Theories on formation of Solar system, Geological time scale and fossils fuels

1. THEORIES ON FORMATION OF SOLAR SYSTEM
History of Earth
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2. GEORGE WOFAN’S HYPOTHESIS
• It was proposed by a French scientist George Wofan
in 1749 AD.
• According to this hypothesis, the earth, along with
other planets and satellites was formed when a
comet moving around the universe stroke the sun
millions of years ago.
• A large amount of matter was thrown out of the sun
during the collision, which further cooled to form
earth and other planets.
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3. Tidal or Gaseous Hypothesis
• James Jeans and Harold Jeffrey in 1917 A.D
• A huge star passed so close to the sun that
its gravity caused a tidal bulge to pull away
from the sun and form the planets when
cooled.
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4. Tidal
Hypothesis
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5. Kant and Laplace’s Nebular
hypothesis
• German philosopher, Immanuel Kant in 1755 AD.
• Later improved by a French astronomer Pierre Simon Laplace
in 1796 AD.
• According to this hypothesis, the solar system developed from
a huge revolving nebula (cloud of gas and interstellar dust).
• When the cloud cooled and contracted, it condensed to form
rings of matter with the central huge mass.
• The central mass became the sun and the outer collection of
gas and dust ultimately gave rise to planets and the satellites
revolving round the sun.
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7. The Geologic Time Scale
Earth’s History
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8. Geologic Time Scale : Scientists have formed a
chronology of Earth’s history based on
evidence from the Earth’s rocks and fossils.
Geologic Time Scale is divided into four
large segments called Eras. The Eras are
subdivided into Periods. The periods are
Further subdivided into epochs.
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10. Present Day
• Present day Earth is in the Holocene epoch, that’s
in the Quaternary period, that’s in the Cenozoic
era.
• So… present day is:
Era= Cenozoic
Period= Quaternary
Epoch= Holocene
**Geologic time has not ended!**
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11. The Diversity of Life throughout
the Geologic Time Scale
Fill in the blank notes 
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12. The geologic time
scale is a record
of the major
events and
diversity of life
forms present in
Earth’s history.
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13. • The geologic time scale began when Earth
was formed and goes on until the present.
• At the end of each era, a mass extinction
occurred. Many kinds of organisms died out.
However, there were other extinctions going
on during each period of geologic time.
• Using the fossil record, paleontologists have
created a picture of the different types of
common organisms in each geologic period.
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14. The Precambrian Era
• 3.4 billion to 543 million years ago. (It accounts
for 87% of the Earth’s history. If the Earth’s history was
compared to a 12 month calendar, the Precambrian Era would
last until the middle of October.)
During this Era, the first cells appeared. They
were bacteria cells that could not use oxygen
and were heterotrophic.
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15. Also in the Precambrian Era: autotrophic
prokaryotes appeared (chemo-synthesizers
and photo-synthesizers).
O2 levels rise & Ozone
forms.
Eventually eukaryotic
cells formed (about
2.1 billion years ago).
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16. By the end of the Precambrian era, multi-
cellular eukaryotic organisms appeared, such
as the invertebrate animals: sponges and
jellyfish.
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17. Paleozoic Era
• This era began with the early invertebrates,
such as trilobites and brachiopods.
• Early vertebrate fish, then arachnids and
insects continued to develop.
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18. • Later came the first amphibians, and near the
era’s end, the reptiles became dominant.
• Early land plants included simple mosses,
ferns, and then cone-bearing plants.
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19. • By the end of the era, seed plants were
common.
• The mass extinction that ended the era caused
most marine invertebrates and amphibians to
disappear.
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20. Mesozoic Era
• Began about 248 million years ago. (If the world’s history is
reduced to a 12 month calendar, it would start on December 10.) It is
divided into three periods: Triassic, Jurassic, and
Cretaceous.
The Mesozoic Era was the “Age of the Dinosaurs”
Mammals appeared and were small and mouse like
at the time. The first birds evolved from a group
dinosaurs. The first flowering plants appeared.
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21. Mesozoic Era
• Reptiles were the dominant animals of this
era, including various dinosaurs.
• Small mammals and birds also appeared.
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22. • Toward the end of the era, flowering plants
appeared and the kinds of mammals
increased.
• The mass extinction that ended the era
caused the dinosaurs to become extinct.
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23. Cenozoic era
Began about 65 million years ago. (About December 26 on
the hypothetical calendar). Mammals began to flourish.
Primates first appeared. Modern humans
appeared perhaps as recently as 200,000 years
ago. (Shortly before midnight on Dec. 31st on the calendar)
This cave painting
was created
By Cro-Magnons
In France about
40,000 yrs ago.
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24. Cenozoic Era
• New mammals appeared while others became
extinct.
• The diversity of life forms increased.
• Flowering plants became most common.
• Humans are also part of the most recent
period of this era.
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28. FOSSIL FUELS
• Coal
• Oil (Petroleum)
• Natural Gas
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29. FORMATION OF FOSSIL FUELS –
SIMPLIFIED
• Burial of organic material millions of years ago
• Reducing conditions – little or no free oxygen
• Reducing conditions preserve organic matter
• Coal and Petroleum diverge from here
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30. COAL FORMATION
• Burial of organic material millions of years ago
• The result was a loss of oxygen and the
reducing conditions preserve organic matter
and forms peat
• When the peat is exposed to high
temperature and pressure, it forms coal.
• There are three main types of coal: anthracite
(95% C), bituminous (50-80% C), and lignite
(50% C).
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32. FORMATION OF
MINERAL OIL AND NATURAL GAS
• Dead algae and plankton accumulated at the
bottom of the ancient seas.
• Accumulation continued, increasing the pressure
and temperature on the underlying layers.
• The result was a loss of oxygen and the formation
of solid, liquid, and gaseous hydrocarbons
• i.e. They were gradually buried by layers of rock
which stopped them rotting
• The liquid and gaseous hydrocarbons moved
upward through the porous rock until reaching an
impermeable layer of rock.
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