Develop technical competence in basic principles of soil mechanics and fundamentals of application in engineering practice. (Outcomes b, e, k) Ability to list the salient engineering properties of soils and their characteristics and describe the factors which control these properties. (Outcomes c)

1. Essential Question
• WHAT IS THE GEOLOGIC
TIME SCALE?

2. Standard
• Standard 8.E.6 The student will
demonstrate an understanding of Earth’s
geologic history and its diversity of life
over time.

3. The Geological Time Scale

4. What is the Earth’s time scale?
• The geologic time scale is a record of the
major events and diversity of life forms
present in Earth’s history. The geologic
time scale began when Earth was formed
and goes on until the present. It divides
Earth’s long history into units of time.
• Scientists developed the time scale by
studying rock layers and fossils world
wide.

5. What about the Geologic Time
Scale?
• Precambrian is the name given to the
earliest span of time in Earth history.

6. Reading and About the
geologic time scale divisions
• The geologic history of the Earth is broken
up into hierarchical chunks of time. From
largest to smallest, this hierarchy
includes EONS, ERAS, PERIODS, AND
EPOCHS. All of these are displayed in the
portion of the geologic time scale shown
below.

7. • The geologic time scale divides Earth’s long
history into units of time: There are 4 major
subdivisions of Geologic Time
• Eons which subdivides into eras
• Eras which subdivides into periods
• Periods which subdivides into epochs
Eons
Eras
Periods
Epochs
BIG E = E + P = EP

8. • These subdivisions are based on large
scale events in Earth’s history that are
identified in the fossil record and rock
layers.

9. • The Phanerozoic Eon is subdivided into
three major divisions: the PALEOZOIC,
MESOZOIC, AND CENOZOIC Eras. The
"-zoic" suffix comes from the root "zoo,"
which means animal.
•
• Cen-" means __RECENT_, "Meso-"
means _MIDDLE__, and "Paleo-" means
___ANCIENT_.

10. What is the present day or modern day Eon,
Era, Period, and EPOCH we live in?
•EON: PHANEROZOIC
•ERA: CENOZOIC
•PERIOD: QUARTNERY
•EPOCH: HOLOCENE

11. • Cambrian being the first period is
important.
• With a more complete fossil record
available, the periods of the Cenozoic era
are subdivided further into epochs.
• Geologic time has not ended.

12. • At the end of each era a major mass
extinction occurred, many kinds of organisms
died out, although there were other
extinctions going on during each period of
geologic time.
• The layers of rock on Earth serve as
evidence when identifying the geologic time
scale. Using the fossil record, paleontologists
(scientist who studies fossils) have created
a picture of the different types of common
organisms in each geologic period.

13. Check Point
1. Name the divisions in order from the largest to the
smallest?
2. Name the divisions in order from the smallest to the
largest?
3. Name the 3 Eras.
4. What is the present day or modern day Eon, Era, Period,
and EPOCH we live in?
5. Triassic is a _________
6. Precambrian has ____ Eons.
7. Name the 1st period and which Era do it belong to?
8. _______________ is the only Era that contains epochs.
9. All Eras end with the suffix _____________.
10. All epochs end with the suffix _________________.
11. Has the Geologic time ended? How do you know?

14. Different types of Geologic Time
Scale

18. Major information found on
the geologic time scale
includes:
• During the first billion years of Earth’s
history, the land was covered with
volcanoes. Over the next 3 billion years,
simple life-forms began to live in oceans.

19. •TAKING A LOOK
AT EACH DIVISION

20. The Precambrian
Time!

21. The Precambrian Record

22. EARTH DURING
PRECAMBRIAN TIME

23. TIMEFRAME
• 4.6 billion to 544 million years ago

24. IMPORTANT FACTS
- Earliest part of Earth’s history
- covered approximately 88% of Earth’s history which
makes it the longest part of Earth’s history.
•Earth formed
• Life arose
• First tectonic plates arose and began to move
• Atmosphere became enriched in oxygen
•Is known as a Supereon because it is divided into 3 eons
(Proterozoic, Achaean, and Hadean)

25. Precambrian Time

26. Animals (Biological) Features
•Most organisms had soft bodies
which looked like modern jellyfish
and worms
Many Precambrian fossils are
Trace fossils.

