Transcript 10.3

10.3 – Plate Tectonics and Igneous
Activity
Do Now
•How are the locations of volcanoes
related to plate boundaries?
Do Now
•How are the locations of volcanoes
related to plate boundaries?
• Plate motion provide the mechanisms
by which mantle rocks melt to
generate magma.
Key Words
Magma Plume
Vocab Words
Intraplate Volcanism
Plate Tectonics and
Igneous Activity
•More than 800 active volcanoes have been
identified worldwide.
• Most of them located in the Ring of Fire.
• The circum-Pacific belt
• A second group of them are found in deep-ocean basins.
• Hawaii and Iceland
• A third group are irregularly distributed in the interiors
of continents.
• Erta Ale for example.
Ring of Fire
Converging Plate
Boundaries
•The basic connection between plate tectonics and
volcanism is that plate motions provide the
mechanisms by which mantle rocks melt to generate
magma.
• Ocean-Ocean
• Rising magma can form volcanic island arcs in an ocean
(Aleutian Islands).
• Ocean-Continent
• Rising magma can form continental volcanic arcs (Andes
Mountains).
Convergent Plate
Boundaries
Convergent Plate
Boundaries
Convergent Plate
Boundaries
Divergent Plate
Boundaries
•The greatest volume of volcanic rock is
produced along the oceanic ridge system.
• Lithosphere falls apart
• Less pressure on underlying rocks
• Partial melting occurs
• Large quantities of fluid basaltic magma are
produced
Divergent Plate Boundaries
Intraplate Igneous
Activity
•Intraplate volcanism is igneous activity that occurs
within a tectonic plate away from plate boundaries.
• Most intraplate volcanism occurs where a mass of
hotter than normal mantle material called a mantle
plume rises toward the surface.
• The activity forms localized volcanic regions called hot
spots.
• Examples include the Hawaiian Islands and the
Columbia Plateau.
Intraplate Igneous Activity
Group Challenge
Question
•Describe the Ring of Fire