Michael Lesher

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Carl Michael Lesher (born 1951) is an American geologist. He is an authority on the geology and origin of nickel-copper-platinum group element deposits, especially those associated with komatiites, their physical volcanology and localization, the geochemistry and petrology of associated rocks, and controls on their composition.

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Life, education, and career

Lesher was born in Indianapolis, Indiana, United States, but has been living and working in Canada beginning in 1975 and continuously since 1997. He holds BSc and MA degrees in geology from Indiana University, and a PhD degree in geology from the University of Western Australia. Between 1975 and 1979, he worked as an Exploration Geologist and Mineralogist for the Iron Ore Company of Canada; between 1982 and 1984, he was a Postdoctoral Research Fellow at the J. Tuzo Wilson Research Laboratories of the University of Toronto; and between 1984 and 1997, he was Professor of Economic Geology at the University of Alabama in Tuscaloosa. In 1997, he was appointed Professor of Economic Geology, NSERC Senior Industrial Research Chair in Mineral Exploration, and Founding Director of the Mineral Exploration Research Centre at Laurentian University in Sudbury, Ontario. In 2010-2011 he served as Director of Mining Initiatives, designing and founding the School of Mines (now Goodman School of Mines). He has been a Visiting Fellow at the Max Planck Institute für Geochemie (1989 and 1991) and the Research School of Earth Sciences at the Australian National University (1990), an Honorary Professor at the Chengdu University of Technology (2000), and a Visiting Professor at Indiana University (2002-2003), and has given plenary, keynote, and invited lectures all over the world. In 2021 he was appointed Professor Emeritus at Laurentian University.

Between 1998 and 2002, Lesher was Leader of the International Union of Geological Sciences- and UNESCO-sponsored International Geological Correlation Program (now International Geoscience Programme) Project 427, Ore-Forming Processes in Dynamic Magmatic Systems. Between 2012 and 2018 he was Principal Investigator and Project Director of the $13M pan-Canadian "Integrated Multi-Parameter Footprints of Ore Systems" project, sponsored by the Natural Sciences and Engineering Research Council of Canada and the Canada Mining Innovation Council. He is currently a Co-Investigator on the $100M Metal Earth program, sponsored by the Canada First Research Excellence Fund and the Northern Ontario Heritage Fund.

Lesher has authored or co-authored over 500 scientific publications, and has served on the editorial boards of Mineralogical Abstracts (1987-1988), The Canadian Mineralogist (1989-1991), Reviews in Economic Geology (1993-1998), and Mineralium Deposita (2010–2016). In addition to his research, he has consulted for mining companies in Australia, Canada, Finland, and the USA.

Honours and awards

Lesher has been awarded the Duncan R. Derry Medal (2007) from the Mineral Deposits Division of the Geological Association of Canada, and co-awarded the Julian Boldy Award (2002) by the Geological Association of Canada, and the Wardell Armstrong Prize (2009) by the Institution of Mining and Metallurgy. He has served as a Society of Economic Geologists Thayer Lindsley Visiting Lecturer (1998-1999) and as a Canadian Institute of Mining and Metallurgy University Lecturer (1997-1998). He is an elected Fellow of the Society of Economic Geologists, the Geological Society of America, and the Geological Association of Canada.

Selected publications

Related Research Articles

<span class="mw-page-title-main">Ore</span> Rock with valuable metals, minerals and elements

Ore is natural rock or sediment that contains one or more valuable minerals concentrated above background levels, typically containing metals, that can be mined, treated and sold at a profit. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining and is therefore considered an ore. A complex ore is one containing more than one valuable mineral.

<span class="mw-page-title-main">Pentlandite</span> Iron–nickel sulfide

Pentlandite is an iron–nickel sulfide with the chemical formula (Fe,Ni)9S8. Pentlandite has a narrow variation range in nickel to iron ratios (Ni:Fe), but it is usually described as 1:1. In some cases, this ratio is skewed by the presence of pyrrhotite inclusions. It also contains minor cobalt, usually at low levels as a fraction of weight.

