Giants of Geology
Charles Lyell
William Smith
James Hutton
Nicola Steno
Robert Hooke
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1900
Nicola Steno – 1638 - 1686
1669-Niels Stensen (Steno) publishes Forerunner, showing diagrammatic
sections of the Tuscany area geology, making the important point that sediments
are deposited in horizontal layers.
Steno’s Laws
Steno's law of superposition:
layers of rock are arranged in a time
sequence, with the oldest on the
bottom and the youngest on the top,
unless later processes disturb this
arrangement. It is Steno's most
famous contribution to geology.
Steno's principle of original
horizontality states that rock layers
form in the horizontal position, and
any deviations from this position are
due to the rocks being disturbed
later.
Steno essentially
abandoned science
after his conversion to
Roman Catholicism in
1667, much to the
dismay of some of his
scientific colleagues. He
was ordained as a priest
in 1675. In 1677, he
became a titular bishop,
and spent the rest of his
life ministering to the
minority Roman Catholic
populations in northern
Germany, Denmark, and
Norway.
Nicola Steno – Fossils
While examining the teeth of the shark,
Steno was struck by their resemblance to
certain stony objects, called glossopetrae or
"tongue stones," that were found in certain
rocks. Ancient authorities, such as the
Roman author Pliny the Elder, had
suggested that these stones fell from the
sky or from the moon. Others were of the
opinion, also going back to ancient times,
that fossils naturally grew in the rocks.
Steno's contemporary Athanasius Kircher,
for example, attributed fossils to a
"lapidifying virtue diffused through the whole
body of the geocosm." Steno, however,
argued that glossopetrae looked like shark
teeth because they were shark teeth, that
had come from the mouths of once-living
sharks, and come to be buried in mud or
sand that was now dry land.
Robert Hooke (1635-1703)
No portrait survives of Robert Hooke. His name is somewhat obscure today, due
in part to the enmity of his famous, influential, and extremely vindictive colleague,
Sir Isaac Newton. Yet Hooke was perhaps the single greatest experimental
scientist of the seventeenth century. His interests knew no bounds, ranging from
physics and astronomy, to chemistry, biology, and geology, to architecture and
naval technology; he collaborated or corresponded with scientists as diverse as
Christian Huygens, Antony van Leeuwenhoek, Christopher Wren, Robert Boyle,
and Isaac Newton. Among other accomplishments, he invented the universal joint,
the iris diaphragm, and an early prototype of the respirator; invented the anchor
escapement and the balance spring, which made more accurate clocks possible;
served as Chief Surveyor and helped rebuild London after the Great Fire of 1666;
worked out the correct theory of combustion; devised an equation describing
elasticity that is still used today ("Hooke's Law"); assisted Robert Boyle in studying
the physics of gases; invented or improved meteorological instruments such as
the barometer, anemometer, and hygrometer; and so on. He was the type of
scientist that was then called a virtuoso -- able to contribute findings of major
importance in any field of science. It is not surprising that he made important
contributions to biology and to paleontology.
Robert Hooke (1635-1703)
Hooke examined fossils with a microscope -the first person to do so -- and noted close
similarities between the structures of petrified
wood and fossil shells on the one hand, and
living wood and living mollusc shells on the
other. In Micrographia he compared a piece of
petrified wood with a piece of rotten oak wood,
and concluded that
“this petrify'd Wood having lain in some place
where it was well soak'd with petrifying water
(that is, such water as is well impregnated with
stony and earthy particles) did by degrees
separate abundance of stony particles from the
permeating water, which stony particles, being
by means of the fluid vehicle convey'd, not
onely into the Microscopical pores. . . but also
into the pores or Interstitia. . . of that part of the
Wood, which through the Microscope, appears
most solid. . . “
Hooke had grasped the cardinal
principle of paleontology -- that
fossils are not "sports of Nature,"
but remains of once-living
organisms that can be used to
help us understand the history of
life. Hooke realized, two and a
half centuries before Darwin, that
the fossil record documents
changes among the organisms
on the planet, and that species
have both appeared and gone
extinct throughout the history of
life on Earth.
Robert Hooke (1635-1703)
1668-Robert Hooke presents a lecture to
the Royal Society claiming that
earthquakes, not the biblical flood, have
caused fossils to be found on
mountaintops and buried in stone.
Perhaps his most famous microscopic
observation was his study of thin slices of
cork, depicted above right. In "Observation
XVIII" of the Micrographia, he wrote:
. . . I could exceedingly plainly perceive it to
be all perforated and porous, much like a
Honey-comb, but that the pores of it were not
regular. . . . these pores, or cells, . . . were
indeed the first microscopical pores I ever
saw, and perhaps, that were ever seen, for I
had not met with any Writer or Person, that
had made any mention of them before this. . .
Hooke had discovered plant cells -- more
precisely, what Hooke saw were the cell walls
in cork tissue. In fact, it was Hooke who
coined the term "cells": the boxlike cells of
cork reminded him of the cells of a
monastery.
