1. Bellwork Ch 18-Volcanic Activity Compare/Contrast- Types of Volcanoes Directions- Open your binder to the bellwork section and complete the table. (Textbook p480)
Shield
Cinder-Cone
Composite
Drawing
Shape
Wide, kind of flat
Steep sides, small volcano
Large, wider
Type of Eruptions
quiet
More explosive than shield
violent
Low/High
Gas content
low
Higher than shield
High
Low/High Silica content
More silica & water than shield
High silica, water
Viscosity
Very high

2. Ch 18- Volcanic Activity
Take out your notes. As we go over chapter 18, add missing details to your notes (main idea)

3. Volcano
A naturally occurring opening in the surface of the Earth through which molten, gaseous, and solid material is ejected

4. MAGMA Mixture of molten rock Suspended by mineral grains Dissolved gas
Forms:
High temperatures
Pressure
Water
Source material

5. TYPES OF MAGMA Basaltic Andesitic Rhyolitic Basalt igneous rock
Ex: Hawaiian Islands
Andesitic
Andesite igneous rock
Ex: Mt. Saint Helens / Tambora
Rhyolitic
Granite igneous rock
Ex: Yellowstone Nat’l Park

6. What is viscosity? Property of fluid that resists flowing
The hotter the magma or lava, the lower the viscosity.

7. MAGMA COMPOSITION & CHARACTERISTICS

8. HOW MAGMA AFFECTS THE CRUST
BLOCKS TO BREAK OFF AND SINK
MELTS OTHER ROCKS
ROCKS TO FRACTURE

9. PLUTONS When magma cools, minerals form.
Over a very long period of time, these minerals will combine to form intrusive igneous rock bodies called plutons.
Largest plutons are called batholiths. Common in the interiors of major mountain chains. – primarily granite
Irregular shaped plutons are called stocks.
Mushroom-shaped pluton is called a laccoliths.
Sills – pluton intrudes parallel to layer rocks.
Dikes cuts across preexisting rocks.
Coast Range Batholith in British Columbia

10. PLUTONS

11. Parts of a Volcano
VENT- the vent is the opening from which lava flows. Dust, ash, and rock particles can also be thrown out of the vent!

12. Crater- the top of the volcano. It is a funnel shaped pit
Crater- the top of the volcano. It is a funnel shaped pit. It is formed when the material explodes out of the vent!

13. Volcanic cone-
is the pile of
lava, dust, ashes,
and rock around
the vent. It can
be found in different shapes!

14. 3 Types of Volcanoes Shield Cinder Cone Composite
They are classified by how they form.

15. Shield Volcano Is wide and somewhat flat.
It forms from a quiet eruption.
Lava flows out quietly and for great distances.

16. Cinder Cone Volcano Has tall, very steep sides.
Has explosive eruptions.
This eruption produces a lot of cinder and ash.

17. Composite Volcano Form from explosive eruptions.
Produce a lot of lava and ash.
Is small, with steep sides.

18. Tephra
Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground.

19. Pyroclastic flow
Swift-moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a violent eruption.

20. Hot Spot
Unusually hot area in Earth’s mantle that is stationary for long periods of time, where high-temperature plumes of mantle material rise toward the surface.

21. Where do volcanoes occur?
Active volcanoes generally occur close to the major tectonic plate boundaries. Along convergent and divergent plate boundaries.
They also form over hot spots – hot areas in the mantle
Volcanoes can remain inactive, or dormant, for hundreds or thousands of years before erupting again. During this time they can become covered by vegetation making them difficult to identify. Once a volcano has been dormant for more than 10,000 years, it is termed extinct.

22. Test- Plate Tectonics/Volcanoes Next Class. Frida
Test- Plate Tectonics/Volcanoes Next Class!! Frida * Be sure to study from the study guides, notes, bell work, class work and homework.

23. Classwork/Assignment Textbook/Review for exam
Problem-Solving Lab- Textbook page 486 Analysis Qs 1,2/ Think Critically Qs 3,4
Page 447 Compare/Contrast #6
Page 454 Concept Mapping # 6
Page 459 Making Tables # 6
Page 475 Concept Mapping # 7
You may work with a partner- All work is due in basket at the end of class!!!