Continental Drift
Who came up with the theory of Continental Drift
Alfred Wegener
Where does seafloor spreading occur?
What is the name of the tectonic plate we live on?
North American plate
What are the 3 types of rocks?
Igenous
Sedimentary
Metamorphic
What was Alfred Wegener's occupation?
meteorologist
What is the name of the supercontinent before continents drifted?
Pangea
1. Who discovered seafloor spreading was occuring?
2. What did he use to discover this?
1. Harry Hess
2. Sonar
Where are the tectonic plates located?
In the crust/lithosphere
What type(s) of rocks are found in Central CT and how did they form?
Igneous - lava erupted through cracks when plates were diverging
Sedimentary - water runoff down mountains carried sediment into the valley and hardened into rock.
What are the layers of earth?
Inner core
Outer core
Mantle (asthenophere)
Crust (lithosphere)
What was the evidence that continental drift has occurred?
1. Same fossils found on different continents
2. Coastlines matching
3. Glacial evidence found in warm climates
What causes seafloor spreading?
Movement of tectonic plates driven by convection currents in the mantle
(if you just wrote movement of plates, you get half credit)
At what plate boundary does subduction occur at, and why does one plate subduct under another?
Convergent boundary; the plate that is denser will subduct under the other less dense plate.
What formed first: the Central CT valley or the Eastern/Western highlands of CT?
Eastern/western highlands of CT
The North American plate and Eurasian plate are drifiting away from each other at a rate of ____cm per year.
2.5 cm per year
Why did many scientists not believe that the continents drifted apart?
Because at the time, there was no explanation for HOW/WHY the continents drifted
At what type of plate boundary does sea floor spreading occur?
Divergent boundary
Describe the 3 types of plate boundaries? (you can draw them instead)
divergent: 2 plates move apart
convergent: 2 plates come together
transform: 2 plates slide past each other
What type(s) of rocks are found in Eastern/Western CT and how did they form?
Metamorphic - made from the heat and pressure of mountain formation from converging plates
What is the name of the deep crack in the African continent where a divergent boundary is slowly spreading apart?
Great Rift Valley
About how many years did it take for Pangea to form and then break apart into what the continents look like today?
~ 550 million years
What is the evidence that sea floor spreading occurs?
1. Ages of rocks --> older rock found along the coasts, younger rock found near middle of ocean
2. Magnetic striping --> the rocks are in a pattern showing a record of reversals of Earth’s magnetic field
3. Magma --> pillow-shaped rocks found on the ocean floor could only have formed when mamga hardened quickly after erupting underwater
What is a nickname for the plate boundary around the Pacific ocean, known for its many volcanoes?
Ring of Fire
Put these events in order from first to last:
1. This process formed metamorphic rock that is older and higher in elevation.
2. Diverging plates formed the central valley.
3. Converging plates formed the eastern/western highlands.
4. This process formed igneous and sedimentary rock that is younger and lower in elevation.
3. Converging plates formed the eastern/western highlands.
1. This process formed metamorphic rock that is older and higher in elevation.
2. Diverging plates formed the central valley.
4. This process formed igneous and sedimentary rock that is younger and lower in elevation.
What was name of the dinosaur whose fossils were found on both South America and Africa?
Cynognathus or Mesosaurus