Sea floor spreading with article

Which of the following pieces of evidence does not explain how mid-ocean ridges are formed?

• The rocks closer to the ridge are younger than those farther away.

• Mid-ocean ridges are found on the bottom of most oceans.

• The magnetic orientation of rocks is symmetrical on either side of mid-ocean ridges.

• Pictures of ridges show evidence of lava flows.

Which statement correctly defines a divergent boundary?

• A small part of Earth's mantle

• A location of high volcanic activity

• A location where tectonic plates move apart

• A section of crust that moves as a unit

Which of the following is least necessary for plate tectonics?

• A solid core inside the planet

• A semi-solid mantle

• Convection currents in the mantle

• A crust divided into plates

Which of the following statements regarding a convergent plate boundary between continental crust and oceanic crust is not true?

• Earthquakes are common at the boundary.

• Mountains are formed.

• Hot spots that may create volcanoes are formed.

• Oceanic crust changes into continents.

Subduction of ocean crust happens-

• at a mid-oceanic ridge.

• far from tectonic plate boundaries.

• inside volcanoes of the Ring of Fire.

• In deep ocean trenches.

What evidence suggests that the Australian and Indian plates are separating?

• The formation of a new oceanic ridge

• Recent large magnitude earthquakes

• The way earthquake waves travel through the area

• The presence of a string of volcanoes