Thrust Faults What kind of fault is it? Precambrian Paleozoic.
Scientists have divided geologic history into 4 main parts: Precambrian Time Paleozoic Era Mesozoic...
-
Upload
felicia-gilbert -
Category
Documents
-
view
224 -
download
3
Transcript of Scientists have divided geologic history into 4 main parts: Precambrian Time Paleozoic Era Mesozoic...
ERAS OF THE GEOLOGIC TIME SCALE
SCIENTISTS HAVE DIVIDED THE EARTH’S HISTORY INTO 4 MAJOR PARTS:
THE GEOLOGIC TIME SCALE
Scientists have divided geologic history into 4 main parts:
Precambrian TimePaleozoic EraMesozoic EraCenozoic Era
Precambrian Time
4.6 billion – 543 million years ago Life began during this time Atmosphere made of water vapor, CO2 & N2
Volcanic eruptions, meteorites, violent storms & intense solar radiation
Origin of Life?
• Extraterrestrial• Life came from outside the planet(i.e. meteor)
• Creation• Divine forces created life
• Non-Living Matter• Spontaneous assembly of molecules
4 billion years ago - Earth began to cool
Water condensed and fell as rain
Atmosphere of early Earth Hydrogen (H2) Volcanic gas
(i.e. methane (CH4), ammonia (NH3), CO, SO2, N2, CO2)
No free oxygen or ozone
Energy stimulated chemical reactions
=ProteinsNucleic AcidsLipidsCarbohydrates
UV
+
How Did Life Begin?
In the oceans Energy from radiation
and storms caused simple chemicals in the oceans & atmosphere to react
More complex molecules were made Molecules joined to form cells Prokaryotes: single-celled organisms
(without a nucleus) that did not need O2 to survive
Photosynthesis & Oxygen Cyanobacteria (type of prokaryotic
organism) appears over 3 bya Uses sunlight to produce food
Photosynthesis & Oxygen Oxygen gas is released into oceans & air Oxygen molecules react to form Ozone,
which absorbs harmful radiation form the sun
Now possible for life to exist on Earth’s surface
Photosynthesis & Oxygen
VOCs Volatile organic compounds
NOx Nitrogen-oxygen compounds
Multicellular Organisms
Eukaryotes appear in the fossil record Organism that contain a nucleus Will evolve into organisms composed of many
cells
Paleozoic Era (543 – 248 mya)
“Old life” or “Ancient life” Large fossil record
Sponges, coral, squid, clams, trilobites, fish, sharks
Reptiles, amphibians, fish, worms, & ferns first appear
Paleozoic Era – Life on Land
Plants, fungi, & air-breathing animals slowly colonized land Crawling insects first animals to live on land Reptiles & winged insects appear near the end
of era LARGEST Mass extinction marks end of
era 90% of species extinct Oceans completely changed
Mesozoic Era (248 – 65 mya)
“Middle Life” or “Age of Reptiles” Dinosaurs dominate Earth for 150 million
yrs First birds appear Conifers appear Flowering plants appear late in era
End of Mesozoic Era
Mass Extinction Dinosaurs Many other plant & animal species Meteorite hit Earth
Dust, smoke, fires Temperatures dropped
for many years
Cenozoic Era (65 mya – today)
“Recent Life” or “Age of Mammals” Many mammals, birds, insects &
flowering plants Saber-toothed cats,
camels, small horses
Cenozoic Era Today
Era we are currently living in Climate changed many times during era
Periods of ice ages Animals migrate, adapt, or become extinct