Thomas Dibblee

Thomas Wilson Dibblee, Jr. (11 October 1911, in Santa Barbara, California – 17 November 2004, in Santa Barbara, California) was an American geologist best known for his geological mapping. He is also known, together with co-author Mason Hill, for the assertion in 1953 that hundreds of miles of lateral movement had taken place along the San Andreas Fault in California, an idea that was radical at the time, but which has been vindicated by later work and the modern theory of plate tectonics. Dibblee was one of the most prolific field geologists in American history, and over a 60-year career of field mapping, including 25 years with the US Geological Survey, left a legacy of 40,000 square miles (100,000 km²) of geologic maps, covering approximately one fourth of the state of California.