Barrow, Leonidas Theodore (1895–1978)

By: Samuel P. Ellison, Jr.

Type: Biography

Published: November 1, 1994

Updated: September 6, 2016

Leonidas Theodore (Slim) Barrow, petroleum geologist, the son of Thomas Heskew and Sarah (Graves) Barrow, was born on June 16, 1895, in Manor, Texas. He was educated in the public schools of Austin and entered the University of Texas in 1917, but in 1918 he left the university to join the Signal Corps of the United States Army. He returned to the university upon his military discharge in 1919 and was awarded the bachelor's degree in geology in 1921. During his undergraduate days he played on the Longhorn football and basketball teams, where he earned his nickname. He received his master's degree in 1923 and served as instructor in geology at the University of Texas from 1921 to 1924. In 1923 he married Laura Thomson, a geology student at the university.

Barrow joined the Humble Oil and Refining Company (see EXXON COMPANY, U.S.A.) as field geologist in San Antonio in 1924. He did surface geologic mapping in Caldwell and Guadalupe counties, where his company discovered the Salt Flat and Darst Creek oilfields. He recognized the igneous origin of the material that makes up the pay section of the Lytton Springs oilfield in Caldwell County. By 1929 he was made chief geologist for Humble in Houston. There he became associated with Wallace E. Pratt, a member of the board of directors of the company. Pratt and Barrow, working together, established the highest type of business and professional ethics in the petroleum industry. Barrow was promoted to the board of directors of his company in 1937, to vice president in 1938, and to chairman of the board in 1948. He retired in 1955.

Barrow and his wife aided the University of Texas by helping to organize and donating to the Geology Foundation in 1952. The foundation provides loans for needy students, travel funds for teachers, scholarship and fellowship funds, library funds, and endowments establishing named professorships and chairs in geological sciences. Barrow served on the Geology Foundation Council from 1957 to 1963 and was elected a lifetime honorary member in 1964. He was also a member of the American Association of Petroleum Geologists, the Society of Petroleum Engineers, and the Geophysical Union, as well as a fellow of the Geological Society of America. He and his wife were the founders of the Wallace E. Pratt Publication fund of the American Association of Petroleum Geologists. They also made important contributions to many other geological, charitable, and church organizations. Barrow died in Houston on March 4, 1978.

M. J. Davis, "Memorial to L. T. Barrow," Bulletin of the American Association of Petroleum Geologists 62 (October 1978). Samuel P. Ellison, Jr., "Memorial to Leonidas Theodore Barrow," Geological Society of America Memorials 10 (1980).

  • Oil and Gas Industry
  • Science
  • Geologists and Geophysicists
Time Periods:
  • Texas in the 1920s
  • Great Depression
  • Texas Post World War II
  • Houston
  • Upper Gulf Coast
  • East Texas

The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this entry.

Samuel P. Ellison, Jr., “Barrow, Leonidas Theodore,” Handbook of Texas Online, accessed May 25, 2022,

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November 1, 1994
September 6, 2016

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