Thomas Wilson Dibblee, Jr. created a true California legacy with over 70 years of active geologic mapping. Tom mapped more than one fourth of the state of California. His knowledge of regional stratigraphy, structure, and paleontology were basic to understanding much of California's geology.
Descendant of the historic De la Guerra family Tom grew up on his family's ranch, Rancho San Julian. Tagging along with an oil geologist on the ranch when he was 14, Tom discovered he had an aptitude for understanding the rocks and the land. He created his first field map in 1929.
After graduating from Stanford in 1936, he was hired by the newly formed Richfield Oil Corporation. For the next 15 years, Tom mapped some of the most remote areas of the Pacific Coast. As one of his fellow students, Ben Page wrote "(Tom) reveled in the geology and established his legendary reputation for roaming harsh country with the greatest of ease on his own two feet. Moreover, he understood most of what he saw..."
In 1952, Tom began a long career with the U.S. Geological Survey (USGS). The USGS assigned him the task of mapping the geology of the Mojave Desert and then a swath 25 miles on each side of the San Andreas Fault from the Mexican Boarder to the north of San Francisco. In 1953, he and his coworker Mason L. Hill published a significant article on California faults that explained little-understood horizontal displacement along the San Andreas. This paper is considered fundamental to plate tectonics theory. Tom's expert field mapping led to the discovery of oil in Cuyama Valley.
While working out of Richfield's Bakersfield office, Tom met Loretta Escabosa, who was secretary of the exploration department. They were married in 1949 and she was his devoted wife until her passing in 2001.
After retiring in 1978, Tom volunteered his services to map the entire Los Padres National Forest, a project that earned him a presidential volunteer award. During his lifetime, he amassed more than 500 field maps covering approximately 40,000 square miles.
Until recently, Tom remained continuously active in field work, as a research associate in geology with the University California Santa Barbara, and a consultant and volunteer for various government and civic agencies.
A testimonial to the high regard in which he is held by his colleagues was the formation of the Thomas Wilson Dibblee, Jr. Geological Foundation, a nonprofit corporation. This group undertook the task of publishing Tom's many geologic maps, preserving them for their scientific and educational value. In 2002, the Dibblee Geological Foundation merged with the Santa Barbara Natural History Museum to form the Dibblee Geology Center.
Tom remained intimately involved with the map making process through his 93rd birthday in October 2004. Tom's remarkable memory was invaluable in the editing process and he readied about 75 quadrangles this last year for final production.
Tom once said, "I feel driven by a sustained curiosity to see as much of California geology as possible within my lifetime."
In pursuing this vision, he has left a legacy that will benefit us all.
Tom is survived by a sister, Mrs. Joseph A. Donohoe IV (Yvonne Dibblee), and seven nieces and nephews: W. Clasen Hoyt, W. Dibblee Hoyt, Antonia de la Guerra, Joseph A. Donohoe V, Richard Dibblee Donohoe, Anita Dibblee Donohoe and Wilson Dibblee Donohoe.
Contributions in memory of Tom may be sent to the Santa Barbara Museum of Natural History Thomas W. Dibblee Geology Center, 2559 Puesta del Sol Road, Santa Barbara, CA 93105.