Igneous rock formed when magma is squeezed into a vertical (up and down) crack that cuts across rock layers and solidifies underground.
What is a dike
100
Plate boundary where plates are moving apart.
What is divergent
100
Quiet eruptions, magma relatively low in silica.
What is basaltic
100
This volcano is composed mainly of quiet basaltic lava flows forming a broad gently sloping.
What is a shield volcano
100
A mountain formed at an opening in Earth’s surface that erupts gases, ashes, and lava; can form at Earth’s plate boundaries where plates move apart, together or at hot spots.
What is a volcano
200
Igneous rock formed when magma is squeezed into a horizontal crack (sideways) across rock layers and solidifies underground.
What is a sill
200
Plate boundary where plates are moving together.
What is convergent
200
Molten rock that flows from volcanoes onto Earth's surface.
What is lava
200
Many shield volcanoes make up this region.
What are the Hawaiian Islands
200
Opening where magma is forced up and flows out onto Earth’s surface as lava, forming a volcano.
What is a vent
300
Largest intrusive igneous rock body that forms when magma is forced upward toward the crust, cools and solidifies underground.
What is a batholith
300
Plate movement where plates converge and a less dense plate moves below a more dense plate.
What is subduction
300
Hot melted rock material beneath Earth's surface.
What is magma
300
Volcano built by alternating layers of quiet lava and explosive tephra.
What is a composite volcano
300
A steep walled depression around a volcano’s vent.
What is a crater
400
Solid igneous core of a volcano left behind after the softer cone has been eroded.
What is a volcanic neck
400
Hot rock at an area that is forced up toward the crust where it is partially melted and is not near a plate boundary, but in the middle of a plate.
What is a Hot Spot
400
Magma that is high in silica content and more explosive.
What is andesitic
400
A loosely packed, steep sided volcano formed from bits of tephra
What is a cinder cone volcano
400
Large circular-shaped opening formed when the top of a volcano collapses.
What is a caldera
500
Lava or magma that hardens as an igneous rock.
What is cooling slowly
500
A belt of active volcanoes that circles the Pacific Plate region.
What is the Ring of Fire
500
Another important factor besides amount of silica in whether an eruption is explosive.
What are trapped gases and water vapor
500
An example of a composite/strato volcano found in Washington that had a powerful eruption in 1980.
What is Mt St. Helens
500
Bits of rock or solidified lava dropped from the air during an explosive volcanic eruption. Can range in size from ash to the size of cinder blocks.