Lecture Notes: CH 10

Lecture Notes: CH 10

The Nature of Volcanic Eruptions

·  Dissolved gases, Temperature, and Composition in the magma

Volcanic Material

u  ______clastic Materials

u  ______produced in volcanic eruptions.

u  ______ejected during eruptions ______in size

u  (fine dust and ______(less than ___ millimeters) to pieces that weigh tons.

Types of Volcanoes

Shield Volcanoes

u  large, ______volcanoes built from ______lavas.

Cinder Cones

u  ______volcanoes built primarily of ______material ejected from a single vent.

Composite Cones (______)

u  composed of both ______

u  Known as ______-volcanoes

u  Most are adjacent to the ______(Pacific Ocean)
(e.g., Mt. Rainier and ______).

u  Large size Interbedded lavas and pyroclastics

u  ______(due to size) type of activity

10.2 Intrusive Igneous Activity

Plutons

u  intrusive igneous structures that result from the ______(classified by ______, and relationship to surrounding rock layers)

Lava Plateaus

u  ______extruded from crustal fractures ______

Sills and ______

u  Are ______that form when magma is ______to the surface.

u  Sills ______and may exhibit columnar joints.

Laccoliths are ______-shaped masses that arch overlying strata upward.

Dikes

u  ______-shaped intrusive igneous features that ______layers.

Batholiths - ______masses of ______- formed when magma ______, became crystallized, and subsequently ______.

u  must have a surface exposure ______ to be a batholith.

Origin of Magma

u  originates when solid ______the ______(crust and upper mantle), partially ______by raising temperature above melting point

Role of Heat - The geothermal ______—Earth’s natural ______(______deg C every ______!) with depth but is not sufficient to melt rock in the ______

u  Role of Water (ocean) - Causes rock ______temperature

10.3 Plate Tectonics and Igneous Activity

Divergent Plate Boundaries

u  ______volcanic rock is ______along ______system.

Volcanoes Under the Ocean

•  Seamount: an ______

•  Look much like ______/composite volcanoes

Intraplate Igneous Activity

u  Intraplate volcanism activity within (______) a tectonic plate

Most intraplate volcanism: a mass of ______material (mantle plume) rises.

Where Do Volcanoes Occur? Along the ______

•  ______: volcano that occurs in the ______

–  Mantle plume rise from ______the mantle

–  An ______if lava & ash build up

–  As the plate keeps moving, a ______develops (______Islands)

In which of the following areas is a volcano least likely to form? ______

Which type of volcano is the smallest and most abundant and tends to be active for short periods of time? ______

Draw Pictures of each of the 3 types of volcanoes then compare with the back