Cordilleran Section - 97th Annual Meeting, and Pacific Section, American Association of Petroleum Geologists (April 9-11, 2001)

Paper No. 0
Presentation Time: 2:10 PM


EHRENSPECK, Helmut E., Dibblee, Geological Foundation, 7259 Del Norte Drive, Goleta, CA 93117,

This abstract barely scratches the surface of Tom Dibblee's prodigious career spanning seventy years – so far. Tom Dibblee not only has mapped the geology of about one-fourth of California, but made major contributions to field geology, stratigraphy, structural geology, and tectonics of California. Born in 1911, raised in Santa Barbara and on his family's nearby San Julian Ranch, as a teenager – without formal training in geology – Tom mapped this entire 110-square mile ranch! After a degree in geology from Stanford, 1936, he was hired by Richfield Oil Co. to map the geology of all potential petroleum basins on the West Coast. For 15 years Dibblee mapped vast tracts of California's Transverse and Coast Ranges, as well as coastal Oregon and Washington. On his own time, he then infill-mapped the geology between those oil basins. After Richfield's major oil discovery in the Cuyama basin, based on his mapping, the oil-producing horizon was named the "Dibblee Sand". In 1952, Dibblee joined the USGS western Mojave Desert mapping project, later extended to the central and southern Mojave. Completing over 40 15-minute quadrangles there, Tom next mapped the entire 600-mile long San Andreas fault zone from the Mexican border to northern California and produced over 100 open-file 15-minute quadrangles, which are still being incorporated into a USGS database! "Retiring" in 1978 to Santa Barbara, Tom became research associate at UC Santa Barbara, and volunteer geologic consultant for various agencies. Entirely as volunteer, he produced over 100 7.5-minute quadrangles for the Los Padres National Forest of central coastal California, and over 100 quadrangles, so far, for the Dibblee Geological Foundation. In addition to well over 500 7.5-minute geologic quadrangles Tom has produced, he has established the definitive geologic framework for many areas of California. His prolific bibliography, including over 70 major reports, is on the Dibblee Foundation website: