Great Geologists | 115
VINE’S EARLY INFLUENCES
Fred Vine was born in Chiswick in west London in 1939. In April 1955, at the age of 15, when he was on his Easter holiday
and studying for upcoming exams, he opened a textbook on geography and came across a diagram showing the approximate
fit of the Atlantic coastlines of South America and Africa. According to Vine, “In the text, it stated that although it had been
suggested on the basis of this fit that these continents were once part of a supercontinent that subsequently split and drifted
apart to form the South Atlantic Ocean, geologists had no idea whether there was any truth in this hypothesis. I was struck
at once both by the boldness of the idea that seemingly stable continents might have drifted across the face of the Earth in
the past, and by the fact that we did not know whether this had occurred. It seemed to me that one could hardly conduct any
meaningful study of the history of the Earth until one had resolved this issue. Surely there must be some way of proving or
disproving the concept of continental drift.” It would come to pass that it would be Vine, himself, who helped supply the proof.
In 1959, Vine began his studies in natural sciences at St. John’s College, Cambridge. In addition to mathematics and physics,
he opted to study geology. Cambridge was a university with strength in geophysics and with some staff, like Brian Harland,
positively inclined towards continental drift. In January 1962, the university hosted the 10th Inter-University Geological
Congress where the guest speaker Harry Hess outlined his ideas on seafloor spreading. The lecture had a profound effect
on Vine, who summarised much of Hess’s work in his own talk to the student geological society, the Sedgwick Club, later
that year humorously entitled “HypothHESSes”. Also in 1962, he attended a lecture by the doyen of British paleomagnetists,
Patrick (later Lord) Blackett, for whom continental drift was axiomatic, given the evidence from paleomagnetic data on apparent
polar wander and paleolatitude.
MAGNETIC REVERSALS AND SEAFLOOR SPREADING
It is not surprising then, that at the outset of his PhD in the autumn of 1962, Vine was contemplating his research topic through
the lens of continental drift. That topic was to review published magnetic surveys and traverses at sea, and the methods
used in interpreting them. He began by evaluating the magnetic survey data gathered in 1962 over the Carlsberg Ridge, an
oceanic ridge in the Indian Ocean. Vine has admitted he approached this work with seafloor spreading in mind. He “was
particularly looking for some record of drift and spreading.” With spectacular insight, he rapidly concluded that the patterns in
magnetisation in the vicinity of the ridge were due to alternations of reversed and normal magnetisation of the rocks forming
the ridge and the ocean floor. These patterns were not local. They were the result of reversals of the Earth’s magnetic field.
This theory was neatly linked to seafloor spreading. As the emergent seafloor cooled, it acquired a magnetisation in keeping
with the geomagnetic field prevailing at the time. Later, as this crust was displaced by new material, if the Earth’s magnetic
field reversed, the newer material would be magnetised in the opposite direction to the adjacent, older crust. This led to
repeated alternations and, thus, the magnetic anomaly (zebra) stripes that had been observed in marine palaeomagnetic
records since the 1950s.
Vine reported his ideas to his supervisor, Matthews, who arranged for publication of a short paper in the journal Nature in
1963 — Magnetic anomalies over ocean ridges. Despite the importance of this paper, it took time for its conclusions and its
significance to be accepted by the scientific community at large. There were a number of doubts. Firstly, the idea of episodic
reversals of magnetic polarity through time was not accepted by everyone. Moreover, Vine and Matthews had combined this
with the controversial notion of seafloor spreading.
TESTING THE HYPOTHESIS
Support for the Vine-Matthews hypothesis came when Harry Hess and the great Canadian geologist, Tuzo Wilson, came to
Cambridge as visiting researchers in 1965. They encouraged Vine to consider that the hypothesis implied a uniform rate of
spreading, which could be tested by dating the crust. It also implied that anomalies should be symmetrical on either side of an
ocean ridge.