130 | Great Geologists
appeared in the journal Nature at the
end of 1967. Morgan’s published paper
appeared early in 1968. The papers are
in fact complementary. McKenzie and
Parker focused on the earthquake data,
while Morgan focused on the magnetic
anomalies.
In the late 1960s, McKenzie published
a succession of papers on topics key to
refining the plate tectonics paradigm.
These included convection modelling
and vector analysis of triple junctions.
In 1968, he began work with John
Sclater on surveying the Indian Ocean
with the intent of determining its
entire geological history. The resultant
landmark publication in 1971 eventually
resulted in both authors receiving
Fellowships at the Royal Society.
At this point, McKenzie decided to
move away from plate tectonics, marine
geology, and geophysics, choosing
instead to focus on the behaviour of
fluids below the plates. He studied
cellular convection and motions in the
mantle, using his trademark approach
of identifying the fundamental physical
considerations and testing them in the
simplest possible numerical models.
His work demonstrated that mantle
convection would produce a measurable
gravity signal, thus, testable by
observation.
The early 1970s saw McKenzie
investigating tectonic processes within
plates, aseismic regions that required
a model to explain how extensional
basins form. Since these are basins
where oil and gas are often discovered,
this work (the “McKenzie Model”)
has been of profound importance
to the oil industry. Leading Equinor
geologist Tony Doré described the
resultant 1978 paper (modestly titled
Some Remarks on the Development
of Sedimentary Basins) as the most
important for hydrocarbon exploration in
recent decades. Having collected data in
the Aegean region, McKenzie understood
stretching was taking place not only in
the crust, but in the mantle, too. Fault-
controlled subsidence is followed by
thermal subsidence. Stretching factors
can be calculated along with associated
geothermal history. This is of fundamental
importance in determining the maturity of
source rocks within a basin. has one really good idea when they’re in
their twenties and that is it.” Far from one
brilliant idea, McKenzie has had many,
encompassing plate tectonics, mantle
dynamics, sedimentary basin formation,
melt generation, and planetary geology.
Needless to say, he has received many
honours, including receiving the Copley
Medal of the Royal Society and the
Crafoord Prize of the Royal Swedish
Academy of Sciences.
This work was a natural progression from
another important (and also modestly
titled!) 1967 paper, Some Remarks
on Heat Flow and Gravity Anomalies,
which presented an explanation for the
observations of gravity, bathymetry,
and heat flow at oceanic ridges. The
conceptual leap was to apply the same
physical processes of cooling of the
oceanic lithosphere with time to the post-
rift development of sedimentary basins. This essay has drawn upon information
from the following sources:
McKenzie continues to work at the
Bullard Laboratories in Cambridge,
where he is Emeritus Professor of Earth
Sciences. Most recently, his research
has provided new insights into the
tectonic evolution of Mars and Venus.
He has always been at the forefront of
new technologies and sources of data.
Just as earthquake seismology provided
a key to understanding plate motions
fifty years ago, he now sees continuing
developments in seismology, such as full
waveform inversion, as key to revealing
more of the structure of the earth, from
crust to core.
In a recent interview, he remarked, “I
wondered for a long time whether I was
going to be one of those scientists who
REFERENCES
https://www.mckenziearchive.org/
https://www.newscientist.com/article/
mg23631530-600-dan-mackenzie-the-
man-who-made-earth-move/
Allen, P.A. & Allen, J.R. 2005. Basin
Analysis. Blackwell, 549pp.
Bowler, S. 2017. Fifty years on.
Geoscientist, October 2017, 10-15.
Frankel, H.R. 2012. The Continental Drift
Controversy. Volume 4 Evolution into Plate
Tectonics. Cambridge University Press,
476pp.
McKenzie, D. 2003. Plate tectonics: a
surprising way to start a scientific career.
In: Oreskes, N. (ed.) Plate Tectonics: An
Insiders History of the Modern Theory of
the Earth. Westview Press, 169-190.