Extra Plate Tectonics Questions Flashcards
When does a mid-ocean ridge form?
Whenever diverging plates continue to separate creating a new ocean basin. As the rising magma cools, it forms new ocean crust.
What happens when an oceanic plate converges with a less dense continental plate?
The denser oceanic plate sinks under the continental plate.
What happens when two oceanic plates converge?
The denser plate is forced beneath the other plate and volcanic islands form above the sinking plate.
The fact that the___rocks are located at the mid-ocean ridges is evidence for Seafloor spreading.
Youngest
The hypothesis that continents move slowly is called continental___
Drift
All continents once might have been connected in a large landmass called___
Pangaea
The cycle of heating, rising, cooling, and sinking is a___current.
Convection
Just below Earth’s crust is the___.
Mantle
The crust and part of the upper mantle are known as the___.
Lithosphere
Continental plates move on the plastic like layer of Earth’s surface called the___.
Asthenosphere
Hot magma forced upward at mid-ocean ridges produces seafloor___.
Spreading
Sections of Earth’s crust and upper mantle are called___.
Plates
The theory that Earth’s crust and upper mantle are I sections that move is called plate___.
Tectonics
Where are the youngest rocks found?
Close to the mid-ocean ridges
Which scientist invented echo-sounding devices for mapping the ocean floor?
Harry Hess
When plates collide, the____plate will ride over the____plate
- denser
- less-dense
Does Earth’s magnetic field always run from the North Pole to the South Pole?
No
Does the magnetic alignment in rocks on the ocean floor always run from the North Pole to the South Pole?
No
Evidence for continental drift
A.____fit of the continents
B. Similar___have been found on different continents
C. Remains of warm-weather plants in___areas and glacial deposits in___areas suggest that continents have moved.
D. Similar___structures are found on different continents.
- puzzle-like
- fossils
- glacial
- warm
- mountain
In the___, Harry Hess suggested ther theory of____to explain the ridges.
-plate tectonics
What are the three steps to Seafloor spreading?
- Hot, less dense material below Earth’s crust rises upward to the surface at the mid-ocean ridges.
- Then it flows sideways carrying the Seafloor away from the ridge.
- As the Seafloor spreads apart, magma moves up and flows from the cracks, cools, and forms new seafloor.
___rocks are located at mid-ocean ridges.
Younger
Reversals of Earth’s___field are recorded by rocks in strips parallele to ridges.
Magnetic
Denser plates sink under less___plates.
Dense
