Gerard De Geer

Baron Gerard Jacob De Geer was a Swedish geologist born November 20, 1858, in Stockholm, Sweden, who died July 24, 1943, in Stockholm, and who is best known for his work on varves, the annual sedimentary layers left by retreating glaciers, developing the Swedish Time Scale as a year-by-year chronology of glacial retreat; he first applied the name Ancylus Lake to a Baltic paleolake in 1890, and at the 1910 International Geological Congress he formally introduced the term varve and proposed that geochronology be grounded in varve dating. He served as professor of general and historical geology at Stockholm University from 1897 to 1924, also serving as the university rector from 1902 to 1910 and vice-chancellor from 1911 to 1924, and published Geochronologia Suecica Principles in 1940, described as his longest and best-known work. He won the Vega Medal in 1915 and the Bjorkenska priset in 1917, was elected a Foreign Member of the Royal Society in 1930, and received the Wollaston Medal in 1920.