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New TheoryWegener could not explain how they moved.New theory of plate tectonics
Continental Drift
Plate TectonicsA plate is one of numerous rigid sections of the
lithosphere that move as a unit over the material of the asthenosphere.
Types of Plate Boundaries
9.2 Plate Tectonics
Divergent boundaries (also called spreading centers) are the place where two plates move apart.
Convergent boundaries form where two plates move together.
Transform fault boundaries are margins where two plates grind past each other without the production or destruction of the lithosphere.
Spreading Center
Oceanic-Continental Convergent Boundary
Oceanic-Continental Convergent Boundary
Oceanic-Continental Convergent Boundary
Collision of India and Asia
Transform Fault
LEQ #4
Why are trees, volcanoes and ice
key to our understanding of earth’s history?
Get ready for your mind to be…BLOWN!
The Earth actually gets COLDER after big volcanic eruptions!
How do volcanic eruptions effect the
Earth’s temp? 1. Dust, ash,
glass, and rock are released into the air during a volcanic eruption.
2. These things block the sun from reaching earth!
Clouds of ash can cover entire
continents!
In 2010, the Icelandic volcano Eyjafjallajokull erupted, spewing thousands of tons of ash into the air. 95,000 European flights were cancelled as a result of the eruption!
What information do Ice Cores & Tree Rings tell us?
-Tell us how the CLIMATE has changed over
time
Ice core- a sample of ice and snow that have built up over thousands of years
-tell the amount of gasses in Earth’s atmosphere over time.
Why do we care about ice?
What do ice cores tell us about the climate?
Black or brown coloring- VOLCANIC ERUPTION (color caused by the ash)
Yellowish color-Pollution in the air
Bubbles- Carbon Dioxide (CO2) is in the air (lots of bubbles means that is was HOT!)
Why do we care about trees?
Tree Rings: tell the amount of rain over time
-Big Rings- A LOT OF RAIN
-Skinny Rings- DROUGHTS
Why do we care about trees?
Tree Rings
-One ring= one year
*Youngest- on the outside
*Oldest- on the inside
Precambrian Era5 Major events:
Formation of Sun and lightCreation of EarthCreation of Atmosphere through volcanic
out-gassingCreation of oceansCreation of life
Simple life such as bacteria and simple algae
There was a rise of simple organism such as jellyfish and sea worms by end of era.
Few fossils because life forms were soft-bodied and had no hard skeleton.
Precambrian EraPrecambrian lasted the longest; 88% of
Earth’s history.
Earth took about 3.5 billion years to form; making it around 4.6 billion years old.
Paleozoic EraBegan with the early invertebrates (no
backbone), such as trilobites and brachiopods; continued to develop early vertebrate fish, then arachnids and insects; later came the first amphibians, and near the era’s end the reptiles became dominant.
Early land plants include simple mosses, ferns, and then cone-bearing plants.
By the end of the era, seed plants were common.
The mass extinction that ended the era caused most marine invertebrates as well as amphibians to disappear.
Mesozoic EraReptiles were the dominant animals
of this era, including the various dinosaurs.
Small mammals and birds also appeared.
Toward the end of the era, flowering plants appeared and the kinds of mammals increased.
A mass extinction that ended the dinosaurs.
Cenozoic EraNew mammals appeared while other
became extinct.
The diversity of life forms increased.
Flowering plants became most common.
Humans are also part of the most recent period.
FactsScientists believe that when a sudden
disappearance of many animals took place there was a mass extinction. This would show up as many fossils in
one layer.
