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EARTH’S DRIFTING
CONTINENTS ARE
GIANT PIECES IN AN
EVER-CHANGING JIGSAW
ALFRED WEGENER (1880–1930)
IN CONTEXT
BRANCH
Earth scienceBEFORE
1858 Antonio Snider-Pellegrini
makes a map of the Americas
connected to Europe and
Africa, to account for identical
fossils found on opposite sides
of the Atlantic Ocean.1872 French geographer
Élisée Reclus proposes that
motion of the continents
caused the formation of the
oceans and mountain ranges.1885 Eduard Suess suggests
the southern continents were
once linked by land bridges.AFTER
1944 British geographer
Arthur Holmes proposes
convection currents in Earth’s
mantle as the mechanism that
moves the crust at the surface.1960 American geologist
Harry Hess proposes that
seafloor spreading pushes the
continents apart.I
n 1912, German meteorologist
Alfred Wegener combined
several strands of evidence to
put forward a theory of continental
drift, which suggested that Earth’s
continents were once connected but
moved apart over millions of years.
Scientists only accepted his theory
once they had figured out what
made such vast landmasses move.
Looking at the first maps of the
New World and Africa, Francis
Bacon had noted, in 1620, that theeastern coasts of the Americas are
roughly parallel with the western
coasts of Europe and Africa. This
led scientists to speculate that these
landmasses were once connected,
challenging conventional notions of
a solid, unchanging planet.
In 1858, Paris-based geographer
Antonio Snider-Pellegrini showed
that similar plant fossils had been
found on either side of the Atlantic,
dating back to the Carboniferous
period, 359–299 million years ago.South America’s
east coast fits
Africa’s west coast
like two giant
jigsaw pieces.Earth’s drifting continents are giant pieces
in an ever-changing jigsaw.The continents must once have formed a single landmass.Similar plant and
animal fossils
are found in South
America and
in Africa.Matching rock
formations
are found in
South America
and in Africa.