Alfred Wegener did NOT use -------- ----- -------- to support his hypothesis of continental drift
Magnetic field data
What are 3 pieces of evidence did Wegener use to support his idea of continental drift ?
1. Ancient climate evidence 2. Data on ancient reptiles and ferns 3. Evidence from rock formations
Fossil evidence that supported wegener's idea of continental drift included...
Land dwelling animals
Fossils of aquatic reptiles found in freshwater Rocks Suggested to Wegener that these reptiles...
Did not cross the oceans
Based on observations of fossils of Glossopteris, Wegener concluded that...
Continental rocks containing these fossils had once been joined
Coal beds in Antarctica indicated to Wegener that these continent was ...
Once located closer to the equator
Based on the glacial deposits he observed Wegener argued that
Landmasses drifted away from the South Pole
Most scientists rejected wegeners hypothesis of continental dress because he
Couldn't explain how or why the continents moved
Maps made from ----- and ------------data led to the discovery of ocean ridges and deep-sea trenches
Sonar and magnetometer
Rock samples taken near ocean ridges are --------than rock samples taken your deep-sea trenches
The theory states that Ocean-crust is formed at Ocean ridges and is destroyed at deep-sea trenches
Sea floor spreading
A new sea floor, as it's carried away from ocean rides, ____ & _____ and becomes more _____ than the material beneath it
cools contracts dense
-------- --------- explains that Earths continents move because they ride atop ocean crust as it moves away from ocean ridges
Sea floor spreading
Fill in sequence w/ 1 2 3
_ magma fills gap that's created
_magma hardens to form new ocean crust
_magma is forced up toward crust
2 3 1
When the magnetic readings of the ocean floor are reversed, compared to today's field, the two fields partially -----
Isochron maps show that the ocean floor is ------- near ocean ridges and ----- deep see trenches
Minerals containing this act like small compass needles and record the orientation of Earth's magnetic field at the time of their formation
Each cycle of spreading and magma intrusion along an ocean ridge results in the formation of this
which theory states that earth's crust and rigid upper mantle move in different directions and at different rates over earth's surface?
when two oceanic plates converge and one is subducted into the mantle, the melted ----- erupts and forms an --- of -------
magma arc islands
when oceanic plate converges with a continental plate a ____ and a _____ ___ with ______ form
trench mountain range volcanoes
In the process of convection magma ____ because it is less ____ and the ___ matter goes ____ when it reached the surface it hits against making the surface _____ then the magma ____ so it's density _____ so it goes back down
Rises dense cool down separate cools increases
Convection currents in the mantle are related to plate motions by r___ ___ and s___ ___
Ridge push slab pull