Transcript Volcanoes - TeacherWeb

Volcanoes
6th 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 coneshaped?
• 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