Science Vocabulary~Chapter 12

Front 1

batholith

Back 1

largest instructive igneous rock body that forms when magma being forced upward toward the earth's crust cools slowly and solidfies underground.

Front 2

caldera

Back 2

large, circular-shaped opening formed when the top of the volcano colapsed.

Front 3

cinder cone volcano

Back 3

steep-sided, loosely packed volcano formed when tephra falls to the ground.

Front 4

composite volcano

Back 4

volcano built alternating explosive and quite eruptions that produce layers of tephra and lava; found mostly where earth's plates come together and one plate sinks below the other.

Front 5

crater

Back 5

step walled depression around a volcano vent.

Front 6

dike

Back 6

igneous rock feature formed when magma is squeezed into a verticle crack that cuts across rock layers and hardens underground.

Front 7

hot spot

Back 7

the result of an unusual hot area at the boundry between Earth's mantle and core that forms volcanoes when melted rock is forced upward and breaks through the crust.

Front 8

shield volcano

Back 8

broad gently sloping volcano formed by quiet eruptions of basaltic lava.

Front 9

sill

Back 9

igneous rock feature formed when magma is squeezed into a horizontal crack between layers of rock and hardens underground.

Front 10

tephra

Back 10

bits of rock or solidfied lava dropped fromthe air during an explosive volcanic eruption; rangers in size from volcanoc ash to volcano bombs and blocks.

Front 11

vent

Back 11

opening where magma is forced up and flows out onto Earth's surface as lava, forming a volcano.

Front 12

volcanic neck

Back 12

solid igneous core of a volcano belt behind after the softer core has been eroded.

Front 13

volcano

Back 13

opening in the earth's surface that erupts gases, ash, and lava; can form at earth's plate boundries, where plates move apart or together and at hot spots.