volcanoes and plutons
DESCRIPTION
Volcanoes and Plutons. Process that forma Magma. Increasing Temperature Decreasing Pressure Addition of Water. Environments of Magma Formation. Spreading Center Mantle Plume Subduction Zone. Mantle Plume: Hot Spots . Hawaii Island animation Iris Hot Spot. Subduction Zone . - PowerPoint PPT PresentationTRANSCRIPT
Volcanoes and Plutons
Process that forma Magma
• Increasing Temperature• Decreasing Pressure• Addition of Water
Environments of Magma Formation
• Spreading Center• Mantle Plume• Subduction Zone
Hawaii Island animation
Iris Hot Spot
Mantle Plume: Hot Spots
Subduction Zone
Basalt and Granite• Asthenosphere is “PERIDOTITE”• PERIDOTITE =“OLIVINE+PYROXENE+ Ca-Feldspar”
Olivine 1,890°C, Pyroxene1,390°C, Calcium Feldspar 1,550°C
Peridotite 1,270°C the product of the first melt Rich In Silica Partial Melting: A small amount of original peridotite melts to form basaltic magma
Plutons• When a large granitic magma solidifies with in
Earth’s crust to form a large mass of Granite called a pluton
Types of Lava • Pahoehoe Low Viscosity, as it cools stiffens
forming smooth, glassy surfaced, wrinkled or ropy ridges
• Aa higher viscosity surface partially solidify as it flows
• Pillow lavas is a lava structure that typically when lava is emerged from an underwater volcanic vent.
• Pyroclastic rock rock fragments• Volcanic Ash
Volcanoes• When lava is too viscous to spread out as a
flood it builds a hill or mountain call Volcano
Shield Volcanoes• Basaltic Magma • Gentle sloping mountain• at angles 6° to 12°
Cinder Cones • Small volcano composed of Pyroclastic fragments• Large amount of gas accumulates in rising magma
Composite Volcanoes• Stratovolcano • form by longs periods of time by alternating lava flows and pyroclastic
material
Calderas
Volcanic Eruptions and Global Climate