://nuclearsafety.gc.ca/eng/resources/maps-of-nuclear-facilities/iemp/dyno-bicroft-madawaska-mines.cfm|url-status=live|access-date=22 November 2021|website=Canadian Nuclear Safety Commission|language=en|archive-date=1 November 2020|archive-url=https://web.archive.org/web/20201101012135/http://www.nuclearsafety.gc.ca/eng/resources/maps-of-nuclear-facilities/iemp/dyno-bicroft-madawaska-mines.cfm}}</ref><ref>{{Cite web |author= |date=February 1990 |title=Subsurface Investigations and Condition of Dams: Bicroft Mine Site Bancroft, Ontario · U-Links Centre For Community Based Research |url=https://database.ulinks.ca/items/show/4671 |url-status=live |archive-url=https://web.archive.org/web/20211122021623/https://database.ulinks.ca/items/show/4671 |archive-date=22 November 2021 |access-date=22 November 2021 |website=U-Links Centre for Community Based Research |publisher=Golder Associates}}</ref>{{rp|ii}} The site is now a [[Earth:Wetland|wetland]]s.<ref name="LaidlowThesis" />{{rp|29}}

The uranium deposits of Bicroft mine occur in a set of eastward-dipping en-echelon [[Earth:Lens (geology)|lens-shaped]] dykes of [[Chemistry:Syenite|syenite]] and [[Chemistry:Granite|granite]], up to {{convert|80|ft|m|order=flip|abbr=on}} wide and {{convert|400|ft|m|order=flip|abbr=on}} long, which extend over an area of about {{convert|1.75|sqmi|km2|order=flip}} within a north–south oriented belt of [[Earth:Amphibolite|amphibolite]] and paragneiss (the eastern part of the Centre Lake granite). The ore minerals are uranothorite and [[Chemistry:Uraninite|uraninite]]. The uranium-to-[[Chemistry:Thorium|thorium]] ratio is variable. [[Chemistry:Pyroxene|Pyroxene]]-rich granite of this area is richer in thorium.<ref name=":4" />{{rp|157}}

=== Faraday Mine/Madawaska Mine ===
The area that is now known as Madawaska Mine was first mapped by Jack Satterly in the early 1950s.<ref name=":13" />{{rp|167}}

Arthur H. Shore, an independent prospector, first found uranium at his lot on Faraday township in 1949. He founded Faraday Uranium Mines Limited in 1949, but injured himself shortly afterwards.<ref name=":4" />{{rp|182}} Newkirk Mining Corporation led work in 1952, including diamond drilling in December 1952 which helped identify seven main zones of uranium ore. Further drilling the following year identified additional deposits to a depth of {{convert|500|ft|m|order=flip}}. 1954 drilling found more uranium and adits were created. By 1955 it was established that there were {{convert|1660980|ST|t|order=flip}} of ore that was 0.112% U<sub>3</sub>O<sub>8</sub> ([[Chemistry:Uranium oxide|uranium oxide]]). A sale price was agreed in January 1956. A {{convert|863|ft|m|adj=mid|-deep|order=flip}} shaft was sunk from an adit, from which five levels were established. A treatment plant with a {{convert|750|ST|t|order=flip|adj=mid|-per-day}} capacity was built and operations started in April 1957. In 1958, the treatment capacity was increased to {{convert|1350|ST|t|order=flip}} per day in order to support processing of ore from Greyhawk Mine. Production in 1957 was {{convert|405271|lb|kg|order=flip|abbr=on}} from ore with a grade of 0.0859% U<sub>3</sub>O<sub>8</sub>.<ref name=":4" />{{rp|182-183}} Between 1948 and 1964 Faraday Mine had produced $54&nbsp;million of ore.<ref name=":1" />{{rp|192}}{{multiple image
| align             = right
| direction         = vertical
| width             = 240
| image1            = Madawaska Mine Entrance.jpg
| alt1              = A road leading past a gatehouse to a series of industrial buildings
| footer            = 
| image3            = Uraninite-179869.jpg
| caption1          = Madawaska Mine entrance {{circa|1985}}
| caption3          = A lustrous, black, octahedral crystal of uraninite on orange calcite, from Bancroft
}}

After $7 million of investment to [[Earth:Land rehabilitation|rehabilitate]] the mine,<ref name=":1" />{{rp|193}} it reopened as the Madawaska Mine in 1976 and production continued to 1982. The shaft into the uranium-bearing [[Earth:Pegmatite|pegmatite]] reached a depth of {{convert|473|m|ft|0}}.<ref>{{cite web |title=Madawaska Mine (Faraday Mine) |url=http://www.mindat.org/loc.php?loc=542&ob=4 |url-status=live |archive-url=https://web.archive.org/web/20081019003430/http://www.mindat.org/loc.php?loc=542&ob=4 |archive-date=19 October 2008 |access-date=25 November 2021 |website=[[Mindat.org]] <!--data from Geological Survey of Canada Miscellaneous Report 39 -- mindat.org--> |publisher=Hudson Institute of Mineralogy}}</ref> During this period, the mine was producing {{convert|1500|ST|t|order=flip}} of ore per day.<ref name=":1" />{{rp|193}}

