Preston Cloud; Studied ‘Biogeology’ of Cosmos

Preston Cloud, an internationally recognized scientist whose research ranged from the evolution of life on Earth to the study of moon rocks, has died at his Santa Barbara home at age 78.

A spokesman for UC Santa Barbara, where Cloud was a professor emeritus, said the geologist and environmentalist died Jan. 16. His family said he had been battling pneumonia.

Cloud coined the term “biogeologist” to describe his specialty. His interests ranged beyond traditional geology into biology, chemistry and the cosmos, which he melded into a 50-year, multifaceted study of the history of the Earth.

Last October, Andrew Knoll of Harvard University, writing in a volume of the American Journal of Science dedicated to Cloud, said Cloud’s “influence on 20th-Century geology and paleontology is incalculable. . . . (His) enduring contribution has been to establish the very way in which we think about early evolution.”


The most recent of Cloud’s hundreds of papers and books was “Oasis in Space: Earth History From the Beginning,” published in 1987.

A Times reviewer found it “a monumental work of synthesis of the natural history of the Earth.”

Cloud did his undergraduate work at George Washington University in Washington and earned his doctorate in geology at Yale. He taught at Harvard, the University of Minnesota and UCLA before coming to Santa Barbara.

In 1969, Cloud was one of the geologists who traveled to Houston to pick up samples of the first moon rocks brought to Earth and helped establish that the moon was devoid of life in any form.


Cloud’s research led him to conclude in his final book that “we are made of star stuff, processed through supernovae, concentrated from the contracting solar nebula, spun into biochemical aggregates with a difference, and graced, during our tenure here, by the ability to imagine, to conceptualize, to hypothesize, to create science, poetry, music and works of art and technology.”

His survivors include his wife, Janice, two daughters, a son, three stepchildren and three sisters.