ACHILLE ERNEST OSCAR

JOSEPH

See also:

• ACHILLE ERNEST OSCAR JOSEPH DELESSE (1817-1881)

DELESSE (1817-1881)  , French geologist and mineralogist, was born at Metz on the 3rd of February 1817 . At the age of twenty he entered the Ecole Polytechnique, and subsequently passed through the Ecole des Mines . In 1845 he was appointed to the chair of mineralogy and geology at Besancon; in 1850 to the chair of geology at the Sorbonne in Paris; and in 1864 professor of agriculture at the Ecole des Mines . In 1878 he became inspector-general of mines . In early years as ingenieur des mines he investigated and described various new minerals;, he proceeded afterwards to the study of rocks, devising new methods for their determination, and giving particular descriptions of melaphyre, arkose, porphyry, syenite, &c . The igneous rocks of the Vosges, and those of the Alps, Corsica, &c., and the subject of metamorphism occupied his attention . He also prepared in 1858 geological and hydrological maps of Paris—with reference to the underground water, similar maps of the departments of the Seine and Seine-et-Marne, and an agronomic map of the Seine-et-Marne (188o), in which he showed the relation which exists between the physical and chemical characters of the soil and the geological structure . His annual Revue des progres de geologie, undertaken with the assistance (186o–1865) of Auguste Laugel and afterwards (1865–1878) of Albert de Lapparent, was carried on from 186o to 1880 . His observations on the lithology of the deposits accumulated beneath the sea were of special interest and importance . His separate publications were: Recherches sur l'origine des roches (Paris, 1865); Etude sur le metamorphisme des roches (1869); Lithologie des mers de France et des mers principales du globe (a vols. and atlas, 1871) . He died at Paris on the 24th of March 1881 .