In 2015, inspections found improper surface protection of the tailings and the site has been undergoing rehabilitation.<ref name=":32" />

At the Faraday and Madawaska mines, [[Earth:Lens (geology)|lens-shaped]] bodies of ore occur in granitic pegmatite dykes within an area of steeply-dipping [[Earth:Amphibolite|amphibolite]] and metagabbro at the southern edge of the Faraday granite. Uraninite and [[Chemistry:Thorite|uranothorite]] are the principal ore minerals at Faraday and Madawaska. Other radioactive minerals found at this locality include [[Chemistry:Allanite|allanite]], cyrtolite (a uranium-thorium rich variety of [[Chemistry:Zircon|zircon]]),<ref name="Cyrtol">{{cite web |title=Cyrtolite: Mineral information, data and localities |url=https://www.mindat.org/min-7493.html |url-status=live |archive-url=https://web.archive.org/web/20211226222558/https://www.mindat.org/min-7493.html |archive-date=26 December 2021 |access-date=26 December 2021 |website=[[Mindat.org]] |publisher=Hudson Institute of Mineralogy}}</ref> uranophane-α and uranophane-β. The uranium-to-thorium ratio is about 2-to-1. Uranium ore concentrations range from 0.07 to 0.4 per cent U<sub>3</sub>O<sub>8</sub> (uranium-oxide.)<ref name=":4" />{{rp|182-184}}

=== Dyno Mine ===
{{main|Dyno Mine}}[[File:Headframe, July 30 1956, Canadian Dyno Mines Limited, Cardiff Township.png|thumb|alt=A wooden frame above the mine's shaft, an above-ground water tank, and three parked cars|Dyno Mine in 1956]]
Prospector Paul Mullette discovered radioactive occurrences in November 1953 that were sold to Dyno Mines Limited (later Canadian Dyno Mines Limited). The company undertook diamond drilling that same month simultaneous to geological mapping. This identified three zones, resulting in drilling, which discovered two additional zones. Surface diamond drilling of 124 holes at {{convert|200|ft|m|order=flip|adj=on}} intervals occurred through 1954 and 1955. A {{convert|1000|ft|m|order=flip|adj=on}} shaft, in the "B" zone, was sunk creating five levels. A price to sell uranium was agreed, and an ore treatment plant with {{convert|1100|ST|t|order=flip|adj=mid|-per-day}} capacity was started in 1956. Production started in May&nbsp;1958.<ref name=":4" />{{rp|184}}

At Dyno mine, at the eastern edge of the Cheddar granite, five zones of ore occur as uranothorite and uraninite in a set of steeply-dipping [[Earth:Lens (geology)|lens-shaped]] dykes of pegmatitic granite {{convert|3|to|60|ft|m|order=flip|abbr=on|sigfig=1}} wide, which intrude into gneisses. Ore occurs across the full width of narrower dykes (up to about {{convert|12|ft|m|order=flip|abbr=on|disp=sqbr}} wide); in wider dykes, ore is usually restricted to only parts of the dyke. The ores are closely associated with a set of north–south trending fractures. Ore concentrations vary from 0.05 to more than 1.00 per cent U<sub>3</sub>O<sub>8</sub>, averaging 0.093 per cent. The ore often contains magnetite, particularly where the ore is of higher grade. Cyrtolite and allanite also occur.<ref name=":4" />{{rp|184-185}}

=== Greyhawk Mine ===
{{main|Greyhawk Mine}}[[File:Headframe, Greyhawk Uranium Mine, 11 July 1956.png|thumb|alt=A wooden frame above the mine's shaft, two men pushing a small cart on tracks|Greyhawk Mine in 1956]]
Radioactive materials were first discovered in Faraday Township in 1955 by K.&nbsp;D. Thompson and M. Card, two employees of Goldhawk Porcupine Mines Limited who were surveying with [[Organization:Geiger counter|Geiger counter]]s. They found exposed rock to be radioactive across a {{convert|60|by|300|ft|m|order=flip|adj=on}} area. Ownership subsequently shifted to Greyhawk Uranium Mines Limited.<ref name=":4" />{{rp|186}} Diamond drilling followed at 15- to 122-metre (50 to 400&nbsp;ft) intervals at {{convert|450|ft|m|order=flip|adj=on}} depth. An exploration shaft was begun in 1956 and three levels created.<ref name=":4" />{{rp|186}} Operations uncovered no high-grade ore deposits, leaving the average grade below that of other Bancroft mines.<ref name=":4" />{{rp|186}} Mining operations subsequently stopped in 1959.<ref name=":1" />{{rp|192}}

