Léonce Élie de Beaumont

Élie de Beaumont

Léonce Élie de Beaumont. Lithograph by Rudolf Hoffmann, 1857

Jean-Baptiste Armand Louis Léonce Élie de Beaumont , called Élie de Beaumont, (born September 25, 1798 in Canon near Caen , Département Calvados ; † September 21, 1874 ibid) was a French geologist . His most important contribution to science today is the first geological map of all of France. Essential aspects of his theory about the origin of the chain mountains and their cause (presumed contraction of the earth) were relevant for most of the 19th century, but are now considered outdated.

Life

Élie de Beaumont received his education at the Lycée Henri IV. , Where he won first prize in mathematics and physics ; at the École polytechnique , where he passed the final exam as the best; and from 1819 to 1822 at the École des mines (mining school) in Paris , where he developed a decided taste for geology. In 1823 he was selected together with Pierre Armand Dufrénoy to take part in a scientific trip to England and Scotland. Their joint professor, André Brochant de Villiers, wanted to visit the country's mining and smelting plants on the one hand , and study the principles according to which George Greenough's geological map of England (1820) had been made , on the other hand , because a similar map was also intended for France. The first results of the map, drawn up by de Beaumont and Dufrénoy under the direction of Bronchant de Villiers, were presented in 1835 and appeared in 1841.

In 1829 Élie de Beaumont himself was appointed professor of geology at the École des mines . He succeeded Brochant de Villiers, whose assistant he had been since 1827. In 1832 he also took over Georges de Cuvier's chair at the Collège de France . His lectures from 1843 to 1844 were published in two volumes. From 1833 to 1847 he also held the post of chief mining engineer of France, after which he was appointed inspector general. In 1849 he was elected to the American Academy of Arts and Sciences . He was made a French senator by a presidential decree in 1852 ; and after François Arago's death in 1853 he was elected permanent secretary of the Académie des sciences (French Academy of Sciences). In 1861 he was appointed Vice-President of the Conseil général des mines and Grand Officer of the Legion of Honor . In 1868 he became the first director of the newly founded geological state office. His growing reputation secured him membership in the Prussian Academy of Sciences in Berlin (today: Berlin-Brandenburg Academy of Sciences ), and in the Royal Society in London . He was a member of the Society of German Natural Scientists and Doctors . In 1860 he was elected a member of the Leopoldina , in 1864 he was elected to the National Academy of Sciences . Since December 1857 he was a corresponding member of the Russian Academy of Sciences in Saint Petersburg .

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Influenced by Alexander von Humboldt's trip to South America (1799 to 1804), during which von Humboldt also dealt with the spatial distribution of the mountain ranges there, Élie de Beaumont presented a paper that was read out to the Académie des Sciences in 1829 , and which he worked out further until 1852. As a supporter of Cuvier, he took the view that the contact surfaces on which rock packages meet, often at a striking angle, and on which a striking change in the fossil content can often be observed ( discordances ), were caused by catastrophic upheavals in the history of the earth. These “revolutions”, he said, could be traced back to particular phases of mountain building. On the other hand, the investigation of the position of the discordances within the stratigraphic rock sequence would enable the relative dating of these phases of mountain formation. Based on the ideas of René Descartes , Élie de Beaumont saw the cause of the mountain formation in the constant cooling of the once glowing body of the earth and the resulting shrinkage of the earth's crust.

In his first account he distinguished only four different "systems" (or orogenes , as we would say today). Although he encountered so many discordances in the course of his further field work that he had to considerably increase the number of necessary mountain building phases, he stuck to his basic catastrophic concept: the sudden surge of the mountain masses from the underground must have triggered devastating tidal waves that then became too large Mass extinction of flora and fauna resulted. Even if the catastrophic approach has been superseded by actualism since the middle of the 19th century , with its slow, steady development of the earth's history, Élie de Beaumont's idea of ​​the shrinking earth body provided the basic tectonic idea to explain mountain formation until the beginning of the 20th century represent.

In his search for regularities in the course of mountain formations (von Humboldt had already speculated that the main directions of the first mountain ranges could represent a kind of "crystal lattice" on the surface of the solidifying earth), Élie de Beaumont came to the view that all mountain ranges that formed the the same mathematical great circle running parallel on the earth's surface, should also have originated at the same time. He also believed that there was a symmetrical relationship between these great circles, in the form of a network of pentagons ( pentagonal dodecahedron , one of the five Platonic solids ) that covered the entire surface of the earth. Because of his prominent position in the scientific community at the time, Élie de Beaumont was able to maintain this daring theory for a long time, but it was not generally accepted by his contemporaries. A sophisticated criticism of the theory was already exercised by William Hopkins in his birthday address to the Geological Society of London in 1853. Indirectly, however, it turned out to be of great value for geology, since its proponents, in their (unsuccessful) attempts to prove it in the field , contributed significantly to the increase in knowledge about the structure of chain mountains.

Today, instead, the publication of the detailed geological map of France 1: 500,000 is considered to be his greatest work. It appeared from 1840 (with two volumes of text 1841 and 1878). During this time Élie de Beaumont also published many important memoirs on the geology of the country, and after his retirement from the École des mines he oversaw the issuance of the maps almost until his death.

Aftermath

In the history of geology there does not seem to be a theory, however outdated and discredited, except that some of its elements cannot unexpectedly reappear later. In the context of today's plate tectonics one no longer assumes a shrinking earth body, but a largely stable earth radius, nevertheless some theorists are again looking for fixed points under the earth's surface, such as the hot spots under Hawaii and Iceland, where heated mantle material rises in convection cells , and endeavor to connect it to other fixed points, such as in Vietnam and Peru, at which this material is to descend again. Élie de Beaumont would probably have liked the geometric patterns that connect such hypothetical fixed points. Mathematical models for calculating the seabed spread also describe the individual volcanically active sections of the mid-ocean ridges as parts of great circles, and it is assumed that the opening of each ocean elsewhere on the earth's surface leads to the simultaneous formation of a new mountain range.

The 3117 m high Mount Elie de Beaumont in New Zealand and the lunar crater Beaumont are named after him.

Fonts

• Léonce Élie de Beaumont: Recherches sur quelques-unes des révolutions de la surface du globe. Annales des Sciences Naturelles, Vols. 18, and 19; 1829-1830.
• Léonce Élie de Beaumont: Leçon de géologie pratique ; Lectures, 1845 to 1849
• Léonce Élie de Beaumont: Notice sur les systèmes des montagnes. 3 vols., Paris 1852.

literature

• Article Jean-Baptiste Elie de Beaumont in the Encyclopaedia Britannica of 1911. Public domain.
• David R. Oldroyd : Thinking about the Earth. A History of Ideas in Geology. Athlone Press, London 1996, ISBN 0-674-88382-9 (In German: Die Biographie der Erde. On the history of science in geology. Translated from English by Michael Bischoff. Two thousand and one, Frankfurt am Main 1998, ISBN 3-86150-285 -2 ).

Individual evidence

1. ↑ Members of the Society of German Natural Scientists and Doctors 1857
2. ^ Foreign members of the Russian Academy of Sciences since 1724. Jean-Baptiste Armand Louis Léonce Élie de Beaumont. Russian Academy of Sciences, accessed November 14, 2015 (Russian).