Section 3 4 Volcanic Landforms Objectives F 3
Section 3 -4 Volcanic Landforms
Objectives F. 3. 4. 1. List the landforms that lava and ash create. F. 3. 4. 2. Explain how magma that hardens beneath Earth’s surface creates landforms. F. 3. 4. 3. Analyze other distinct features that occur in volcanic areas.
Landforms From Lava and Ash Volcanic eruptions create landforms made of lava, ash, and other materials. These landforms include shield volcanoes, cinder cone volcanoes, composite volcanoes, and lava plateaus. Objective F. 3. 4. 1.
Shield Volcanoes Quiet eruptions gradually layer over time to form gently sloping mountains. What can we infer about the magma in Shield Volcanoes? Low Viscosity Low Silica High Temperature
Shield Volcanoes
Does This Look Familiar? Hawaii
Cinder Cone Volcano Cinder cone volcanoes are made from ash, cinders and bombs during explosive eruptions. The are piled up and steep. What can we infer about magma that produces cinder cones?
Cinder Cone Volcanoes High Viscosity High Silica Content Low Temperature
Cinder Cone Volcanoes The Pinacate Peaks in Mexico are examples of Cinder Cone Volcanoes.
Composite Volcanoes Composite volcanoes alternate layers of quiet lava flows and explosive mass ejections. What can we infer about their magma. Medium Viscosity Medium silica content Medium temperature
Composite Volcanoes Mt. Fuji, in Japan, is a composite volcano.
Lava Plateaus Sometimes, instead of forming mountains, thin runny lava flows out of several cracks and flows for many miles before cooling and solidifying. These flows pile up to form large flat areas called plateaus.
Caldera A caldera is the huge hole left by the final collapse of a volcano. Which type of volcano would likely leave a caldera? Extinct
Crater Lake, Utah
Volcanic Soil Volcanic soil is very rich in nutrients and minerals. Plants and crops grow extremely well in volcanic soil. This is why people are so willing to live in the shadow of such a dangerous thing like a volcano.
Landforms From Magma Features formed by magma include volcanic necks, dikes, and sills, as well as batholiths and dome mountains. Objective F. 3. 4. 2.
Volcanic Neck A volcanic neck forms when the softer rock wears away from the denser rock exposing the original lava tube.
Volcanic Dike Volcanic dikes are formed when magma forces its way up across rock layers vertically.
Volcanic Sill A volcanic sill is magma that has forced its way out between rock layers horizontally.
Batholith A batholith is a large rock formation that occurs when a large pocket of magma cools inside the crust.
Dome Mountains A dome mountain forms when uplift pushes a hardened magma batholith up into the crust bending the layers of rock above it to bend into an arch.
Dome Mountain
Geothermal Activity Hot Springs and geysers are types of geothermal activity that are often present in places of current and past volcanic activity.
Yosemite National Park Hotspring Geyser
Geothermal Energy
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