Ore was transferred for processing at the Faraday Mine site, starting August 1957 at a rate of about {{convert|200|ST|t|order=flip}} per day. By the end of 1957, {{convert|19568|ST|t|order=flip}} at a value of <!--$11.40 per ton-->{{convert|11.4|$/ST|$/t|order=flip}} had been shipped. Through 1958, production was {{convert|150|ST|t|order=flip}} per day averaging at 0.082% U<sub>3</sub>O<sub>8.</sub><ref name=":4" />{{rp|186}} The tonnage of ore was 30% less than feasibility estimates.<ref name=":4" />{{rp|186}}[[File:Yellow Cake Uranium (14492248719).jpg|thumb|alt=Crumbly yellowcake, it appears like yellow chalk|[[Chemistry:Yellowcake|Yellowcake]] uranium concentrate produced from uranium ore]]
Faraday Uranium Mines Limited purchased the site in 1962.<ref name=":15">{{Cite web |title=Mineral Deposit Inventory Record MDI31F04SW00036: Greyhawk Mine, Greyhawk |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31F04SW00036.html |url-status=live |archive-url=https://web.archive.org/web/20230318181650/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31F04SW00036.html |archive-date=18 March 2023 |access-date=2021-11-25 |website=Geology Ontario |publisher=Ontario Ministry of Mines}}</ref> Madawaska Mines Limited was formed in 1975 and purchased the mine, as well as the Faraday Mine. Mining operations restarted in 1976 and continued until 1982.<ref name=":15" /><ref name=":2" />{{Rp|page=12}}

After mining, the uranium ore was treated in acid [[Engineering:Leaching (metallurgy)|leaching]] plants located at the mines. The leaching process produced [[Chemistry:Yellowcake|yellowcake]] high-grade uranium compounds which were either processed further at the Port Hope refinery or sold to the US government for processing in that country. Processing uranium ore from Bancroft cost $3.00 per ton<!--this would be a short ton; $3.00 per short ton = $3.31 per tonne. Probably format as: approximately $3.30 per tonne ($3 per short ton).--><ref name=":4" />{{Rp|page=95}}

In the Greyhawk area, metagabbro is intruded by east–west trending pegmatitic granite dykes up to {{convert|60|ft|m|order=flip|abbr=on}} wide. Ore bodies of uranothorite and uraninite with an average length of {{convert|100|ft|m|order=flip|abbr=on}} and average width of {{convert|6|ft|m|order=flip|abbr=on}} occur within these pegmatitic dykes, often at the contact with metagabbro. Radioactive minerals are concentrated in the more [[Earth:Mafic|mafic]] parts of the host rock. Ores of 0.095 per cent U<sub>3</sub>O<sub>8</sub> have been reported from this area.<ref name=":4" />{{Rp|page=186}}

=== Other mines ===
[[File:Thorite-54889.jpg|thumb|alt=Terracotta coloured prism-shaped crystal, rough texture, seems to have about ten sides|[[Chemistry:Thorite|Thorite]] crystal, from Kemp Uranium Mine]]
Located at {{coord|44|59|53.22|N|78|9|42.15|W}}, the Kemp Uranium Mine, sometimes called the Kemp Property or Kemp Prospect, produced uranium and a world-class specimen of [[Chemistry:Thorite|thorite]] between 1954 and 1955.<ref>{{Cite web |title=Ontario Mineral Inventory Record MDI31D16NE00166: Kemp |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NE00166.html |url-status=live |archive-url=https://web.archive.org/web/20211220004945/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NE00166.html |archive-date=20 December 2021 |access-date=2021-12-20 |website=Geology Ontario |publisher=Ministry of Northern Development, Mines, Natural Resources and Forestry}}</ref>

Nu-Age Uranium Mines Limited owned the Old Smokey Occurrence, also known as the Tripp property and the Montgomery property.<ref name=":5">{{Cite web |title=Ontario Mineral Inventory Record MDI31D16NW00199: Nu-Age Uranium Mines Ltd., Old Smokey Occurrence |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31D16NW00199.html |url-status=live |archive-url=https://web.archive.org/web/20220123174603/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NW00199.html |archive-date=23 January 2022 |access-date=2022-01-25 |website=Geology Ontario |publisher=Ministry of Northern Development, Mines, Natural Resources and Forestry}}</ref><ref name=":4" />{{Rp|page=270}} Surveying was done by Nu-Age Uranium Mines in 1955 and by Imperial Oil Limited in 1975.<ref name=":5" /> Although a 50-ton-per-day concentrator was known to be on site in the 1950s, the production quantities are unknown.<ref name=":4" />{{Rp|page=254}}

