parts of a volcano magma chamber neck ◦ vent/crater cone/ash/lava flow tephra/so 2 /gases
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Volcanoes
Parts of a volcano Magma chamber Neck
◦ Vent/crater Cone/ash/lava
flow Tephra/SO2/gases
Cinder Cone
Steep sided cone Explosive
eruptions Lava type: tephra
◦ felsic◦ Traps gases, thick
Example: Paracutin Mexico
Plate bound – c/c
Shield volcano Rounded sides
◦ Dome Quiet eruptions Lava type: flows and
fountains◦ Mafic – no granite, little
gases, flows readily Example: Hawaii Plate bound: o/o
Strato volcano/ composite Cone not as steep as a
cinder cone Layers of tephra and
lava flow felsic and mafic Explosive and quiet
eruptions Example: Mt. St.
Helens, Mt Ranier Plate bound: o/c
Types of lava Pahoehoe:
◦ Quiet◦ Lava flow◦ Finger-like projections◦ Fast flowing like a river
pahoehoe
Aa - A type of lava having a rough, jagged surface.
It is relatively slow moving , thick
in the form of massive blocks
The blocks size between the size of a football and the size of a house.
Aa flow
Pillow lava – lava formed under water
tephra
Pele’s hair◦ Spun glass◦ Made by fountains◦ https://
www.youtube.com/watch?v=OEMyYNziXrc
◦ https://www.youtube.com/watch?v=Q8NXO6YxBmU
Pele’s tears Volcanic glass
Tephra
Pyroclastic flow
A pyroclastic flow a fast-moving
current of hot gas and rock (collectively known as tephra),
speeds moving away from a volcano of up to 450 mph.
Pyroclastic flow
Pompey
Hot spot
Hot spot Hawaii
Felsic Mafic
Temp Low High
SiO2 content High > 70% Low <50%
Volatile content High 10% water Low <2%
viscosity High (very thick) Low (very fluid)
Magma Properties
Type volcano Type lava Type boundary Type of Eruption
Dome/shield Hawaii
Mafic o/oHot spot quiet
Cinder cone Vesuvius/Etna
Felsic c/c explosive
Composite/Strato Mt. St. Helen’s
Mafic and Felsic o/c quiet/explosive
Relationship between volcanic type magma and plate boundary