<span class="mw-page-title-main">Economic geology</span> Science concerned with earth materials of economic value

Economic geology is concerned with earth materials that can be used for economic and industrial purposes. These materials include precious and base metals, nonmetallic minerals and construction-grade stone. Economic geology is a subdiscipline of the geosciences; according to Lindgren (1933) it is “the application of geology”. It may be called the scientific study of the Earth's sources of mineral raw materials and the practical application of the acquired knowledge.

<span class="mw-page-title-main">Skarn</span> Hard, coarse-grained, hydrothermally altered metamorphic rocks

Skarns or tactites are coarse-grained metamorphic rocks that form by replacement of carbonate-bearing rocks during regional or contact metamorphism and metasomatism. Skarns may form by metamorphic recrystallization of impure carbonate protoliths, bimetasomatic reaction of different lithologies, and infiltration metasomatism by magmatic-hydrothermal fluids. Skarns tend to be rich in calcium-magnesium-iron-manganese-aluminium silicate minerals, which are also referred to as calc-silicate minerals. These minerals form as a result of alteration which occurs when hydrothermal fluids interact with a protolith of either igneous or sedimentary origin. In many cases, skarns are associated with the intrusion of a granitic pluton found in and around faults or shear zones that commonly intrude into a carbonate layer composed of either dolomite or limestone. Skarns can form by regional or contact metamorphism and therefore form in relatively high temperature environments. The hydrothermal fluids associated with the metasomatic processes can originate from a variety of sources; magmatic, metamorphic, meteoric, marine, or even a mix of these. The resulting skarn may consist of a variety of different minerals which are highly dependent on both the original composition of the hydrothermal fluid and the original composition of the protolith.

<span class="mw-page-title-main">Sudbury Basin</span> Third largest verified astrobleme on earth, remains of an Paleoproterozoic Era impact

The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geological structure in Ontario, Canada. It is the third-largest known impact crater or astrobleme on Earth, as well as one of the oldest. The crater was formed 1.849 billion years ago in the Paleoproterozoic era.

<span class="mw-page-title-main">Komatiite</span> Magnesium-rich igneous rock

Komatiite is a type of ultramafic mantle-derived volcanic rock defined as having crystallised from a lava of at least 18 wt% magnesium oxide (MgO). It is classified as a 'picritic rock'. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content. Komatiite was named for its type locality along the Komati River in South Africa, and frequently displays spinifex texture composed of large dendritic plates of olivine and pyroxene.

There are several classification systems for the economic evaluation of mineral deposits worldwide. The most commonly used schemes base on the International Reporting Template, developed by the CRIRSCO - Committee for Mineral Reserves International Reporting Standards, like the Australian Joint Ore Reserves Committee - JORC Code 2012, the Pan-European Reserves & Resources Reporting Committee' – PERC Reporting Standard from 2021, the Canadian Institute of Mining, Metallurgy and Petroleum - CIM classification and the South African Code for the Reporting of Mineral Resources and Mineral Reserves (SAMREC). A more detailed description of the historical development concerning reporting about mineral deposits can be found on the PERC web site.

<span class="mw-page-title-main">Layered intrusion</span>

A layered intrusion is a large sill-like body of igneous rock which exhibits vertical layering or differences in composition and texture. These intrusions can be many kilometres in area covering from around 100 km2 (39 sq mi) to over 50,000 km2 (19,000 sq mi) and several hundred metres to over one kilometre (3,300 ft) in thickness. While most layered intrusions are Archean to Proterozoic in age, they may be any age such as the Cenozoic Skaergaard intrusion of east Greenland or the Rum layered intrusion in Scotland. Although most are ultramafic to mafic in composition, the Ilimaussaq intrusive complex of Greenland is an alkalic intrusion.

Kambalda type komatiitic nickel ore deposits are a class of magmatic iron-nickel-copper-platinum-group element ore deposit in which the physical processes of komatiite volcanology serve to deposit, concentrate and enrich a Fe-Ni-Cu-(PGE) sulfide melt within the lava flow environment of an erupting komatiite volcano.

The Widgiemooltha Komatiite is a formation of komatiite in the Yilgarn Craton of Western Australia.

