How Does Magma Affect Land Features?

D35

• Underground magma can cool and harden in many shapes and forms before it reaches the surface

• Dike: hardens in vertical cracks

• Sill: hardens between horizontal layers of rock (flat)

• Laccolith: Magma pushes into a sill to form a pocket, pushes rock layers up into dome mountains.

• Dome mountains: broad, circular mountains formed from uplifted rock layers (Black Hills of South Dakota)

• Batholiths: largest and deepest underground formation- if above sea level it looks like large steep hills

Dome Mountain

What feature is this?

• Dome mountain

• Batholith

• Dike formation

• A sill

• Laccolith