PLATE TECTONICS

Firsthand reports of the birth of modern plate tectonics, the once heretical, now governing theory of how the earth works.

Since at least the 16th century, writes historian of science and geologist Oreskes (History/Univ. of California, San Diego), earth scientists have observed “the jigsaw-puzzle fit of the continental edges,” whereby Africa nestles neatly into South America, western North America into eastern Asia. Theories of continental drift and crustal contraction accounted for some geomorphological phenomena, but only in the 1960s did scientists begin to accrue solid evidence for how such things actually worked—with most of such evidence gathered on the hitherto inaccessible floors of the deep oceans. Strikingly, the majority of those scientists, Oreskes observes, were attached to only four institutions worldwide—Cambridge University, the Columbia University Lamont Geological Observatory, Princeton University, and the University of California Scripps Institution of Oceanography. (Soviet scientists, hampered by an officially endorsed theory emphasizing “vertical tectonics,” would join the revolution only much later.) Though many of the principal theoreticians have since died, Oreskes gathers testimony from some important participants, among them Ron Mason (who analyzed the geomagnetic patterns on the ocean floor that provided “the first step in what eventually became a new global theory of the earth”), Frederick Vine (whose research provided proof of geologist Tuzo Wilson’s theory of the existence of the Juan de Fuca plate), Neil Opdyke (who studied reversals of the earth’s geomagnetic field), and David Sandwell (whose work in radio altimetry helped map the planet’s crustal structure). Most of their reminiscences, along with those of 14 other contributors, are written at a level accessible to nonspecialist readers, and the authors’ enthusiasm for the study of the earth and its ways overcomes the occasional thickets of geological terminology.

A useful addition to the history-of-science literature, emphasizing the importance of scholarly communication and verification.