27. 630 MYA Precambrian Time
• Multicellular organisms evolve with soft bodies
Species include:
jelly fish; coral
stalks;
segmented
worms; algae

28. Animals (Biological) Features
Land (Geological) Features
• Primarily covered by the ocean
• Had a lot of volcanic activity

29. MASS EXTINCTION
• MASS EXTINCTION IS THE EVENT
THAT ENDED PRECAMBRIAN TIME.
• * glaciation event
• Precambrian time were marked by a
prolonged global ice age. This may
have led to widespread extinctions.

30. Check Point
1. Precambrian Time was mostly covered by what?
2. Precambrian Time was the ______ part of the Earth’s
history
3. What types of animals lived during Precambrian time?
4. Precambrian Time is known as a ________ because it
contains 3 eons.
5. What caused the mass extinction of Precambrian
Time?

32. PALEOZOIC ERA
• KNOWN AS THE AGE OF FISH OR
TRILOBITES

34. Paleozoic Era Timeframe
• 544 million to 248 million years ago

35. Paleozoic Era
Life starts in the seas and moves onto land
Six periods:
Cambrian
Ordovician
Silurian
Devonian
Carboniferous-2 periods included
Permian

36. Important Facts
• Pangea was forming during this era as far as
coming together
• Cambrian being the first period is important.
• The Cambrian Explosion was a time where
there was a relatively rapid appearance of
most major animal phyla as evidenced by the
fossil record.

37. Cambrian “explosion”
For reasons unclear, 13 million
years after the start of the
Cambrian (so 530 my), there
was a tremendous
diversification of marine life
forms, some of which have
never been reproduced.
Cambrian Explosion –
Most major animal
phyla are found in the
fossil record (mostly
aquatic invertebrates
with exoskeletons).

38. Animals (Biological) Features
• Began with the early invertebrates, such as trilobites
and brachiopods
WHAT FIRST APPEARED:
1. Trilobites
2. fish
3. arachnids and insects
4. first amphibians
5. near the era’s end the reptiles became dominant.
WHAT BECAME DOMINANT:
1. Trilobites
2. Fish

39. Trilobites
• Lived in Earth’s ancient seas
• Extinct before the dinosaurs
came into existence
• Cambrian Period is know as
the “Age of the Trilobites”
(put in on table)

40. Brachiopods
• Marine animals that resemble clams.

41. Early Fish
Early fish did not have jaws.
Some species of sharks
were in existence at this
time.

42. Frilled Shark that was found in Japan in January 2007. This shark was
considered a “living fossil”

43. Land (Geological) Features
• During most of the Era, warm shallow seas
covered much of the planet.
WHAT FIRST APPEARED:
1. Simple mosses
2. Ferns
3. Cone-bearing plants
4. Seed plants

44. Early Land Plants
Cone bearing plants
Ferns
Mosses

45. HOW EARTH LOOKED
DURING THE PALEOZOIC
ERA

47. Mass Extinction
• The mass extinction that ended the era caused
most marine invertebrates as well as amphibians
to disappear.
• About 95 percent of marine species and 70 percent of
land animals were wiped out after the Permian mass
extinction.
• It is suspected that periods of rapid global warming and
cooling that happened so quickly most organisms were
not able to adjust.

48. WHAT CATASTROPHIC EVENT
CAUSED THE MASS
EXTINCTION??? 3 THINGS
• 1. volcanic activity
• 2. Climate Changes
• 3. lowering of sea levels as
Pangaea was forming
(convergent boundaries)

49. Mesozoic Era
(Age of the Dinosaurs or
Reptiles)
Three Periods
Triassic
Jurassic
Cretaceous

51. TIMEFRAME
• Occurred between 248 to 65 million years
ago

52. IMPORTANT FACTS
• Time marked by rapid movements of
plates
• A major geologic event of the Mesozoic
was the break-up of the super continent of
Pangaea into several large continents.
• At the beginning of this era Pangaea
formed and during the Triassic Period

