4 pieces of evidence that led to plate tectonics

Question 1

ages of rock on the ocean floor

Answer 1

the farther away from the ridge, the older the rocks are. the ridge is where the crust is splitting apart. magma is rising at the ridge to form new crust

Question 2

magnetic reversals

Answer 2

the mineral magnetite is magnetic. grains of magnetite in molten magma line up like little magnets
the north ends of magnetite grains point to earths north pole and the south ends point to earths south pole

Question 3

locations of earthquakes n volcanoes

Answer 3

improvement in technology allow scientist to record earthquakes and volcanoes under the ocean floor as well as on land

Question 4

mapping the ocean floor

Answer 4

scientist mapping the floor were surprised to find deep trenches. these long narrow trenches usually run parallel to and near the edges of the oceans. they also found a huge mountain range that almost encircles the earth