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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 .
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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
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 • PahoehoeLow 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