<span class="mw-page-title-main">Kanichee Mine</span>

The Kanichee Mine, also less commonly known as the Ajax Mine, is an abandoned base metal and precious metal mine, located in the Temagami region of northeastern Ontario, Canada. It is near the small unincorporated community of Temagami North, accessed by the Kanichee Mine Road from Highway 11. The Kanichee Mine zone has been explored and mined discontinuously from as early as 1910. During the 20th century, it operated and closed down at least three times, with the most recent being from 1973 to 1976. To date, the discontinuous operation of Kanichee Mine has produced 4.2 million pounds of metal.

Anthony James "Tony" Naldrett, FRSC was an English and Canadian geologist. He was an authority on the geology and origin of nickel-copper-platinum group element deposits, the tectonic setting in which they occur, the petrology of associated rocks, and controls on their composition. He was an expert on the reaction between sulfide and silicate melts, fractional crystallization of sulfide melts, and the role of hydrothermal fluids.

<span class="mw-page-title-main">Creighton Mine</span> Underground mine in Canada

Creighton Mine is an underground nickel, copper, and platinum-group elements (PGE) mine. It is presently owned and operated by Vale Limited in the city of Greater Sudbury, Ontario, Canada. Open pit mining began in 1901, and underground mining began in 1906. The mine is situated in the Sudbury Igneous Complex (SIC) in its South Range geologic unit. The mine is the source of many excavation-related seismic events, such as earthquakes and rock burst events. It is home to SNOLAB, and is currently the deepest nickel mine in Canada. Expansion projects to deepen the Creighton Mine are currently underway.

<span class="mw-page-title-main">Cubanite</span> Copper iron sulfide mineral

Cubanite is a copper iron sulfide mineral that commonly occurs as a minor alteration mineral in magmatic sulfide deposits. It has the chemical formula CuFe2S3 and when found, it has a bronze to brass-yellow appearance. On the Mohs hardness scale, cubanite falls between 3.5 and 4 and has a orthorhombic crystal system. Cubanite is chemically similar to chalcopyrite; however, it is the less common copper iron sulfide mineral due to crystallization requirements.

Louis Jean-Pierre Cabri (born February 23, 1934, in Cairo) is an eminent Canadian scientist in the field of platinum group elements (PGE) mineralogy with expertise in precious metal mineralogy and base metals at the Canada Centre for Mineral and Energy Technology (CANMET). First as Research Scientist and later as Principal Scientist (1996–1999). In the 1970s he discovered two new Cu–Fe sulfide minerals, "mooihoekite" and "haycockite". In 1983 Russian mineralogists named a new mineral after him: cabriite (Pd2SnCu).

The Mineral Exploration Research Centre (MERC) is a semi-autonomous research centre associated with the Harquail School of Earth Sciences at Laurentian University in Sudbury Ontario, Canada, and one of the largest mineral exploration research-teaching clusters in the world. MERC is housed in the Willett Green Miller Mineral and Mining Research Centre on the Laurentian University campus, together with the Ontario Geological Survey, Ontario Geoscience Laboratories, the John B. Gammon Mines Library, and the administrative offices of the Minerals and Mining Division of the Ontario Ministry of Northern Development and Mines.

Mining geology is an applied science which combines the principles of economic geology and mining engineering to the development of a defined mineral resource. Mining geologists and engineers work to develop an identified ore deposit to economically extract the ore.

Sarah-Jane Barnes is a British-Canadian geologist, who is a professor at the Université du Québec à Chicoutimi and director of LabMaTer.

An orogenic gold deposit is a type of hydrothermal mineral deposit. More than 75% of the gold recovered by humans through history belongs to the class of orogenic gold deposits. Rock structure is the primary control of orogenic gold mineralization at all scales, as it controls both the transport and deposition processes of the mineralized fluids, creating structural pathways of high permeability and focusing deposition to structurally controlled locations.

Thomas "Tom" Seward Lovering was an American geologist, known for his innovative field and laboratory research on relations between mineable ore deposits and hydrothermal alteration of wall rock.

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