Volcanoes
Notes:
Volcanoes Section 4
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 volcanos, and lava plateaus.
•Shield Volcanoes are created by lava flow that hardens and build up. ( quiet eruptions)
•Cinder cone Volcanoes are created by ash, cinder, and bombs. Steep Volcano ( Explosive eruptions)
•Composite Volcanoes are created by both explosive and quiet eruptions so the layers could be thick or thin.
•Lava Plateaus –due to the time it takes for lava to cool and solidify it can create a plateau instead of a mountain. They are made up of thin layers of lava. The lava will come from long cracks in the ground. See page 100-101
•Calderas are volcanic mountains that collapse to form a huge hole. See page 102
Landforms from Magma
These forms become visible by water, ice or wind striping away the layers of hard magma. These features include: volcanic necks, dikes, sills, as well as batholiths and dome mountains. See page 103
Dikes are seen slanting through bedrock along a highway cut.
Sills form between horizontal layers of rock.
Batholiths are large rock masses that form when a large body of magma cools inside the crust.
Dome Mountains will form when uplift pushes a batholiths or smaller body of hardened magma toward the surface.
Geothermal Activity
This is the heat from magma beneath the ground which will heat ground water like hot springs or geysers.
Hot springs are formed when groundwater is heated by a nearby body of magma or hot rock
Geysers are rising hot water or steam that is trapped underground in a narrow crack. Pressure will cause the water or steam to reach the surface.
Geothermal Energy can be used to heat homes and create electricity.