James Dwight Dana

James Dwight Dana ( born February 12, 1813 in Utica, New York, † April 14, 1895 in New Haven, Connecticut) was an American geologist, mineralogist and zoologist. He pursued important research on mountain building ( orogeny ), volcanism and the origin and structure of continents and oceans. He was one of the leading representatives of the contraction theory and coined the term syncline.

Life

Soon it became Dana interest in science, which had been nurtured by his teacher at the Utica high school. In 1830 he joined the Yale College to study under Benjamin Silliman. After receiving his doctorate in 1833, he was a math teacher for midshipmen and sailed the Mediterranean.

From 1836 to 1837 he was Sillimans assistant in chemical laboratory of Yale, and in the next four years, he participated as a mineralogist and geologist, under the direction of Charles Wilkes, on a research expedition of the United States in the Pacific Ocean in part. Upon his return to North America in 1842, the work claimed, at its research reports a good part of the next thirteen years.

1844 Dana moved back to New Haven about Sillimans married daughter, and was founded in 1856, after his resignation, appointed holders of Silliman Professor of Natural History and Geology in Yale. He held until 1892 this place. In 1846 he was co-editor and (founded in 1818 by Benjamin Silliman ) in his later years editor in chief of the American Journal of Science and Arts, to which he himself contributed constantly with articles on geology and mineralogy. In the early 50s of the 19th century, he used an intensive correspondence with researchers such as Asa Gray, Louis Agassiz and Charles Darwin. In 1859, he suffered because of the constant revision of a physical breakdown, from which he no longer should fully recover.

In 1888 he founded with James Hall and Alexander Winchell, the Geological Society of America, and was its president in 1890.

Services

At the age of 23 he published a classification of minerals, which is published today in new editions. On the fourth, published in 1854 edition, the system still in use today in a developed form in the English-speaking world of the minerals goes back to Dana.

Already since 1846, Dana had returned to the depression of the ocean basin to the decrease in volume of the earth by cooling. On the other hand he held the ocean basins for very old. In contrast to the Katastrophisten as Léonce Élie de Beaumont, he held the still ongoing contraction process very slow and undramatic. In his opinion, had already formed at the edges of the primordial ocean basins deep crevices that still allowed the ascent of volcanic magma and the uplift of mountain ranges. This he tried to explain particularly the structure of the South American Andes. However, about the same time, researchers made as JH Steel and the brothers Henry Darwin Rogers and William Barton Rogers confusing observations in the Appalachian Mountains. There seemed to be layers that were overturned and set in waves, like a frozen ocean surf. They assumed here the effect of a wave-like motion in the molten interior of the earth. The signs of tectonic movements by lateral pressure, such as folding and foliation of the rocks, but still remained difficult to explain. Dana was now trying to integrate these findings into his theory: While the ocean basins more and more depressed and filled with large amounts of sediments underneath masses of molten material should be pressed by the increasing applied load laterally under the continental margins and accumulate there. He was responsible for the observed folds These lateral evasive movements.

The geologist of the Geological Survey (Geological State Office ) from New York, James Hall had, however, made ​​the observation that in some mountain chains sediment layers with thicknesses of up to 40,000 feet ( 13,000 meters) were open-minded. Since it could have never been so deep oceans, he suspected that only in a few narrow channels of the ocean floor had broken under the applied load. Only in these channels it had then come to the observed folds. Dana took up this idea and coined the term geosyncline for these zones, even if he was not the originator of the concept itself. This contradicted Dana Hall and the popular notion that the orogeny alone ( catastrophic ) vertical movements, such as " survey crater " (after Leopold von Buch ) or collapse basin, would take place. However, Dana complained that Hall could not explain how this " original accumulation lines " should be raised into mountains. To this end, Dana reached back to Élie de Beaumont's " dried- apple - model" of the shrinking earth.

Although Dana always emphasized the ever progressive change of the earth's shape, he was averse to a devout Christian of the new theory of the evolution of living beings long. Only in the last edition of his Manual of Geology he accepted the idea.

Honors

In 1857, Dana was elected a member of the Scholars Academy Leopoldina. In 1874, he was honored by the Geological Society of London with the Wollaston medal in 1877 by the Royal Society with the Copley Medal, and in 1882 by the Royal Society of New South Wales with the Clarke Medal.

A crater on Mars and a rib system ( Magmawülste ) on the Moon are named after him.

Writings

Dana's most famous works were his System of Mineralogy (1837 ) and Manual of Geology (1862 ). A bibliographical list of his writings shows 214 titles of books and articles, the 1835 starts with a review of the state of Vesuvius in 1834. His work on corals and sponges, over the Pacific the geology and crabs, which summarize his reports on the Wilkes expedition, Other works published since 1846. 're The Manual of Mineralogy (1848 ), which is run in expanded form today.

As late work he published Corals and Coral Islands in 1872 and took until 1873 for his thoughts orogeny together. 1887 Dana visited again the Hawaiian Islands and the results of his investigations were published in 1890 under the title of Characteristics of Volcanoes.

His system of Mineralogy has been edited by leading U.S. mineralogists to the middle of the 20th century and over again, so in the 7th edition of Harry Berman, and Clifford Frondel Charles Palache. It was also a compendium of mineral types, which was later adopted by the Glossary of Mineral Species by Michael Fleischer and others. Fleischer worked with William Ebenezer Ford the 6th edition in the 1930s.