Richard Lee Armstrong (August 4, 1937 – August 9, 1991) was an American-Canadian scientist who was an expert in the fields of

radiogenic A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay. It may itself be radioactive (a radionuclide) or stable (a stable nuclide). Radiogenic nuclides (more commonly referred to as radiogenic isotopes) form some of ...

isotope geochemistry Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various Chemical element, elements. Variations in isotopic abundance are measured by isotope-ratio mass spectrometry, ...

and

geochronology Geochronology is the science of Chronological dating, determining the age of rock (geology), rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, ...

geochemical Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ...

evolution of the earth,

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

of the

American Cordillera The American Cordillera ( ) is a chain of mountain ranges (cordilleras), consisting of an almost continuous sequence of mountain ranges that form the western "backbone" of the Americas. Aconcagua is the highest peak of the chain. It is also the ...

, and large-magnitude crustal extension. He published over 170 scientific papers.

Education

Armstrong was born in

Seattle, Washington Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...

. In 1955, he moved to

New Haven, Connecticut New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 United States census, 2020 U.S. census, New Haven is List ...

, to attend

Yale University Yale University is a Private university, private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the List of Colonial Colleges, third-oldest institution of higher education in the United Stat ...

. He obtained his BSc in 1959 and a PhD in 1964. He stayed at Yale as assistant and associate professor in the geology department until 1973. While he was a Yale professor, he took two leaves, the first in 1963–1964 on a National Science Foundation Postdoctoral Fellowship at the University of Berne, and in 1968–1969 as a Morse and Guggenheim Fellow at the

Australian National University The Australian National University (ANU) is a public university, public research university and member of the Group of Eight (Australian universities), Group of Eight, located in Canberra, the capital of Australia. Its main campus in Acton, A ...

and

California Institute of Technology The California Institute of Technology (branded as Caltech) is a private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small group of institutes ...

Career

In 1973, Armstrong moved to

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

, British Columbia, Canada to be an associate professor at the

University of British Columbia The University of British Columbia (UBC) is a Public university, public research university with campuses near University of British Columbia Vancouver, Vancouver and University of British Columbia Okanagan, Kelowna, in British Columbia, Canada ...

. He was eventually made a full professor. In 1979, he became a Canadian citizen. Armstrong studied the

chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the deter ...

of magmatism,

metamorphism Metamorphism is the transformation of existing Rock (geology), rock (the protolith) to rock with a different mineral composition or Texture (geology), texture. Metamorphism takes place at temperatures in excess of , and often also at elevated ...

, and

tectonics Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

of western North America. He utilized several methodologies, including

Potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

Argon Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abu ...

Rubidium Rubidium is a chemical element; it has Symbol (chemistry), symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have ...

Strontium Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, it is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to ...

Uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

Lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

and

Neodymium Neodymium is a chemical element; it has Symbol (chemistry), symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth element, rare-earth metals. It is a hard (physics), hard, sli ...

Samarium Samarium is a chemical element; it has symbol Sm and atomic number 62. It is a moderately hard silvery metal that slowly oxidizes in air. Being a typical member of the lanthanide series, samarium usually has the oxidation state +3. Compounds of s ...

to obtain isotopic data. Armstrong's early theories guided research for a generation. His views were controversial and contested by many prominent isotope geochemists. It took decades for other scientists to accept his ideas. Before he died, Armstrong was vindicated through the recognition he received for his model of crustal recycling at the 1990 ICOG meeting in

Canberra Canberra ( ; ) is the capital city of Australia. Founded following the Federation of Australia, federation of the colonies of Australia as the seat of government for the new nation, it is Australia's list of cities in Australia, largest in ...

after presenting a paper on "The Persistent Myth of Crustal Growth". Most of Armstrong's effort was spent systematically building an enormous database on the geochronology of the North American Cordillera. This database highlighted the magmatic evolution of the region and continues to provide a wealth of information to the scientific community. Armstrong was an active member of the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hi ...

and editorial boards for several journals. He participated in the peer review process of the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

and Canada's

Natural Sciences and Engineering Research Council The Natural Sciences and Engineering Research Council of Canada (NSERC; , CRSNG) is the major federal agency responsible for funding natural sciences and engineering research in Canada. NSERC directly funds university professors and students as ...

