OCEANIC CRUST

Question 1

oceanic crust composition in order

Answer 1

1-sediments
2a-pillow lava
2b-sheeted dykes
3a-gabbro
3b-layered gabbros
4-layered peridotite/upper mantle

Question 2

oceanic crust composition description

Answer 2

composed of various basic/ultra-basic igneous rocks which occur in a predictable association as an opthiolite complex

Question 3

mid-ocean ridge vents

Answer 3

like geysers, or hot springs, on the ocean floor.

along mid-ocean ridges where tectonic plates spread apart, magma rises and cools to form new crust and volcanic mountain chains.

seawater circulates deep in the ocean’s crust and becomes super-heated by hot magma

Question 4

magnetic reversal

Answer 4

process by which the north pole is transformed into a south pole and the south pole becomes a north

Question 5

magnetic reversal evidence

Answer 5

as rocks are formed where plates are moving away from one another, they record the current direction of the Earth’s magnetic field, which flip-flops irregularly over very long periods of time