Inside Earth Chapter 3.3Pages 103-107

Volcanic Landforms

Shield Volcano• Shield Volcano: a wide base mountain

with very gentle slopes– Lava pours out in thin layers and harden on top

of older layers.– Viscosity = Low

?

Viscosity• Viscosity is a substance’s resistance to flow• How much a substance tries NOT to flow• “Go with the flow” vs. “Going against the

flowing”

Viscosity

Cinder Cone• Cinder Cone: steep, cone-shaped hill or

mountain– May produce ash, cinders and bombs– Paricutin in Mexico (424m high)– Viscosity = High

Composite Volcano• Composite: gently steeping, cone-shaped

volcano which alternates eruptions of lava flows and violent eruptions (ash, cinder and bombs)

• Viscosity = High/Low• Examples: Mt. St Helens, Mt.

Fuji in Japan

Exit PassWhat are the 3 types of

volcanoes? Describe one of them.

Lava Plateau• High, level areas formed by lava

flows• Thin lava floods out, travels far

before cooling & solidifying• Flooding process repeats again

& again, building up high plateaus over millions of years– Columbia Plateau

(Washington, Oregon, & Idaho)

Caldera• Massive eruption empties the main vent and

magma chamber beneath the volcano• The hollow mountain then collapses inward

due to lack of support• A Caldera is the large hole left behind• Fills with pieces of the volcano, ash and water– Crater Lake in Oregon

Soils from Lava & Ash• Ash releases potassium, phosphorus, nitrogen,

and other materials that plants need• Soil develops and plants are able to grow

Volcanic Neck• Forms from when magma hardens in a

volcano’s pipe– The softer rock wears away, exposing the hard rock

(weathering and erosion)

Sill• Magma that squeezes in between layers of

rock and solidifies (Horizontal like a window sill)

• Which letter shows the sill?B in the diagram

Dike• Hans Brinker, The Silver Skates

Dike• Magma that forces itself across rock layers and

solidifies (Vertical cuts through rock layers)• Which letter shows the dike?

C in the diagram

Batholith• Large rock masses that form the core of many

mountain ranges• Formed when a large body of magma cools

inside the crust• Which is batholith?– D in the diagram.

Dome Mountain• Formed by smaller

bodies of magma, when rising magma is blocked by horizontal layers of rock.– Forces rock layers to bend

upward into a dome shape.

– Rock layers above eventually erodes and leave the core exposed.

Exit PassWhat are 2 types of volcanic landforms? Describe one of

them.

What to Work On

• Answer Section 3.3 Review questions on page 107 (#s 1-3)

• Read and Outline Chapter 3.4, Volcanoes in the Solar System