Download The Industrial Revolution

History of Geology
The industrial revolution and the birth
of Geology
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Necessity of Geology for mining and industry
Beginning of systematic study of mountains
and geological mapping
Beginning of systematic dating and the first
geological time scale
The challenge of dating the earth and its
various formation
The advances in technology allow advances in
Sciences, especially Geology
The Industrial Revolution
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With the Industrial
Revolution new technologies arose and developed
Newly industrialized
countries start to use new
energies like coal
The Industrial Revolution
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With the Industrial
Revolution new technologies arose and developed
Newly industrialized
countries start to use new
energies like coal
As the need for metals
and coal increase, mining
and prospecting for ore
deposit expand
Geological studies of
mountains for finding new
mining places
The Industrial Revolution
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Geological knowledge is
necessary to understand
ore and coal deposit and
storage
Geological observations
in plains and mountains
allow to understand the
relationship between ore
and the nature of the host
Geological studies allow
to know where open new
mines and how exploit
them
The Industrial Revolution
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The first geological maps
are realised in France and
England between 1814
and 1841
The Industrial Revolution
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The first geological maps
are realised in France and
England between 1814
and 1841
They aim to classify the
various rocks formations
and to localise possible
mining sites
Other countries like
Germany and Italy follow
and a great geological
mapping campaign starts
in Europe
The Industrial Revolution
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The mapping and classification of the rock
formations lead the early
geologist to group and to
try a dating of the rocks
they observe
The questions of the type
of each rock, its origin
and the importance of
fossils rose from this
global mapping
Stratigraphy is about to
arise
The Industrial Revolution
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For Abraham Gottlob
Werner and the
Neptunian, the earth is
progressively loosing its
energy since its birth
Mountains are the result
of sedimentation over the
“hills” of the primitive
globe
Oceans level is constantly
decreasing and the water
is loosing its mineral
charge by precipitation
The Industrial Revolution
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Werner and his students
started to systematically
study the mountains on
the earth
They made the first great
classification of
sedimentary rocks using
their content in fossils
They realised the first
relative geological time
scale using the sedimentary rocks and their
superposition order
The Industrial Revolution
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Werner's method had
some weakness
He did not recognize the
existence of plutonic and
volcanic rocks and thought
that the basalt was a
sedimentary rock
He thought that the granite
was only “primitive”
He could not explain the
presence of basalt or
granite at various level of
his “geological time scale”
The Industrial Revolution
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Werner's method had
some weakness
He did not recognize the
existence of plutonic and
volcanic rocks and thought
that the basalt was a
sedimentary rock
He thought that the granite
was only “primitive”
He could not explain the
cross-cutting relationships
between volcanic and
sedimentary rocks
The Industrial Revolution
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James Hutton demonstrated the magmatic origin
of basalts & granites
He was inspired by steam
engines to model the
formation of mountains
and its energy source
The rising of mountains
would be accompanied
by folding of the
sedimentary layers and
thrust faulting leading to
discordant contacts
The Industrial Revolution
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The weakness of
Hutton's model is to
apply the same universal
processes to the whole
earth and neglecting
regional history
The source for the earth
internal heat would be
the combustion of coals
within the earth with an
eternal cycle of production by fossilisation of
trees and combustion
The Industrial Revolution
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After Werner & Hutton,
their models were both
combined to make a
better representation of
the earth
Local sedimentation or
magmatic events can
explain regional geology
The integrated approach
combining the classification of fossils and the
determination of the
nature of rock lead to the
birth of Stratigraphy
The Industrial Revolution
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At that time, in the
geological world, two
great theories were in
conflict
The Uniformitarianism
assumes that the same
natural law and processes
operated in the past times
and in the present time
It has included the
gradualistic concept that
“the present is the key to
the past”
The Industrial Revolution
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Uniformitarianism has
been a key principle of
geology
It supposes that the law of
nature are constant across
time and space
Past and present causes
are all of the same kind,
have the same energy, and
produce the same effects.
