1. Types of Volcanoes
Your Name Mr. Hertzog
Date 12-8-12
Earth Science
Content Objective: SSBAT describe the two different types of volcanoes: 1) one that has violent eruptions
producing steep slopes and 2) another that has lava that flows over a large area with gentle slopes.
Language Objective: SSBAT describe the various eras of the Geological Time by drawing, discussing, and labeling
the 3 types of volcanoes.
Anticipatory Set (15 minutes)
• What are the three types of volcanoes?
1) Have students draw volcanoes with a whiteboard marker on the board. Then circle the 3 types of volcanoes
that actually do exist.
Direct Instruction (15 minutes)
• Shield Volcanoes: broad at baseand have gentle sloping sides.Has quiet eruptions. Kilauea in Hawaii. Think of
flat sheets of rock that are layered like flat sheets of metal on a shield. Magma is very viscous (thick).Viscosity ,
or resistance to flow of magma affects how a volcano will erupt.Olympus Mons on Mars is the largest shield
volcano in the solar system.
• Cinder Cone Volcanoes: type of volcanomade up of ash, which is another word for cinders. Has steep slopes
and forms from explosive eruptions and are made of pyroclastic material (consists of fragments of rock that form
during a explosive eruption).Forms from highly viscous lava.
Types of pyroclastic material:
1) Volcanic ash: particles less than 2mm in diameter.
2) Volcanic dust: particles less than.25mm in diameter
3) Lapilli: particles less than 64mm in diameter that fall near the vent (Latin: “little stones”)
4) Volcanic bombs: large clots of lava that are round or spindle shaped
5) Volcanic blocks: form from solid rock that’s blasted from vent some the size of a small house
• Composite Volcanoes: made up of alternating layers of hardened lava flows and pyroclastic material
Mt. St. Helens
1) During quiet eruption lava flows over sides of cone
2) When explosive eruption occurs, large amounts of pyroclastic material are deposited around the vent.
3) Followed by quiet lava flows.
4) Commonly develop to form large volcanic mountains.
Two types of magma
o Mafic: magma or igneous rock rich in magnesium and iron and is dark in color. Oceanic volcanoes
commonly form from this type of magma.
o Felsic: magma or igneous rock rich in feldspar and silica and is light in colr
Guided Practice (20 minutes):
Have students draw, color, and label the three volcano types.
Closure (5 minutes):
• Review 3 types of volcanoes before bell rings.
• Have each student fill out an exit slip before leaving.
• Quiz on what was learned the following day in review (question of the day).
Independent Practice: Worksheet with pictures of three types of volcanoes.