53. Mesozoic Era
Triassic Period (225-180 MYA)
Pangaea (supercontinent) existed

54. PANGAEA

55. Mesozoic Era
Jurassic Period (180-135 MYA)
Pangaea starts to separate

56. Mesozoic Era
Cretaceous Period (135-65 MYA)
Continents in modern positions

57. ANIMALS/ORGANISMS (BIOLOGICAL)
WHAT FIRST APPEARED?
1. DINOSAURS
2. SMALL MAMMALS
3. BIRDS
WHAT ANIMAILS BECAME DOMINANT?
1. DINOSAURS
2. REPTILES

58. Mesozoic Era
Triassic Period (225-180 MYA)
First Dinosaurs
(small in size)
Pisanosaurus
Length:3 feet
Height:1 foot
Weight:15 pounds
Eoraptor:
Length:3 feet
Height: 1 foot
Weight:20
pounds

59. Mesozoic Era
Jurassic Period (180-135 MYA)
1st mammals (small rodents).

60. Mesozoic Era
Jurassic Period (180-135 MYA)
1st birds (Archaeopteryx).
• Jaws and bone structure like
dinosaurs
• Bones are hollow, like birds
• Had feathers

61. LAND (GEOLOGICAL) FEATURES
• WHAT LAND FEATURES FIRST
APPEARED?
1. Flowering plants
• WHAT LAND FEATURES BECAME
DOMINANT?
• 1. SEED PANTS

62. Mesozoic Era
Cretaceous Period (135-65 MYA)
Flower plants CALLED
(angiosperms) 1ST
APPEARED

63. • WHAT CATASTROPHIC EVENT
CAUSED THE MASS EXTINCTION?
• Scientists hypothesize that
possibly a large _asteroids__ or
_comets__ impacted with Earth.
• The mass extinction that ended the era
caused the dinosaurs to become extinct.

64. MASS EXTINCTION
• Asteroids, METEORITE, or Comets
collided into the Earth AND CAUSED
Mass Extinction

68. How could a meteorite impact
cause a mass extinction?
• The impact caused shock waves,
tidal waves, and sent a tremendous
amount of dust into the atmosphere
 As the dust re-entered the Earth’s atmosphere, it
would have instantly heated the atmosphere
causing tremendous forest fires
 Dust from impact blocked out the sun and
caused major climate change and plants to die
 Plants, animals, etc. went extinct due to the
climate changes and competition between
organisms

69. Cenozoic Era
(Age of the Mammals)
Two Periods
Tertiary
Quaternary

70. TIMEFRAME
• TIMEFRAME: 65 million years ago
to Present Day

71. IMPORTANT FACTS:
• Present day Earth is in this era.
• The diversity of life forms increased
because of the variety of different animal
and plant species that formed.
• New mammals appeared while others
became extinct.
• A major geologic event of the Cenozoic is
the further splitting and moving of
continents to their current positions.

74. ANIMALS/ORGANISMS (BIOLOGICAL)
• WHAT MAMMALS/ANIMALS FIRST
APPEARED?
1. Humans
WHAT MAMMALS/ANIMALS BECAME
DOMINANT?
1. MAMMALS

75. • HUMANS 1ST APPEARED (HOMO
SAPIENS)

76. Cenozoic Mammals

77. MAMMALS

78. GEOLOGICAL (Land)
FEATURES
• WHAT LAND FEATURES BECAME
DOMINANT?
1. FLOWERING PLANTS

79. Flowering Plants were common
during the Cenozoic Era

81. WHAT CAUSED THE MASS
EXTINCTION?
• There have been SOME extinctions
CAUSED BY Climatic Changes &
Glacier Events (Ice Ages) during the
Cenozoic as there were during the
Mesozoic and Paleozoic, but not as
many animals and plants have
disappeared.
• The “Great Ice Age”, ice sheets covered
30% of all land
•

82. The Great
Ice Age

83. 5 Question Quiz
1. Which era is the age of dinosaurs?
2. Which era is the age of trilobites?
3. Which era is the age of mammals?
4. What is the connection between periods,
eons, eras, and epochs?
5. Give 2 facts about the Precambrian
Time.