Blue Rock Cerium Mines Limited started exploratory work for a mine at a location in Monmouth township (now known as Highlands East, Ontario) during 1954.<ref name=":16">{{Cite web |last1=Satterly |first1=J. |last2=Hewitt |first2=D. F. |date=1955 |title=Some Radioactive Mineral Occurrences in the Bancroft Area |url=http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/S002/S002.pdf |url-status=live |archive-url=https://web.archive.org/web/20220125021813/http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/S002/S002.pdf |archive-date=25 January 2022 |access-date=25 January 2022 |website=Government of Ontario}}</ref>{{Rp|page=40-42}}<ref>{{Cite web |title=Ontario Mineral Inventory Record MDI31D16NE00143: Blue Rock, Amalgamated Rare Earth # 2 Prospect |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/MDI/data/records/MDI31D16NE00143.html |url-status=live |archive-url=https://web.archive.org/web/20220123171022/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31D16NE00143.html |archive-date=23 January 2022 |access-date=2022-01-25 |website=Geology Ontario |publisher=Ministry of Northern Development, Mines, Natural Resources and Forestry}}</ref> Silver Crater Mines company purchased the Silver Crater Mine in Cardiff, Ontario in 1953 hoping to find uranium.<ref name=":16" />{{Rp|page=54}} The mine produced [[Chemistry:Betafite|betafite]] crystals, which contained 15% to 20% uranium.<ref>{{cite journal |last1=Steacy |first1=H R |last2=Rose |first2=E R |last3=Moyd |first3=L |last4=Hogarth |first4=D D |date=1982 |title=Some classic mineral collecting areas in southeastern Ontario |journal=[[Earth:The Mineralogical Record|The Mineralogical Record]] |volume=13 |pages=197–213}}</ref>

== Economic and political influence ==
Eldorado Mining and Refining Limited was the crown company that purchased all uranium oxide in Canada; it entered into contracts with mine owners at fixed prices.<ref name=":7">{{Cite report |url=https://archive.org/details/reportofroyworkmine00onta/page/n7/mode/2up?q=bancroft |title=Report of the Royal Commission on the Health and Safety of Workers in Mines. |last=Ham |first=James M. |date=1976 |publisher=Attorney General of Ontario |author-link=James Milton Ham}}</ref>{{rp|85}} Faraday Mine alone produced $54 million of uranium ore, creating a rapid economic boom.<ref name=":1" />{{rp|192}} The mine succeeded due to a combination of economic factors, including Bancroft's geographical proximity to the only uranium processing facility in Canada<ref>''Mining , Milling and Refining of Uranium in Ontario, Final Report, Select Committee on Ontario Hydro Affairs'', December 1980, 4<sup>th</sup> Session, 31<sup>st</sup> Parliament, 29 Elizabeth II, Page 1</ref> (located at Port Hope) and a good road and rail network.<ref name=":6" />{{rp|57}}

Employment of miners in Bancroft started in 1955 and peaked in 1958 at around 1,600 jobs.<ref name=":7"/>{{rp|34 chart}} Mine workers unionized in 1957, forming Local 1006 Bancroft Mine and Mill Worker's Union.<ref name=":1" />{{rp|192}} Housing for miners was quickly established around the mines and in nearby Bancroft village, which extended to cover {{convert|4|sqmi|sqkm|order=flip|spell=in}}. Other construction quickly followed, including two single-men's bunkhouses, a canteen, an eleven-room school, an ice-curling rink, and a recreation center. In 1957, a swimming pool was started.<ref name=":23">{{Cite web|last=Voisin|first=Stella|date=28 July 2007|title=Report on The Caring for Kids in Cardiff Research Project|url=http://fayandassociates.com/pdf/cardiff.pdf|url-status=live|archive-url=https://web.archive.org/web/20211124232751/http://fayandassociates.com/pdf/cardiff.pdf|archive-date=24 November 2021|access-date=25 November 2021|website=Fay And Associates}}</ref>{{rp|10}}

By 1958, Canada had become one of the world's leading producers of uranium; the $274 million of uranium exports that year represented Canada's most significant mineral export.<ref name=":4" />{{rp|1}} By 1963, the federal government had purchased more than $1.5 billion of uranium from Canadian producers, but soon thereafter the global supply uranium market collapsed and the government stopped issuing contracts to buy.<ref>{{Cite thesis |last=Downey |first=Terrence Jame |title=Canadian Government Involvement In The Development Of The Uranium Industry, 1930 To 1963 |date=September 1977 |degree=PhD |publisher=Western University |url=https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=1978&context=digitizedtheses |access-date=9 July 2023 |archive-date=4 March 2021 |archive-url=https://web.archive.org/web/20210304103130/https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=1978&context=digitizedtheses |url-status=live}}</ref>{{rp|160-206}}<ref name=":4" />{{rp|11}} 