The same processes led to
the same geological
formations through time
The Industrial Revolution
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At that time, in the
geological world, two great
theories were in conflict
The Catastrophism
assumes that the earth
changes by sudden, shortlived and violent events
It supposes that the
surface of the earth totally
changes during short
catastrophic events and
that these events are not
to be reproduced
The Industrial Revolution
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Catastrophism directly
derives from the
creationist view of the
earth suggesting that the
earth was created in a
relatively short time and
that disasters destroyed a
part of the primitive earth
E.g. Deluge myth
This theory was supported
th
by geologists till the 20
century as the best way to
explain mass extinctions
The Industrial Revolution
Uniformitarianism against Catastrophism
➢ Uniformitarianism suggests slow and continuous
processes all along the earth history, the earth is
relatively stable and the disappeared old species
could live in the present day earth
➢ Uniformitarianism well explains the succession of
sedimentary layers, the presence of old and recent
rocks of similar nature (e.g. old and recent granites)
➢ Uniformitarianism cannot explain tectonic
movements, thrusting and the formation and
extent of great mountain chains
➢ This theory also cannot explain the mass
extinctions which are more and more documented
The Industrial Revolution
Uniformitarianism against Catastrophism
➢ Catastrophism suggests sudden and radical
changes at some definite points of the earth
history, the climate and morphology of the earth
are totally different from the past
➢ Catastrophism explains the formation of
mountains by collapse of old sedimentary layers
➢ Catastrophism well explains the mass extinctions
of the geological time
➢ This theory does not account for slow and
progressive sedimentation and for continuous
magmatic activity
The Industrial Revolution
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The two theories of
Catastrophism and
Uniformitarianism will be
combined in a sequential
model to explain various
processes of the earth
The uprising of mountains,
sedimentation and
fossilisation may be
related processes
Élie de Beaumont (17981874) first suggested the
idea of regional orogeny
The Industrial Revolution
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The uprising of mountain
chains would be at the
origin of great changes in
the sea configuration
The changes in the limits
and configuration of the
sea would lead to mass
extinction
Between orogenic events,
the earth is stable and the
landscape does not change
except by erosion &
sedimentation
The Industrial Revolution
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The mechanism explaining
orogeny and the sea
movements was supposed
to be the earth cooling
Mining and studies in the
depths of the mines led to
the discovery of the
geothermal gradient in
1827
The earth subsoil is hotter
than the surface and the
temperature increase by
3.3°C every 100 m
The Industrial Revolution
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The geothermal gradient
expresses the cooling of
the earth
The experimentation
during 18th and 19th centuries showed that most
cooling bodies contract
The earth, by cooling,
would contract and the
outer hard layer would
fold and/or collapse
leading to the formation
of mountains and seas
The Industrial Revolution
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From this point several
data could be used for
dating of the earth
Kelvin (1824-1907) made a
calculation of the age of
the earth based on the
thermal conduction of
rocks, the geothermal
gradient and the earth
cooling
He calculated an age
between 24 and 400
million years
The Industrial Revolution
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Sediments and fossils
specialists recognised that
in the present days, only
few millimetres of
sediments may
accumulate every year
Sedimentary sequences of
several hundreds of metres
would require several
million of years to form
Dating based on sedimentary rates is not precise
but gives a minimum age
The oldest Rock on Earth
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Gneiss ( 片麻岩 ): metamorphic rock
composed of plagioclase, mica and amphibole
Amphibolite ( 角閃岩 ): metamorphic rock
composed of plagioclase and amphibole
Granulite ( グラニュライト ): metamorphic
rock composed of plagioclase, quartz and
garnet
Plagioclase ( 斜長石 ): mineral rich in Ca and
Al
Amphibole ( 角閃石 ): mineral rich in Mg and
Fe
Mica ( 雲母 ): mineral rich in K and Mg
The oldest Rock on Earth
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Sedimentary rocks, at ~800°C would melt into
a liquid of granitic composition
At high pressure and temperature, sedimentary
rocks would recrystallise, possibly partially melt
and transform into a gneiss
Sedimentary rocks and granites have the same
chemical composition but different
mineralogical compositions
Dating of a granite or a gneiss usually gives
the age of its last melting
Gneisses & granites contains zircons (mineral
rich in Zr and Hf)
The oldest Rock on Earth
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Zircon is one of the strongest mineral on earth.
It resists to alteration and remelting at 800900°C
When gneisses or granites are “reset” by
melting, only the zircon can give the original
age of the rock (dating on zircon)
Zircons are rich in U and Hf, their dating is
relatively technically easy
Gneisses and granites were thought to be the
most primitive and the oldest rocks on the
earth
The firsts radiogenic dating of the earth were
realised with these rocks
The Industrial Revolution
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The discovery in 1896 by
Henri Becquerel (18521908) of the radioactivity
allow to understand that
the earth is much older
than only 400 million years
In 1913, Arthur Holmes
(1890-1965) was the first to
calculate a radiogenic age
for the earth
He found an age of 1.4
billon years based on the
analysis of some archean
granits
The Industrial Revolution
The Industrial Revolution
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Progressive invention of
the microscope during the
th
17 century in parallel with
advances in optical
sciences
Discovery of radioactivity
and its measurement
The Industrial Revolution
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Progressive invention of
the microscope during the
th
17 century in parallel with
advances in optical
sciences
Discovery of radioactivity
and its measurement
Invention of the steam
engine and beginning of
fast travel
Discovery and development of new energy
sources (oil, coal)