John Rodgers, 89, tectonics scholar

HAMDEN, Conn. -- John Rodgers, a Yale University professor of geology whose research into the Appalachian Range bolstered the theory of continental drift, died March 7 at his home, Yale said. He was 89.

His 1970 book, "The Tectonics of the Appalachians," argued that the Appalachians had once extended south into Mexico and northwestern South America, and from northwest Africa through Spain and Great Britain to Norway and eastern Greenland.

Mr. Rodgers's work gave early support to the theory of continental drift, that the continents were once one giant land mass and have gradually separated and drifted apart over 200 million years.

He also mapped the bedrock geology of Connecticut and was a specialist in stratigraphy, the science of layers of rocks in the earth's crust. He wrote "Principles of Stratigraphy" with colleague Carl Dunbar in 1957.

Mr. Rodgers, a native of Albany, N.Y., received his bachelor's degree and master's degree from Cornell University and his doctorate from Yale.

In 1944, he joined the Military Geology Branch of the United States Geological Survey and was responsible for mapping beachheads from Siberia to China and Japan.

He joined the Yale geology department in 1946 and became a professor in 1962.

Mr. Rodgers was the editor of the American Journal of Science from 1954 until 1995.