Jules Marcou (April 20, 1824 – April 17, 1898) was a French-Swiss-American geologist.

Biography

He was born in Salins, in the '' département'' of Jura, in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

. He was educated at

Besançon Besançon (, ; , ; archaic ; ) is the capital of the Departments of France, department of Doubs in the region of Bourgogne-Franche-Comté. The city is located in Eastern France, close to the Jura Mountains and the border with Switzerland. Capi ...

and at the Collège Saint Louis,

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

. After completing his studies, he made several trips through Switzerland to recover his health. These travels led him to devote himself to natural science. During these travels, he met Jules Thurmann (1804–1855), who introduced him to

Louis Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he recei ...

. During 1845, he worked with Thurmann on a geological survey of the

Jura mountains The Jura Mountains ( ) are a sub-alpine mountain range a short distance north of the Western Alps and mainly demarcate a long part of the French–Swiss border. While the Jura range proper (" folded Jura", ) is located in France and Switzerla ...

. He was appointed assistant of the mineralogical department of the Sorbonne in 1846, and also classified its collection of fossils. During this time, he conducted geological investigations in various parts of Europe. In 1847 he went to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

as traveling geologist for the '' Jardin des Plantes'', charged with studying the United States and the English possessions in North America. The next year, he joined Agassiz in

Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

, and accompanied him to the

Lake Superior Lake Superior is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

region, visiting the copper mines of the

Keweenaw Peninsula The Keweenaw Peninsula (, ) is a peninsula of the U.S. state of Michigan. Part of the greater landmass of the Upper Peninsula of Michigan, Upper Peninsula, the Keweenaw Peninsula projects about northeasterly into Lake Superior, forming Keweena ...

, Lake Huron, and Niagara. After six months, he returned to

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...

, and sent minerals he had collected to Paris. In January 1849, Marcou directed his attention to the geology of

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

, and

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

. Later he crossed the Allegheny Mountains, visiting the Mammoth Cave and other localities, and then traversed

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

. He returned to Europe for a short time in 1850. In 1853 he published a ''Geological Map of the United States, and the British Provinces of North America''. In 1853 he was hired by the United States government to serve as a geologist for the Pacific Railroad Survey along the 35th parallel, one of a series of explorations of the American West to find possible routes for a transcontinental railroad. In this role he became the first geologist to cross the United States. He subsequently made a geological section extending from the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. In 1855 he became professor of geology and

palaeontology Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geo ...

at the polytechnic school of

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

, but relinquished this office in 1859. His ''Lettres sur les roches du Jura et leur distribution géographique dans les deux hémisphères'' (published 1857...1860) included one of the earliest proposals that a land bridge had once existed between the Old World and New World. In 1861 again returned to the United States, when he assisted

in initiating the Museum of Comparative Zoology, and was in charge of its palaeontological division from 1860 to 1864. Subsequently, he devoted himself to scientific research until 1875, when he again began service for the United States government, and accompanied the Wheeler Survey to

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

Personal life and death

Jules Marcou married Jane Belknap of Boston in 1850. They had two children. He died in

, in 1898 and was interred there in Mount Auburn Cemetery.

Publications

*
Life, letters, and works of Louis Agassiz
' (1895) * ''Cretaceous formations of the Jura'' * ''Dyas (Permian) of Nebraska'' * ''Taconic rocks of Vermont and Canada'' *
American Geological Classification and Nomenclature
' (1888) * ''Geological Map of the World'' (1861, 2nd edition 1875) *
A Little More Light on the United States Geological Survey
' (1892) * ''Lettres sur les roches du Jura et leur distribution géographique dans les deux hémisphères'' (1857–1860) *
Geology of North America
' (1858) *
New research on the origin of the name América
'

References

Sources

* (fr) : Durand-Delga M., Moreau R., ''Jules Marcou (1824-1898) précurseur français de la géologie nord-américaine'', L'Harmattan, 200 pages, 2003.

Biography

Personal life and death

Publications

References

Sources

Further reading