. He also participated in Canada's Lithoprobe program a national geoscience research project and contributed to the development of the geological timescale, particularly the Triassic. On August 9, 1991, Armstrong died of liver cancer, five days after his 54th birthday.

Accolades

*1981, made a fellow of the

Royal Society of Canada The Royal Society of Canada (RSC; , SRC), also known as the Academies of Arts, Humanities, and Sciences of Canada (French: ''Académies des arts, des lettres et des sciences du Canada''), is the senior national, bilingual council of distinguishe ...

*1986, awarded a

Killam Prize The Killam Prize (previously the Izaak Walton Killam Memorial Prize) was established according to the will of Dorothy J. Killam to honour the memory of her husband Izaak Walton Killam. Five Killam Prizes, each having a value of $100,000, were awa ...

by the University of British Columbia *1990, awarded the Logan Medal by the Geological Association of Canada *The Richard Lee Armstrong Endowment Fund, an endowed scholarship, was established at the Department of Earth Sciences, University of British Columbia after his death *A new radiogenic isotope laboratory was dedicated to his memory by the University of British Columbia * The

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

21362 Dickarmstrong

Often cited and recognized papers

*Armstrong, R.L.. 1966. K-Ar dating of plutonic and volcanic rocks in orogenic belts: Age determination by potassium argon: ''Heidelberg, Springer-Verlag'', pp. 117–133. *Armstrong, R.L.. 1968. A Model for the Evolution of Strontium and Lead Isotopes in a Dynamic Earth: ''Reviews of Geophysics'', v. 6, pp. 175–199. *Armstrong, R.L.. 1972. Low-angle faults, hinterland of the Sevier orogenic belt, eastern Nevada and western Utah: ''Geological Society of America Bulletin'', v. 83, pp. 1729–1754. *Armstrong, R.L.. 1981. Radiogenic isotopes; The case for crustal recycling on a near-steady-state no-continental-growth Earth: ''Royal Society of London Philosophical Transactions'', v. 301, pp. 443–472. *Armstrong, R.L., 1988. Mesozoic and Early Cenozoic Magmatism of the Canadian Cordillera. doi: 10.1130/SPE218-p55 GSA Special Papers 1988, v. 218, pp. 55–92 *Armstrong, R.L, Parrish, R.. 1990. A geologic excursion across the Canadian Cordillera near 49°N (Highways 1 and 3 from Vancouver to southwestern Alberta and on to Calgary, Alberta): ''Geological Association of Canada Meeting, Vancouver, May, Field Trip Guidebook'', 71 p. *Harland, W.B.; Armstrong, R.L.; Cox, A.V.; Craig, L.E.; Smith, A.G.; Smith, D.G., 1990. ''A Geologic Time Scale'', 1989 edition. Cambridge University Press: Cambridge, pp. 1–263. *Armstrong, R.L., 1991. The Persistent Myth of Crustal Growth. ''Austral. J. Earth Sci.'', Vol: 38:613–630

References

External links

Geolog- Spring 2003Isotope Geochemistry
{{DEFAULTSORT:Armstrong, Richard Lee 1937 births 1991 deaths 20th-century Canadian geologists Fellows of the Royal Society of Canada Yale University alumni Deaths from cancer in British Columbia California Institute of Technology faculty Academic staff of the University of British Columbia Faculty of Science Scientists from Seattle Scientists from Vancouver American emigrants to Canada Yale University faculty Logan Medal recipients Deaths from liver cancer in Canada Presidents of the Canadian Association of Physicists