1. Convergence

2. Put all 4 things in order from least to most dense.
Sea Water
Mantle
Sea water
Put all 4 things in order from least to most dense.
Continental crust
Oceanic crust
Mantle

3. When converging the less dense plate overrides
the denser plate subducts.
Basaltic oceanic crust (3.0 g/cm3) subducts below the overriding granitic continental crust (2.7 g/cm3).

5. CASCADE MOUNTAINS

6. CASCADE MOUNTAINS

7. Subducting crust melts and some magma bubbles up to form volcanoes.
Mt. Arenal, Costa Rica
Volcán Popocatépetl

8. Strong earthquakes occur when tectonic plates collide.
What’s here?
Strong earthquakes occur when tectonic plates collide.
Earthquakes get deeper as the subducting plate gets deeper.

10. Overriding crust folds with the force of the collision.

11. The result is uplift, forming true mountains.
Mt. Everest, Nepal/Tibet – 8,850m
Mt. Aconcagua, Argentina – 6962m
Adirondack Mountains (NYS)

12. Los Andes
Can you see the folded layers of crust?

13. Zones of Convergence Occur where tectonic plates meet.
Denser plate sinks below (subducts) less dense plate which floats above (overrides).
Crust melts and mountains uplift.
Create Volcanoes, Trenches, Folded Mountains, Earthquakes and Tsunamis.

14. Compared to the continental crust, the oceanic crust is
(1) less dense and thinner
(2) less dense and thicker
(3) more dense and thinner
(4) more dense and thicker

15. Between which two lithospheric plates could this boundary be located?
(1) South American Plate and African Plate
(2) Scotia Plate and Antarctic Plate
(3) Nazca Plate and South American Plate
(4) African Plate and Arabian Plate