Mining in Bancroft initially stopped in 1964 due to global reductions in demand for uranium.<ref name=":12">{{cite news |last=Theilheimer |first=Ish |date=22 March 1982 |title=Area's future uncertain without mine |page=7 |work=Ottawa Citizen}}</ref> Local Catholic priest Henry Joseph Maloney (brother of former Ontario Ombudsman Arthur Maloney, and also brother of Minister of Mines James Anthony Maloney) rallied the community to demand support from the provincial and federal governments. Canadian Prime Minister John Diefenbaker, relying on an old agreement with the United Kingdom to buy uranium from Canada, was able to prolong the life of the mine by eighteen months, giving the community time to plan for the closure.<ref name=":1" />{{rp|193}}

Some mines re-opened during the [[Finance:1970s energy crisis|1970s energy crisis]], although, by the early 1980s, uranium demand was again down, with global energy consumption growing at 2%, much less than the expected 7%.<ref name=":12" /> The price of uranium dropped from US$43.57 per pound in 1979<ref>{{Cite web |title=Consolidated Canadian Faraday Limited 1980 Annual Report |url=https://digital.library.mcgill.ca/hrcorpreports/pdfs/6/630367.pdf |url-status=live |archive-url=https://web.archive.org/web/20220210010653/https://digital.library.mcgill.ca/hrcorpreports/pdfs/6/630367.pdf |archive-date=10 February 2022 |access-date=10 February 2022 |website=McGill University |publisher=Consolidated Canadian Faraday Limited |page=4}}</ref>{{rp||location=Mining Operations}} to US$23.50 per pound in March 1982.<ref name=":12" />

Combined with environmental concerns about the nuclear industry following the Three Mile Island accident and increasing costs of building nuclear power plants, circumstances lead to the cancellation of a contract to buy uranium by Italian energy company Agip.<ref>{{Cite web |title=Mineral Deposit Inventory Record MDI31F04SW00037: Faraday, Madawaska |url=http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31F04SW00037.html |url-status=live |archive-url=https://web.archive.org/web/20211122093526/http://www.geologyontario.mndm.gov.on.ca/mndmfiles/mdi/data/records/MDI31F04SW00037.html |archive-date=22 November 2021 |access-date=2021-11-27 |website=Geology Ontario} |publisher=Ministry of Energy, Northern Development and Mines}}</ref><ref name=":12"/> While the uranium mining at Elliot Lake continued to grow, the remaining uranium mining in Bancroft ended in 1982, closing the mines and jeopardizing the local economy.<ref name=":1" />{{rp|193|location=}}<ref name=":12"/>

== Regulatory environment ==

The Atomic Energy Control Board (AECB) issued licenses for uranium mines and mills in Canada, and began regulating uranium mines in 1977. As a result of this, mines that closed prior to 1977 (i.e. Bicroft and Dyno Mines) were able to abandon their sites without any regulatory oversight. Faraday Mine/Madawaska Mine and Greyhawk Mine both resumed mining from 1976 until 1982, so their operation and closure had AECB oversight.<ref name=":2" /> 

Greyhawk Mine's tailings were processed at the mill located at Madawaska Mine, leaving no tailings on site. As a consequence of this, the primary hazards that are regulated are present only at Faraday/Madawaska Mine, and resulted in ongoing environmental monitoring by AECB's successor organization, the Canadian Nuclear Safety Commission (CNSC).<ref>{{Cite web|date=11 May 2012|title=Record of Proceedings. Request for Exemption from Licensing the Greyhawk and Agnew Lake Closed Uranium Mines without Tailings|url=http://www.suretenucleaire.gc.ca/eng/the-commission/pdf/2012-05-11-Decision-Greyhawk-CMD12-H108-e-Final-Edocs3936764.pdf|url-status=live|website=Canadian Nuclear Safety Commission|access-date=25 November 2021|archive-date=16 November 2021|archive-url=https://web.archive.org/web/20211116010027/http://www.suretenucleaire.gc.ca/eng/the-commission/pdf/2012-05-11-Decision-Greyhawk-CMD12-H108-e-Final-Edocs3936764.pdf}}</ref>{{rp|1|location=}}

