James Hutton - Jordan School District

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Feb 22, 2014 (3 years and 3 months ago)

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James Hutton

(1726

1797)



James Hutton was
a

Scottish farmer and naturalist and

is known as the

founder of modern geology. He was a great observer of the world around

him. More importantly, he made carefully reasoned geological arguments.

Hutton came to believe that the Earth was perpetually being formed; for

example, molten material is forced up into mountains, eroded, and then eroded
sediments are washed away. He recognized that the history of the Earth could be
determined by understandi
ng how processes such as erosion and sedimentation work
in the present day. His ideas and approach to studying the Earth established geology as
a proper science.

In the late eighteenth century, when Hutton was carefully examining the rocks, it was
generall
y believed that Earth had come into creation only aro
und six thousand years
earlier
and that fossils were the remains of animals that had perished during the
Biblical flood. As for the structure of the Earth, “natural philosophers” agreed that
much bedrock

consisted of long, parallel layers which occurred at various angles, and
that sediments deposited by water were compressed to form stone. Hutton perceived
that this sedimentation takes place so slowly that even the oldest rocks are made up
of, in his word
s, “materials furnished from the ruins of former continents.” The reverse
process occurs when rock exposed to the atmosphere erodes and decays. He called
this coupling of destruction and renewal the “great geological cycle,” and realized that
it had been c
ompleted innumerable times.

Hutton came to his chosen field by quite a roundabout route. Born in Edinburgh in
1726, he studied medicine and chemistry at the Universities of Edinburgh, Paris, and
Leiden, in the Netherlands, and then spent fourteen years run
ning two small family
farms. It was farming that gave rise to Hutton’s obsession with how the land could hold
its own against the destructive forces of wind and weather he saw at work around him.
Hutton began to devote his scientific knowledge, his philoso
phical turn of mind, and
his extraordinary powers of observation to a subject that had only recently acquired a
name: geology.

Around 1768 he moved to Edinburgh, where a visitor a few years later described his
study as “so full of fossils and chemical appa
ratus that there is hardly room to sit
down.” In a paper presented in 1788 before the Royal Society of Edinburgh, a newly
-
founded scientific organization, Hutton described a universe very different from the
Biblical cosmos: one formed by a continuous cycle

in which rocks and soil are washed
into the sea, compacted into bedrock, forced up to the surface by volcanic processes,
and eventually worn away into sediment once again. “The result, therefore, of this
physical enquiry,” Hutton concluded, “is that we fi
nd no vestige of a beginning, no
prospect of an end.” Relying on the same methods as do modern field geologists,
Hutton cited as evidence a cliff at nearby Siccar Point, where the juxtaposition of
vertical layers of gray shale and overlying horizontal laye
rs of red sandstone could only
be explained by the action of stupendous forces over vast periods of time. There
Hutton realized that the sediments now represented by the gray shale had, after
deposition, been uplifted, tilted, eroded away, and then covered

by an ocean, from
which the red sandstone was then deposited. The boundary between the two rock
types at Siccar Point is now called the Hutton Unconformity.

The fundamental force, theorized Hutton, was subterranean heat, as evidenced by the
existence of h
ot springs and volcanoes. From his detailed observations of rock
formations in Scotland and elsewhere in the British Isles, Hutton shrewdly inferred that
high pressures and temperatures deep within the Earth would cause the chemical
reactions that created
formations of basalt, granite, and mineral veins. He also
proposed that internal heat causes the crust to warm and expand, resulting in the
upheavals that form mountains. The same process causes rock stratifications to tilt,
fold and deform, as exemplified

by the Siccar Point rocks.

Another of Hutton’s key concepts was the Theory of Uniformitarianism. This was the
belief that geological forces at work in the present day

barely noticeable to the
human eye, yet immense in their impact

are the same as those th
at operated in the
past. This means that the rates at which processes such as erosion or sedimentation
occur today are similar to past rates, making it possible to estimate the times it took to
deposit a sandstone, for example, of a given thickness. It bec
ame evident from such
analysis that enormous lengths of time were required to account for the thicknesses of
exposed rock layers. Uniformitarianism is one of the fundamental principles of earth
science. Hutton’s theories amounted to a frontal attack on a p
opular contemporary
school of thought called catastrophism: the belief that only natural catastrophes, such
as the Great Flood, could account for the form and nature of a 6,000
-
year
-
old Earth.
The great age of Earth was the first revolutionary concept to e
merge from the new
science of geology.

The effect that this portrait of an ancient, dynamic planet had on the thinkers who
followed in the next century was profound. Charles Darwin, for example, was well
acquainted with Hutton’s ideas, which provided a fra
mework for the eons required by
the biological evolution he observed in the fossil record. English geologist Sir Charles
Lyell, who was born the year Hutton died and whose influential book Principles of
Geology won wide acceptance for the Theory of Uniform
itarianism, wrote, “The
imagination was first fatigued and overpowered by endeavouring to conceive the
immensity of time required for the annihilation of whole continents by so insensible a
process.

” The “ideas of sublimity” awakened by this “plan of such

infinite extent,” as
Lyell referred to it, inspired not only Hutton’s contemporaries, but generations of
geologists to come.









Hutton
Unconformity: