Sea Floor Spreading

http://www.bioygeo.info/Animaciones/SeafloorMagnet.swf

What is Sea Floor Spreading?

• Around the planet, there are ridges (under water mountain ranges) where new sea floor is being produced– Example: the Mid Atlantic Ridge

• At these locations, magma is rising and cooling into new oceanic crust

• As new crust is created, it forces the continental crust apart.

Evidence of SFS

• 1. Rock that makes up the ocean floor gets older as you move away from the mid-ocean ridge.

• 2.There is evidence of “new” rock (sea floor) along the mid-ocean ridge. – There is example of pillow lava on the ocean

floor.

• 3. There are magnetic stripes in the rock that make up the ocean floor.–As lava cools, the iron in the lava aligns with

the magnetic field.– This rock indicates the Earth’s magnetic field

has reversed itself.– The pattern or reversal is the same on both

sides of the mid-ocean ridge.

• http://www.bioygeo.info/Animaciones/SeafloorMagnet.swf

• http://gln.dcccd.edu/Geology_Demo/content/Lesson1/Geo01-14.swf

Free WriteExplain the theory of continental

drift stating at least three differentpieces of evidence.

Enrichment

Group A – (Back of the room) Peer grade responses. Once completed design your own supercontinent 250 million in the future.

Group B – (Front of the room) Compare paper with peer. Then , utilizing resources, find evidence to support your answer.

Group C – (With teacher)

• http://www.wwnorton.com/college/geo/egeo/flash/2_6.swf

• http://www.sepuplhs.org/middle/iaes/students/simulations/SEPUP_Plate_simulation.swf