Editing Claude Allègre (section)

== Background and scientific work ==
Allègre's main area of research was in [[geochemistry]].<ref>{{cite web|url=http://www.geochemsoc.org/awards/geochemicalfellows|archive-url=https://web.archive.org/web/20160304023526/http://www.geochemsoc.org/awards/geochemicalfellows|archive-date=4 March 2016|title=Geochemical Fellows|website=Geochemical Society|date=2015|access-date=10 October 2020}}</ref> He started work in this field for his doctoral research, where he focussed on ways of dating rocks using isotope geochemistry; specifically [[radiometric dating]].<ref name=GCA>{{cite journal|url=https://doi.org/10.1016/0016-7037(87)90356-5|first=Claude|last=Allègre|title=Acceptance speech for the V. M. Goldschmidt award|journal=Geochimica et Cosmochimica Acta|volume=51|year=1987|issue=6 |pages=1773–1774|doi=10.1016/0016-7037(87)90356-5|bibcode=1987GeCoA..51.1773A |url-access=subscription}}</ref> After realising that there was no laboratory in France where he could make measurements with the accuracy he was seeking, Allègre received a [[NATO]] grant and spent the summer of 1965 working at the [[California Institute of Technology]] in [[Pasadena, California|Pasadena]], California. Here, Allègre began working with [[Jerry Wasserburg]], and learned the techniques required for [[Rubidium–strontium dating|rubidium-strontium dating]] of rocks by [[mass spectrometry]]. Allègre returned to France, and over the next three years built a laboratory and began making isotopic measurements. He completed his doctoral thesis, titled 'introduction to the systematic geochronology of open systems', at the University of Paris in 1967.<ref>{{cite web|url=https://biblio-n.oca.eu/biblio/pmb3.0/opac_css/index.php?lvl=serie_see&id=2383|title= Introduction à la géochronologie systématique des systèmes ouverts. 3 volumes|first=Claude|last= Allègre|year=1967|via=Côte d'Azur Observatory library}}</ref> In 1968, he took up a position at the [[Institut de Physique du Globe de Paris]] (IPGP), where he then spent much of his scientific career,<ref name=GCA/> including a ten year stint as IPGP director from 1976 to 1986.<ref name=FRA>{{cite web|url=https://francearchives.gouv.fr/fr/authorityrecord/FRAN_NP_051381|title=Allègre, Claude (1937–)|work=FranceArchives, Portail national des Archives}}</ref>

Over the next thirty years, Allègre and his research students, post-doctoral researchers and collaborators developed techniques that meant they were able to measure isotope abundances in rocks and minerals by mass spectrometry that set new standards of sensitivity and precision. This allowed Allègre and his team to develop new ideas about the age and chemical evolution of the outer parts of the Earth, and also provide new information and insight into the early history of the [[Solar System]], by dating meteorites.<ref name="auto">{{cite web|url=https://royalsociety.org/people/claude-allegre-10984/|title=Professor Claude Allegre ForMemRS|via=Royal Society}}</ref> Allègre defined the new field of 'chemical geodynamics'. This combined data from isotope geochemistry with constraints from geophysics to develop ideas about the long-term chemical evolution of the planet, from core-formation to crustal growth.<ref name="auto3">{{cite journal|first=G.R.|last=Tilton|title=
Introduction of Claude Allègre for the V. M. Goldschmidt Award 1986|journal=Geochimica et Cosmochimica Acta|volume=51|year=
1987|issue=6 |pages=1771–1772|url=https://doi.org/10.1016/0016-7037(87)90355-3|doi=10.1016/0016-7037(87)90355-3|bibcode=1987GeCoA..51.1771T |url-access=subscription}}</ref>

Allègre's work had a substantial impact on the field of geochemistry, for which he received a number of awards and elections to national academies, including the US [[National Academy of Sciences]] in 1985,<ref name="auto2">{{Cite web|url=https://www.nasonline.org/directory-entry/claude-j-allegre-thmpnk/|title=Claude J. Allègre|website=nasonline.org |via=National Academy of Sciences}}</ref> and the [[Royal Society]] in 2002.<ref>{{Cite web|url=https://www.theguardian.com/education/2002/may/13/highereducation.uk|title=Society defends its scientific decision|first=Polly|last=Curtis|work=The Guardian |date=13 May 2002}}</ref> He was also awarded senior medals for his work, from the Geochemical Society (V.M. Goldschmidt award, 1986) and the [[American Geophysical Union]] (Bowie medal, in 1995).<ref name="auto1">{{cite journal|first=Don L.|last=Anderson|year=1995|title=Allegre receives the William Bowie Medal|url=https://doi.org/10.1029/95EO00331|journal=Eos, Transactions, American Geophysical Union|volume=72|issue=52 |pages=535|doi=10.1029/95EO00331 }}</ref> In 1986, he was jointly awarded the Crafoord Prize with Wasserburg, in recognition of their 'pioneering work in isotope geology'.<ref name="auto4">{{cite web|url=https://www.crafoordprize.se/news/the-crafoord-prize-1986/|title=The Crafoord Prize 1986|via=The Royal Swedish Academy of Sciences|date=1 June 1986}}</ref>

