In the illustration, at which site would you expect to find basaltic magma eruptions without volcanoes? (Please help!)

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1 Answer
Feb 8, 2018

D. At a rift valley the crust splits allowing basaltic magma to flow out without the force of a volcanos.

Explanation:

A. is a an illustration of a mid Atlantic ridge. Underseas volcanos form along the mid Atlantic and other Mid Ocean ridges. Some like in Iceland reach the surface.

B. Is an illustration of a hot spot volcano. These types of volcanos have formed the Hawaii islands. The island of Hawaii has an active volcano due to the action of a hot spot.

C. Is an illustration of a subduction zone. The heat and pressure that results from the ocean plate being pushed and pulled under a continental plate results in volcanos. Mt. St Helens is an example of volcano that results from a subduction zone.

D. is the correct answer, In a rift valley the magma can flow out through the break in the crust without forming a volcano. Western Oregon has vast lava beds of basaltic lava. There are no volcanos that were the source of these horizontal layers of lava.