Volcanoes 6 th grade quiz practice Ms. Cooper’s class
What is the difference between Magma and Lava?
Magma is melted rock inside the earth. Once it comes out of the earth, it’s called lava
What do we call a volcano that is no longer able to erupt?
extinct
What do we call a volcano that has recently erupted?
Active
What do we call a volcano the are not active now, but may become active in the future?
dormant
What is the “Ring of Fire” and where is it?
A ring of volcanoes and earthquakes located where the oceanic crust of the Pacific Plate is subducting under other plates.
How are volcanic island chains formed?
As a lithospheric plate moves over a hot spot, a series of volcanoes form
What is the name for a flat and wide volcano that has low-silica magma with low or high levels of dissolved gas?
Shield Volcano
Where do Shield Volcanoes form?
Over Oceanic Plates
What kind of volcano has low-silica magma with high levels of dissolved gas that produce “fire fountain” eruptions?
Cinder cone
What kind of volcano that is formed by layers of silica-rich lava and ash is tall, explosive and cone- shaped?
Composite Volcano
Where do Composite Volcanoes form?
At Subduction zones (convergent plate boundries)
What kind of rocks are found at shield volcanoes?
Basalt
What kind of rocks are found at composite volcanoes?
Andesite Rhyolite Granite
Describe magma that is high in silica.
High Viscosity: Thick, sticky (like peanut butter)forms composite volcanoes
Describe magma that is low in silica.
Low Viscosity: Runny, thin (like ketchup). Forms shield or cinder cone volcanoes.
What is the name for a bowl shaped crater that forms on top of cinder cone volcanoes?
Caldera
How does cooling rate relate to crystal size in the formation of igneous rocks?
Slow cooling magma has time to form large crystals. Magma that cools quickly has smaller crystals. fast cooling obsidian slow cooling granite