Jakob Sederholm

Jacob John Sederholm ( born July 20, 1863 in Helsinki, † June 26, 1934 ) was a Finnish petrologist doing research mainly in the field of migmatites, it goes back to this notion.

Sederholm was his life plagued by diseases and chose the study of the geologist to work in the open air can. He studied first in Helsinki, Stockholm and then finally in Heidelberg. He returned to Finland for the Geological Survey (Finnish: Geologian tutkimuskeskus ) to work. In 1893 he was made director of the service, a post he retained until his death 40 years later.

Sederholm research in the Precambrian basement of Finland and initiated a program for mapping, published in the framework of 1899-1925 many geological maps and descriptions. The gneisses in his study area, the Baltic shield, are often of mixed composition by granitic layers with metamorphic exchange store. Sederholm called this rock type migmatite and saw it as a product of magmatic intrusions in metamorphic rocks at depth.

Throughout his career, he published more than 250 scientific papers, the Murchison Medal of the Geological Society of London (1928) and the Penrose Medal of the Geological Society of America received ( also 1928). The mineral Sederholmit, a nickel -selenium mineral, is named after him.

In addition to his geological work Sederholm was a member of the Finnish Parliament and traveled on its behalf to meetings of the League of Nations. He was a member and two-time President of the Economic Society of Finland.