===Scientific administration===
Allègre made many contributions to the organisation of the geological and geochemical sciences in France and Europe throughout his career. In 1981, he became the first president of the [[European Union of Geosciences]] (EUG), which was established to coordinate a biennial scientific congress for geoscientists across Europe.<ref>{{cite web|url=https://www.egu.eu/about/historical-highlights/eug/|title=Historical highlights of the European Union of Geosciences (EUG)|last=Schlich|first=Roland|date=1 October 2003|access-date=6 January 2024}}</ref> The EUG later merged with the European Geophysical Union, to become the European Geosciences Union (EGU), in 2004. In 1988, 
Allègre created the [[European Association of Geochemistry]] and presided over an inaugural international conference on geochemistry in Paris. This led to the establishment of the annual 'Goldschmidt Conferences' of the international geochemistry community, in cooperation with the [[Geochemical Society]] which are held in alternate years in Europe, and in the United States.<ref name=DSA>{{cite journal|first=Albrecht W|last=Hofmann|title=
Citation for presentation of the 2004 distinguished service award to Claude J. Allègre|journal=
Geochimica et Cosmochimica Acta|volume=
70|issue=18|year=2006|page=S19|doi=10.1016/j.gca.2004.07.039 |url=
https://doi.org/10.1016/j.gca.2004.07.039.|url-access=subscription}}</ref> From 1992 to 1997, Allègre was director of the French national geological survey, the [[Bureau de Recherches Géologiques et Minières]].<ref name=FRA/>

In 2004, Allègre was presented with the distinguished service award of the Geochemical Society for his 'enormous' service to the geochemical profession. In his citation, [[Albrecht Hofmann|Al Hofmann]] commented that Allègre's 'actions have not always been popular ... but they have always been guided by far-sighted strategic thinking and planning, and usually by deep insight.' He also characterised Allègre's approach to service as one that involved 'hatching a far-flung idea ... hand picking a few people ... and then letting them do the work.'<ref name=DSA/>

===Scientific works===
Over the course of his career, Allègre published many scientific papers. He also authored a number of scientific monographs and textbooks, including:

* ''Introduction to geochemistry'' (1974)<ref>{{cite book|url=https://books.google.com/books?id=WpkuAAAAIAAJ|last1=Allègre|first1=C.J.|last2=Michard|first2=G.|title=Introduction to Geochemistry|publisher=Springer Netherlands|date=December 1974|isbn=978-90-277-0498-6}}</ref> 
* ''Trace elements in igneous petrology : a volume in memory of Paul W. Gast'' (1978)<ref>{{cite book|last1=Allègre|first1=C.J.|last2=Hart|first2=S.R.|year=1985|title=Trace elements in igneous petrology : a volume in memory of Paul W. Gast|series=Developments in petrology|volume=5|pages=1–272|publisher=Elsevier|isbn=978-0-444-41658-2}}</ref>
* ''From stone to star : a view of modern geology'' (1992)<ref>{{cite book|last=Allègre|first=C.J.|title=From stone to star : a view of modern geology|translator=Deborah Kurmes van Dam|publisher=Harvard University Press|year=1992|pages=287|isbn=978-0-674-83866-6}}</ref>
* ''Isotope geology'' (2008) <ref>{{cite book|last=Allègre|first=C.J.|year=2008|publisher=Cambridge University Press|title=Isotope Geology|translator=Christopher Sutcliffe|isbn=978-0-511-80932-3}}</ref>

Allègre also wrote a number of [[popular science]] texts, on topics such as the history of the Earth and the [[plate tectonic]] revolution. His 1988 book, ''The behaviour of the Earth'', gained praise from reviewers for presenting a perspective on the French scientific contributions to the history of plate tectonics.<ref>{{cite journal|last=Wyllie|first=Peter J.|year=1988|url=https://www.science.org/doi/10.1126/science.242.4884.1451.b|title=Earth Science and History: The Behavior of the Earth. Continental and Seafloor Mobility. Claude Allègre. Harvard University Press, Cambridge, MA, 1988. Translated from the French by Deborah Kurmes van Dam|journal=Science|volume=242|pages=1451–1452|doi=10.1126/science.242.4884.1451.b |url-access=subscription}}</ref> Historian of geology, David Leveson, cautioned that the narrative promoted a  '[[Whig history|Whiggish]]' telling of the story of plate tectonics as one of progress, from the viewpoint of an insider.<ref name="auto5">{{cite journal|title=Whiggism and its sources in Allègre's ''The Behaviour of the Earth''|first=David J.|last=Leveson|journal=Earth Sciences History|volume=10|year=1991|issue=1 |pages=29–37|doi=10.17704/eshi.10.1.p221j6ku9058752l |jstor=24138410 |bibcode=1991ESHis..10...29L |url=https://www.jstor.org/stable/24138410|url-access=subscription}}</ref> While Allègre's account of the new global geology of plate tectonics was 'lyrical' and 'rhapsodic', Leveson argued that Allègre's focus on progress meant that he was not able to successfully place 'mobilist geology in its "proper" sociological context' in this book.<ref name="auto5"/>