== Mineral and environmental legacy ==
After the closure of the mines, the various tailing sites attracted mineral collectors, especially to the annual Rockbound Gemboree in which tourists travelled to Bancroft in search of gems and minerals.<ref>{{cite news |last1=Gladstone |first1=Bill |date=8 August 1985 |title=Rockhounds gather for Gemboree |page=M.12 |newspaper=The Globe and Mail |location=Toronto |id={{ProQuest|386290425}}}}</ref> Reserves of {{convert|200000|ST|t|order=flip}} of ore, averaging 0.065% [[Chemistry:Triuranium octoxide|U<sub>3</sub>O<sub>8</sub>]], remain in the ground at Greyhawk Mine.<ref name=":15" /> Dyno Mine ran out of uranium ore in 1959.<ref name=":23" />{{rp|10|location=}} In 2007,a $3&nbsp;million uranium development project was underway in nearby Haliburton.<ref>{{Cite news|last2=Ebner|first2=David|last1=Wallace|first1=Kenyon|date=2007-12-27|title=Uranium exploration plan stirs health fears|language=en-CA|work=The Globe and Mail|location=Toronto, Ontario|url=https://www.theglobeandmail.com/news/national/uranium-exploration-plan-stirs-health-fears/article1092369/|access-date=2021-11-27|archive-date=27 November 2021|archive-url=https://web.archive.org/web/20211127020009/https://www.theglobeandmail.com/news/national/uranium-exploration-plan-stirs-health-fears/article1092369/|url-status=live}}</ref>

1978 and 1980 studies found that the natural weathering of the [[Chemistry:Granite|granite]] and gabbro rocks left at Greyhawk Mine had caused uranium leaching into the [[Earth:Aquifer|aquifer]] at concentrations ranging between 1.2 and 380 parts per billion, with higher concentrations measured deeper in the water table and in sediments.<ref name=":18">{{cite thesis |last1=Mohamad |first1=Bin Daud |title=A Study of Uranium in Ground Water Around Greyhawk Mine, Bancroft, Ontario |date=June 1980 |hdl=11375/6845 |hdl-access=free |url=https://macsphere.mcmaster.ca/handle/11375/6845 |access-date=25 November 2021 |archive-date=18 March 2023 |archive-url=https://web.archive.org/web/20230318181056/https://macsphere.mcmaster.ca/handle/11375/6845 |url-status=live |degree=MSc |publisher=McMaster University}}</ref>{{rp|iii|location=}}<ref>{{Cite report |url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/16/041/16041292.pdf |title=Origin and Subsurface Migration of Radionuclides from Waste Rock at an Abandoned Uranium Mine Near Bancroft, Ontario |last1=Veska |first1=E. |last2=Cherry |first2=J.A. |date=October 1983 |publisher=Atomic Energy Control Board of Canada |isbn=978-0-315-13554-3 |oclc=16031796 |last3=Sharma |first3=H.D. |access-date=3 March 2022 |archive-date=18 March 2023 |archive-url=https://web.archive.org/web/20230318181650/https://inis.iaea.org/collection/NCLCollectionStore/_Public/16/041/16041292.pdf |url-status=live }}</ref>{{rp|iii|location=}}

Rural Canadians predominantly rely on groundwater for drinking water supply. Mining activity expanded fissures and widened the area of groundwater contamination. Public health concerns around groundwater contamination focus on uranium and thorium, plus the presence of decay products of both.<ref>Desbarats, A J; Percival, J B, ''Groundwater chemistry of uranium-thorium-rare earth element deposits, Bancroft area, Ontario,'' Geological Survey of Canada, Open File 7992, 2016, 65 pages, {{doi|10.4095/297779}}</ref>{{rp|2|location=}}

1988 background radiation levels at parts of Paudash Lake were twenty times the safety limit and lumps of semi-refined uranium lay in the abandoned Dyno mine buildings.<ref name=":14">{{cite news |last=Spears |first=Tom |date=24 November 1988 |title=Who's in charge if things get 'hot'? No one has yet assumed responsibility for nuclear waste in the Bancroft area |page=A32 |newspaper=The Toronto Star |id={{ProQuest|1358755930}}}}</ref> The same year, Crowe Valley Conservation Authority called for greater supervision of radioactive waste.<ref name=":14" /> A 2016 Geological Survey of Canada study noted that 70% of ground water samples taken from diamond drilling holes, mine shafts and adits had uranium concentrates above national drinking water safety standards of {{convert|0.02|mg/l}}.<ref name=":17" /> 2019 sampling found radioactive and hazardous contamination in two of several water samples.<ref name=":32" /> Subsequent inspections in 2020 from nearby locations reported water quality to be within provincial standards.<ref name="davis">{{Cite news |last1=Davis |first1=Greg |date=29 September 2020 |title=3 decommissioned uranium mines near Bancroft, Ont. deemed protected, no health impacts: study |work=Global News |location=Vancouver, British Columbia |url=https://globalnews.ca/news/7366368/bancroft-uranium-mine-safety/ |url-status=live |access-date=11 October 2021 |archive-url=https://web.archive.org/web/20230318180800/https://globalnews.ca/news/7366368/bancroft-uranium-mine-safety/ |archive-date=18 March 2023}}</ref> 

