9654467111 Call Girls In Raj Nagar Delhi Short 1500 Night 6000
Seafloor Spreading theory.pptx
1. What is Continental Drift Theory?
State that the continents were once part of a large
landmass called PANGAEA which drifted away
from each other. The continents move away from
each other towards their current position.
2. What are the evidences of the
continental drift theory?
1.The apparent fit of the continents
2.Fossil Correlation
3.Rock and mountain correlation
4.Paleoclimate data
3. In the early 1960’s scientist Harry Hess,
together with Robert Dietz suggested an
explanation to the continental drift. This is
the Seafloor spreading theory.
4.
5.
6. According to this theory, hot, less dense material
from below the earth’s crust rises towards the
surface at the mid-ocean ridge. This material flows
sideways carrying the seafloor away from the ridge,
and creates a crack in the crust. The magma flows
out of the crack, cools down and becomes the new
seafloor.
7.
8. What is the most active sites of
seafloor spreading?
10. What are the different findings that
support Seafloor Spreading Theory?
1. Rocks are younger at the mid-ocean ridge.
2. Rocks far from the mid-ocean ridge are older.
3. Sediments are thinner at the ridge.
4. Rocks at the ocean floor are younger than those at
the continents.
11. What are the evidences that proves
the Seafloor Spreading Theory?
1. Magnetic Reversal
2. Magnetic Polarity
12. What is Magnetic Reversal? How
does magnetic reversal happen and
how does it prove seafloor
spreading?
17. The seafloor spreading theory contradicts a
part of the continental drift theory. According
to this theory, continents moved through
unmoving oceans and that larger, sturdier
continents broke through the oceanic crust.
Whereas, the seafloor spreading shows that the
ocean is the actual site of tectonic activity.
