10 3 Plate Tectonics and Igneous Activity Do

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.

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

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

Intraplate Igneous Activity

Group Challenge Question • Describe the Ring of Fire