Tailings remain at Bicroft, Madawaska and Dyno mine sites where water sampling by the CNSC is ongoing.<ref name=":3">{{Cite web|last=|first=|date=2014-02-03|title=Uranium mines and mills waste|url=http://nuclearsafety.gc.ca/eng/waste/uranium-mines-and-millswaste/index.cfm#Ontario|url-status=live|access-date=2021-11-25|website=Canadian Nuclear Safety Commission|language=en|archive-date=27 February 2014|archive-url=https://web.archive.org/web/20140227160434/http://www.nuclearsafety.gc.ca/eng/waste/uranium-mines-and-millswaste/index.cfm#Ontario}}</ref> Madawaska, Dyno and Greyhawk mines were managed by EWL Management Limited, until February 2022 when it dissolved into its parent company [[Company:Ovintiv|Ovintiv]].<ref>{{Cite web |last= |date=2022-05-19 |title=Regulatory Action – Ovintiv Canada ULC |url=http://nuclearsafety.gc.ca/eng/acts-and-regulations/regulatory-action/ovintiv-canada-ulc.cfm |access-date=2022-06-23 |website=Canadian Nuclear Safety Commission |language=en |archive-date=23 June 2022 |archive-url=https://web.archive.org/web/20220623163610/http://nuclearsafety.gc.ca/eng/acts-and-regulations/regulatory-action/ovintiv-canada-ulc.cfm |url-status=live }}</ref><ref name=":32" /><ref>{{Cite web |last=Lye |first=Dave |date=1 May 2014 |title=EWL Legacy Mine Properties Perpetual Management Strategy |url=https://gnssn.iaea.org/RTWS/rsls-public/Shared%20Documents/Meetings/2nd%20Workshop,%202014,%20Canada/Presentations/David%20Lye,%20CNSC%20EWL%20-%20May%201,%202014.pdf |url-status=dead |archive-url=https://web.archive.org/web/20220105051738/https://gnssn.iaea.org/RTWS/rsls-public/Shared%20Documents/Meetings/2nd%20Workshop,%202014,%20Canada/Presentations/David%20Lye,%20CNSC%20EWL%20-%20May%201,%202014.pdf |archive-date=5 January 2022 |access-date=2022-04-08 |website=[[Organization:International Atomic Energy Agency|International Atomic Energy Agency]] |publisher=EWL Management Limited}}</ref> Bicroft Mine is owned by [[Company:Barrick Gold|Barrick Gold]]; the owners of all four legacy tailing sites at former mines are responsible for the ongoing management of the sites.<ref name=":32" />

== Health legacy for miners ==
{{multiple image
| direction         = vertical
| image1            = Silicosis simple.jpg
| width1            = <!-- displayed width of image; overridden by "width" above -->
| alt1              = Xray of lungs
| image2            = Silicosis complicada.jpg
| width2            = <!-- displayed width of image; overridden by "width" above -->
| alt2              = Xray of lungs, lighter patches visible
| footer            = X-rays of patients with simple silicosis (top) and complicated silicosis (bottom)
}}
According to a 2012 study published in ''Nature'', there is a "positive exposure-response between silica and lung cancer".<ref>{{Cite journal |last1=Sogl |first1=M. |last2=Taeger |first2=D. |last3=Pallapies |first3=D. |last4=Brüning |first4=T. |last5=Dufey |first5=F. |last6=Schnelzer |first6=M. |last7=Straif |first7=K. |last8=Walsh |first8=L. |last9=Kreuzer |first9=M. |date=Sep 2012 |title=Quantitative relationship between silica exposure and lung cancer mortality in German uranium miners, 1946–2003 |journal=British Journal of Cancer |volume=107 |issue=7 |pages=1188–1194 |doi=10.1038/bjc.2012.374 |pmid=22929885 |pmc=3461166 }}</ref> Uranium mining produces silica-laden dust at a free silica rate of 5–15% in Bancroft, significantly less than the Elliot Lake mines which produced ore with 60–70% free silica.<ref name=":7" />{{rp|36}}

In 1974, the Ontario Workmen's Compensation Board studied 15,094 people who worked in uranium mines in Bancroft and around Elliot Lake for at least one month, between 1955 and 1974. Of those 15,094 people, 94 silicosis cases were found in 1974, of which one was attributed to working a Bancroft mine, i.e. the other 93 were attributed to working in an Elliot Lake mine.<ref name=":7" />{{rp|43, 62, 108}}

