A copy made by John Collier in 1883 of his 1881 portrait of Charles Darwin. Darwin was a geologist too, say experts.
Credit: Wikimedia
PORTLAND, OREGON: Darwin was more than a biologist; he was first, and foremost, a geologist, say researchers who presented talks at the Geological Society of America's annual meeting.
Darwin is known mostly for his revolutionary work on understanding the process of evolution and natural selection. But Edward Evenson, a glacial geologist who gave a presentation at the meeting in Portland today, said: "I'm here to try to change that perception."
Evenson, based at Lehigh University in Bethlehem, Pennsylvania, cites geological notes Darwin made during a survey of the east and west coasts of South America after setting sail on the HMS Beagle on 27 December 1831.
Geological maps
"He was interested in sea level change," Evenson said. "Darwin worked like a geologist. He made the first geologic map of southern South America. Early in his career, based on observations he made, Darwin became very interested in the emergence of land from the sea."
By noting that the elevation of the sea wasn't constant, Darwin was one of the first to recognise plate tectonics, Evenson added. Along nearly 2,000 km of the South American coast, for example, he observed beach-like terraces as far as 300 m above the ocean.
Not only did he observe and record such landforms, said Evenson, Darwin wanted to know what they were made of and how they moved along the Earth's crust. He also created detailed geological maps of Patagonia and Tierra del Fuego.
"Remarkable achievement"
This was a "remarkable achievement for his early years," said Robert Dott, a sedimentary geologist at the University of Wisconsin in Madison. "He was always making observations of that sort, which contributed to his most famous theories about evolution."
Along with the properties of the rock he studied, Darwin found fossils of extinct animals and shells. By looking at marine fossils in the Andes, he speculated on "seismic uplifts," and how they can create mountain ranges; a discovery that has become one of Darwin's most significant contributions, Dott said.
Darwin's observations of the ocean after an earthquake in south-central Chile on 20 February 1835 have helped scientists understand what happens in tsunami zones. "He put together a lot of concepts that we now know - 180 years later - are the result of an earthquake and an offset under the sea, pushing this huge wave toward the coast," said Lisa Ely, a geologist at Central Washington University in Ellensburg.
"Darwin, in his early 20s when the Beagle set sail, [was] the age of some of my students," Ely said. "It's quite remarkable the depth of thought and the observations that he made."
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