J Harlen Bretz

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J Harlen Bretz (1949)

Jerry Harlen Bretz (born September 2, 1882 in Saranac , Michigan , † February 3, 1981 in Homewood , Illinois ), better known under the name J Harlen Bretz, was an American geologist who became famous for his research in the Channeled Scablands . His research eventually led to the recognition of the theory of great floods in Northwest America , the Missoula floods at the end of the last ice age . In addition, he wrote an important work on the shape and origin of karst caves and authored The Caves of Missouri , a detailed description of the caves of Missouri .

Early career

Bretz was born as the eldest child of Oliver Joseph Bretz and Rhoda Maria Howlett, a farming couple from Saranac, Michigan. He graduated from Albion College in Albion , Michigan in 1906 with a degree in biology . At college he made the acquaintance of his future wife, Fanny Chalis. After graduating, he became interested in the geology of East Washington .

He began his academic career as a biology teacher at a high school in Seattle . During this time Bretz worked on the glacial geology in the area of ​​the Puget Sound and finally found a job at the University of Chicago , where he received his Ph.D. in geology. He became Assistant Professor of Geology, first at the University of Washington and then at the University of Chicago.

The unheard of hypothesis

Channeled Scablands

In the summer of 1922 and for the following seven years, Bretz carried out field work in the area of ​​the Columbia River Plateau . He had developed an interest in the unusual erosion features of the area after seeing a topographical map of the Potholes Cataract area in 1910 . After he had examined the area around the Grand Coulee , where massive erosion had cut deep through the mighty basalts of the Columbia Plateau basalt , he created the term “Channeled Scablands” in 1923. The area was a desert , but Bretz's theory, bold for his time, presupposed large masses of water, which should have created the landforms found. In a 1925 publication, Bretz called these prehistoric floods the "Spokane Floods", as he assumed that they were caused by meltwater from the Spokane area .

Bretz's theory was rejected by his fellow scientists because, among other things, as a catastrophic theory, it violated prevailing uniformitarianism . In addition, many of his geologist colleagues were not familiar with the conditions in the remote Northwest of America, where Bretz had undertaken his geological research, and because of his young age he himself had no reputation among the specialist colleagues.

The Geological Society of America invited Bretz to a presentation of his research on January 12, 1927. Several other geologists were invited who had a different opinion than Bretz about the cause of the landforms in Washington and rejected his theory. Despite the superiority of the older men, Bretz valiantly defended his theory. The discussion sparked a longstanding and fiercely fought controversy . The weightiest argument against his theory was that he was initially unable to provide a convincing explanation for the origin of the floods. Not until the 1930s did Bretz consider the existence of Lake Missoula as the cause of the flooding. However, he himself was not sure whether this theory was correct. Bretz and his colleague JT Pardee researched in the Scablands until the 1950s.

More than thirty years after it was first published, the theory was finally widely accepted in the light of knowledge about the dynamics of glaciers , ice sheets, and ice reservoirs . The investigations were able to prove that the floods - there were several - came from the formerly existing Lake Missoula and neighboring lakes.

Awards and honors

Bretz was honored with the Penrose Medal of the Geological Society of America in 1979 at the age of 96 . After receiving the medal, he said to his son: "All my enemies are dead, now I can no longer show off to anyone."

Every year Albion College presents the "J Harlen Bretz Award" for the best geologist in the faculty.

Works (selection)

  • 1923: The Channeled Scabland of the Columbia Plateau. In: Journal of Geology . Volume 31, pp. 617-649
  • 1925: The Spokane flood beyond the Channeled Scablands. In: Journal of Geology . Volume 33, pp. 97-115 and 236-259
  • 1942: Vadose and phreatic features of limestone caverns. In: Journal of Geology . Volume 50, No. 6, Part II, pp. 675-811
  • 1956: The Caves of Missouri. Missouri Geological Survey and Water Resources, 490 pp.

References and comments

  1. Bretz did not use a period after the first initial, cf. Bretz, J Harlen (1882-1981). historylink.org
  2. List of the winners of the Penrose Medal (English)
  3. Albion College Department of Geology Departmental Awards (English) ( Memento of 29 May 2010 at the Internet Archive )

Web links