William Smith (1769-1839)
Fossils have been long studied as
great curiosities, collected with
great pains, treasured with great
care and at a great expense, and
shown and admired with as much
pleasure as a child's hobby-horse
is shown and admired by himself
and his playfellows, because it is
pretty; and this has been done by
thousands who have never paid
the least regard to that wonderful
order and regularity with which
nature has disposed of these
singular productions, and
assigned to each class its peculiar
stratum. William Smith, notes
written January 5, 1796
William Smith (1769-1839)
Smith observed that the fossils found in a section of
sedimentary rock were always in a certain order from
the bottom to the top of the section. This order of
appearance could also be seen in other rock sections,
even those on the other side of England. As Smith
described it,
. . . each stratum contained organized fossils peculiar
to itself, and might, in cases otherwise doubtful, be
recognized and discriminated from others like it, but in
a different part of the series, by examination of them.
This is a statement of the "principle of faunal
succession."
1815-Relying largely on fossils to identify strata, civil engineer William
Smith publishes a geologic map of England, Wales and part of Scotland,
the largest region so far documented. Four years later, Smith will be
arrested and sent to debtors' prison.
William Smith (1769-1839)
In 1796, Smith was elected to the
agricultural society at Bath, and
began to discuss his ideas with
others who were interested in
rocks and fossils. He began to
write notes and draw up local
geologic maps. Smith was not the
first to make geologic maps, but he
was the first to use fossils as a tool
for mapping rocks by their
stratigraphic order, and not
necessarily by their composition.
Previous mapmakers had
attempted to use the composition
of rocks as indicators of their
position in the stratigraphic
column.
William Smith (1769-1839)
In 1799, Smith's employment with
the canal-building firm came to an
end. Smith then took a series of
engineering jobs in several parts of
Britain, and made a number of side
trips all over England and Wales.
His goal was to produce a complete
geologic map of England and
Wales, using the principles of fossil
succession. Progress was slow, and
money to finance the publication of
such a map was hard to find. Finally,
with the aid of 400 subscribers
underwriting the project, production
of the completed map began in
1812, and in 1815 the map was
finally published.
James Hutton 1726 - 1797
•
In the late 18th century, the educated
world clung to the Neptunian theory of
the earth proposed by Abraham
Gottlob Werner. Known as the father
of geology, James Hutton overturned
the Neptunian orthodoxy and instead
proposed his own Plutonian theory. In
the rocks of Scotland, Hutton found
fingers of granite reaching well into
sedimentary rocks, and saw this as
evidence of subterranean fire and
heat. He also found neatly deposited
layers of sedimentary rocks overlaying
rock layers that were almost vertical,
as shown at right. The lower layers of
rock, he concluded, must have been
deposited eons before, then later
upturned. In them, Hutton saw
evidence of vast expanses of time in
earth's history. (Charles Lyell was
following in Hutton's footsteps when he
wrote his own masterwork in 1830.)
James Hutton 1726 - 1797
•
1794-James Hutton publishes An
Investigation of the Principles of
Knowledge. Buried in the 2,138-page
philosophical tome is a chapter about
variety in nature in which Hutton
anticipates Charles Darwin's theory of
natural selection.
•
1795-James Hutton overturns the
"Neptunian" view of rock formation in
his Theory of the Earth, suggesting
instead that forces of rock creation are
balanced by forces of rock destruction.
Charles Lyell 1797 - 1875
In August 1838 Lyell published the Elements of
Geology, which, from being originally an
expansion of one section of the Principles,
became a standard work on stratigraphical
and palaeontological geology. This book
went through six editions in Lyell's lifetime
(some intermediate editions being styled
Manual of Elementary Geology), and in
1871 a smaller work, the Student's
Elements of Geology, was based upon it.
His third great work, The Antiquity of Man,
appeared in 1863, and ran through three
editions in one year. In this he gave a
general survey of the arguments for man's
early appearance on the earth, derived from
the discoveries of flint implements in postPliocene strata in the Somme valley and
elsewhere; he discussed also the deposits
of the Glacial epoch, and in the same
volume he first gave in his adhesion to
Darwin's theory of the origin of species. A
fourth edition appeared in 1873.
Charles Lyell 1797 - 1875
• “Catastrophism,” was attacked
in 1830 by a British lawyerturned-geologist named
Charles Lyell (1797-1875).
Lyell started his career
studying under the
catastrophist William
Buckland at Oxford. But Lyell
became disenchanted with
Buckland when Buckland tried
to link catastrophism to the
Bible, looking for evidence
that the most recent
catastrophe had actually been
Noah’s flood.
• “Lyell wanted to find a way to
make geology a true science of
its own, built on observation
and not susceptible to wild
speculations or dependent on
the supernatural.
Timeline of Evolutionary Thought
This slide shows the history of
evolutionary thought from 1700
to the present in terms of the
life spans of the principal
figures involved. Note that
some geologists are included
here.
This would be a suitable topic for a
class paper, treating either the
entire timeline shown to the left
or selected parts. The internet
and the library at the back of
the lecture room (Dow 615) are
good resources. The url at the
bottom of the page is for the
Berkeley site from which the
figure is taken. This is a good
site to visit and study, one of
the best in the world and
suitable even for high school
students and laymen.
http://www.ucmp.berkeley.edu/history/evotmline.html