An Idea to Pursue - Four Revolutions in the Earth Sciences - page 56

The sine qua non of Taylor's thinking was the idea that the Moon is a comet
captured by the Earth's gravity. He proposed that the capture had created new tidal
forces that had speeded up the Earth's rotation, which in turn caused the continents
to slide away from the poles toward the equator. The sliding continents had piled
up to create the mountain ranges.
In 1910, Taylor published his continental-sliding theory in a forty-seven-page
paper. 12 The article did not mention the Moon but, as the title indicated, focused
on the “Bearing of the Tertiary Mountain Belt on the Origin of the Earth's Plan.”
Taylor spent much of the article paying homage to Suess, of whom he wrote, “It
seems certain that no man living has ranged so widely over the fields of geology
for the entire Earth as Eduard Suess.” 13 But in the end, Taylor had to reject his
idol's contraction theory.
The deforming forces that Taylor envisioned had “operated to flatten the earth
at the poles” (219). This changed the Earth from a perfect sphere to an oblate
spheroid, and that in turn had moved the Earth's center of gravity “toward the
other pole” (220). This led to what Taylor called “general crustal creep” toward the
equator from the north and south poles.
Although Taylor's model turned out to be wrong, he did get some things right.
He noted, for example, that the Himalayas owe their origin to a collision between
India and the Asian continent. He also called attention to “one of the most re-
markable and suggestive objects on the globe . . . the mid-Atlantic ridge,” already
known from Sir John Murray's bathymetric chart, which Taylor reproduced. He
wrote that “the great westward bulge of Africa north of the equator appears to
fit very closely into the westward bend of the mid-Atlantic ridge, suggesting that
Africa has drifted eastward from that position” (217, italics added). The discov-
ery of the true dimensions and location of the Mid-Atlantic Ridge some forty-five
years later would help resurrect Wegener's theory, though not Taylor's.
Taylor's observations raise the question of whether he deserves partial credit for
thetheoryofcontinental drift.Indeed,inearlier yearsitwascommon toreadofthe
“Taylor-Wegener” hypothesis. But this interpretation has not held up, most histor-
ians of geology having concluded that Wegener developed his ideas independently
of Taylor, as Wegener said he had, and developed them much more fully. 14
Anthony Hallam sagely compared Taylor and Wegener to Alfred Wallace and
Charles Darwin. In each pair, the two members independently came up with the
same insight, but only one developed and expanded the idea, and that one de-
servedly got the lion's share of the credit. 15