98 | Great Geologists
including the explorer Sven Hedin, the adventurer Roy
Chapman Andrews (the alleged role model for Indiana Jones
and discoverer of dinosaur eggs in Mongolia) and the priest/
paleontologist/philosopher Pierre Theilhard de Chardin. Working
in this fertile atmosphere, Grabau’s research efforts intensified.
As Grabau contemplated the stratigraphy of China and compared
it with his knowledge of other parts of the world, similarities
became apparent to him. Throughout the Paleozoic, there
seemed to be widespread synchronous unconformities and
major synchronous transgressions. This led Grabau to develop
his “Pulsation Theory,” essentially claiming that the Earth had
been subject to episodic global sea-level change throughout its
history. Recognition of transgression and regression was greatly
aided by an understanding of facies diachronism—an idea he had
imported from his dialogue with Johannes Walther.
Eustasy was first termed by Eduard Suess in 1888 and the
concept was much discussed by T.C. Chamberlin, amongst
others, in the early part of the 20th century. Unlike these earlier
workers, Grabau not only discussed how to recognise sea-level
change in the rock record, but presented a biostratigraphically
calibrated global database that could support the synchronicity
of events between locations. He also related his observations to
an explanatory model (heating and expansion, then cooling and
contraction of the ocean floor). It seems that Grabau arrived at
the notion of eustatic sea-level change from a gradual gathering
and synthesis of data, rather than simply setting out to prove the
theory. Sequence stratigraphers today continue to build on the
foundations he laid.
Grabau first presented his ideas at the 1933 International
Geological Congress in Washington, D.C. (his only return to the
country of his birth after moving to China). He subsequently
published four volumes of Palaeozoic Formations in the Light
of the Pulsation Theory, followed by his grand synthesis, The
Rhythm of the Ages, in 1940. At the heart of this work was the
detailing of regular Phanerozoic transgressions and regressions.
But it was also all-encompassing, dealing with everything from
the origin of life on Earth to recent ice ages. Most importantly,
it provided 18 colour paleogeographic reconstructions of how
the Earth had appeared at different episodes in the geological
past. Given that Alfred Wegener’s ideas on continental drift
were still opposed by many geologists, this was a radical step.
Although initially an opponent himself, Grabau used facies and
fossil distribution to suppose, for example, that Greenland, north-
western Europe and north-eastern America had been much
closer together during the Silurian. During the Ordovician and
Silurian, polar ice caps were shown over large parts of Arabia and
North Africa, proof of which was not found until the 1970s.
What is even more remarkable is that this grand synthesis was
prepared at times of extreme difficulty for Grabau. His health
had deteriorated, with arthritis restricting his movements. At the
same time, Peking was occupied by Japanese troops following
the outbreak of hostilities between China and Japan in 1937. As
things worsened in China, with detention once America declared
war on Japan in 1941, Grabau’s health deteriorated even further.
Although he survived the war, he died in 1946 after a short battle
with cancer.
Richard Fortey, in Trilobite! Eyewitness to Evolution, noted
that reverence for wisdom endures in China. “I was taken to
see the grave of Professor Grabau,” he writes. “A Western
paleontologist, who almost singlehandedly introduced modern
geological principles into China in the early years of the twentieth
century. He was, so I was told, ‘a great teacher.’ The Chinese
compliment is such an important one that it is represented by
a special ideogram. It was a simple grave, but obviously and
lovingly tended.”
Amadeus Grabau is not a name that is known to every modern
geologist, but deserves to be for his foresight, mastery of
synthesis and contribution to establishing geology in the world’s
most populous country, China.
REFERENCES
This essay has drawn upon information from the following
sources:
Johnson, M.E. 1992. A.W. Grabau’s embryonic sequence
stratigraphy and eustatic curve. In: Dott, R.H. Jr. (ed.) Eustasy:
The Historical Ups and Downs of a Major Geological Concept.
Geological Society of America Memoir, 180, 43-54.
Mazur, A. 2004. A Romance in Natural History. Garret,
Syracuse, New York. 484pp.
Oldroyd, D.R. 1996. Thinking About the Earth. The Athlone
Press, 410pp.
Pemberton, S. G., Bhattacharya, J. P., MacEachern, J. A.,
& Pemberton, E. A. 2016. Unsung Pioneers of Sequence
Stratigraphy: Eliot Blackwelder, Joseph Barrell, Amadeus
Grabau, John Rich and Harry Wheeler. Stratigraphy, 13, 223-
243.