Volcanoes and Tectonics

Location of volcanoes
"Ring of fire"
Tip of Chile to New Guinea
Other island arcs
Mid-ocean
Hawaii, Tahiti, Azores
Within continents
Mt. Kilamanjaro

Continental margins
Andean volcanoes
Central America
North America

Island arcs
Aleutians
Kamchatka-Japan
Isu-Mariana
Indonesia
Tonga-Kermadec
South Sandwich
Caribbean

Mid-ocean volcanoes
Hawaiian chain
Polynesian islands
Islands of the Atlantic
Iceland, Azores, Canaries

Continental rifts
African rift valley
Rhine valley
Western USA

Isolated Continental Volcanoes
North Africa
Jebel Marra, Sudan
Tibesti, Chad
Ahoggar, Algeria
Antarctica
Mt. Erebus

Structure of the earth
Core
Mantle
Crust
Lithosphere
Aesthenosphere

Mantle
Composition
Physical Characteristics
Moho
Creep deformation
Significance for volcanism
Source of primary magmas

Crust
Types (Continental vs oceanic)
Physical characteristics
Rigid
10 - 60 km thick
Evolved composition
Significance for volcanism
Migration paths to the surface
Contamination of primary magmas
Magma chambers
Plate margins

Lithosphere
Contains crust and mantle
Defined by brittle behavior
Upper temp. of about 1350o C
100 to 150 km thick

Aesthenosphere
Essentially mantle material
Moves by convection
Source for most primary magmas

Plate tectonics
Few (7) large rigid plates
Several smaller ones
Plate margins
Two-plates
Triple junctions
Plate movement
Various rates and styles
Explains most volcanism

Relationships between plates
Convergence
Destructive margins
Divergence
Constructive margins
Transform
Lateral displacement

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