According to the Committee on Uranium Mining in Virginia, mines produce [[Chemistry:Radon|radon gas]] which can increase lung cancer risks.<ref>{{Cite report |url=https://www.ncbi.nlm.nih.gov/books/NBK201047/ |title=Potential Human Health Effects of Uranium Mining, Processing, and Reclamation |author1=Committee on Uranium Mining in Virginia |author2=Committee on Earth Resources |date=2011-12-19 |publisher=National Academies Press (US) |language=en |author3=National Research Council Canada |access-date=8 April 2022 |archive-url=https://web.archive.org/web/20220125073108/http://www.ncbi.nlm.nih.gov/books/NBK201047/ |archive-date=25 January 2022 |url-status=live}}</ref> Miners' exposure to radiation was not measured before 1958 and exposure limits were not enacted until 1968. Risks to miners at Bancroft and Elliot Lake mines were investigated and the official report of that investigation quotes a miner:<ref name=":7"/>{{rp|77}}<blockquote>
"We have been led to believe through the years that the working environment in these mines was safe for us to work in. We have been deceived."<ref name=":7"/>{{rp|77}}</blockquote>
The aforementioned 1974 study of 15,094 Ontario uranium miners found 81 former miners who died of lung cancer.<ref name=":7" />{{rp|79}} Factoring in predicted lung cancer rate for men in Ontario led to the conclusion that by 1974 there were 36 more deaths than expected attributable to both Bancroft and Elliot Lake mines,<ref name=":7" />{{rp|80}} with the additional risk appearing to be twice as high for Bancroft miners compared to Elliot Lake miners.<ref name=":7" />{{rp|348}}

A study report for the CNSC undertaken by the Occupational Cancer Research Centre at Cancer Care Ontario tracked the health of 28,959 former uranium miners over 21 years and found a two-fold increase in lung cancer mortality and incidence.<ref name=":8">{{Cite report|date=February 2015 |title=Ontario Uranium Miners Cohort Study Report |url=https://tspace.library.utoronto.ca/bitstream/1807/74748/1/RSP-0308.pdf |publisher=Occupational Cancer Research Centre, Cancer Care Ontario |first1=Garthika |last1=Navaranjan |first2=Colin |last2=Berriault |first3=Paul A. |last3=Demers |first4=Minh |last4=Do |first5=Paul |last5=Villeneuve |via=University of Toronto Library |access-date=27 November 2021 |archive-date=18 March 2023 |archive-url=https://web.archive.org/web/20230318181650/https://tspace.library.utoronto.ca/bitstream/1807/74748/1/RSP-0308.pdf |url-status=live }}</ref>{{rp|35 table 4}} In an article published in ''[[Medicine:The BMJ|The BMJ]]'' (journal of the British Medical Association) reported an increase of lung cancer risk; miners who have worked at least 100 months in uranium mines have a twofold increased risk of developing lung cancer.<ref>{{Cite journal |last1=Navaranjan |first1=Garthika |last2=Berriault |first2=Colin |last3=Do |first3=Minh |last4=Villeneuve |first4=Paul J. |last5=Demers |first5=Paul A. |date=2016-12-01 |title=Cancer incidence and mortality from exposure to radon progeny among Ontario uranium miners |journal=Occupational and Environmental Medicine |volume=73 |issue=12 |pages=838–845 |doi=10.1136/oemed-2016-103836 |pmid=27651479 |s2cid=422365}}</ref> The study is expected to be updated in 2023.<ref>{{Cite web|last1=Mandel|first1=Charles|date=22 July 2021|title=Are Canadian uranium workers still more likely to die from lung cancer?|url=https://www.nationalobserver.com/2021/07/22/news/canadian-nuclear-safety-commission-lung-cancer-study-uranium-workers|access-date=2021-11-27|website=Canada's National Observer|language=en|archive-date=27 November 2021|archive-url=https://web.archive.org/web/20211127020624/https://www.nationalobserver.com/2021/07/22/news/canadian-nuclear-safety-commission-lung-cancer-study-uranium-workers|url-status=live}}</ref>

== See also ==
* [[Physics:Uranium mining in the Elliot Lake area|Uranium mining in the Elliot Lake area]]
* Royal Commission on the Health and Safety of Workers in Mines
*Uranium ore deposits
* List of uranium mines
* List of mines in the Bancroft area
* List of uranium mines in Ontario
* 1974 Elliot Lake miners strike

== References ==
{{reflist}}

[[Category:Mineralogy]]
[[Category:Nuclear power]]
[[Category:Nuclear energy]]

{{Sourceattribution|Uranium mining in the Bancroft area}}