Section 10-4 Where does most igneous activity take place? Define the following terms for igneous rock features: Batholith Dike Sill Laccolith Volcanic neck Caldera

Batholith – the largest intrusive igneous rock body forms when magma cools and solidifies underground and stops rising to the surface

Dike – forms when magma is squeezed into a vertical crack that cuts across rock layers and solidifies underground Sill – forms when magma is squeezed into a horizontal crack between rock layers and solidifies underground

Laccolith – a dome of rock that forms when a sill pushes the rock layers upward

Volcanic neck – the solid igneous core of a vent that remains after the outer layers of lava and tephra have been eroded away from an extinct volcano

Caldera – the large opening formed at the top of a volcano when a crater collapses into the vent following an eruption

Mountains p. 123-125 Describe the 4 main types of mountains.

Folded mountains – are created when rock layers are squeezed from opposite sides, causing them to buckle and fold

Upwarped mountains – are formed when Earth’s crust is pushed up and eroded, forming sharp peaks and ridges

Fault-block mountains – jagged mountains formed from huge, tilted blocks of rock that are separated from surrounding rock by faults

Volcanic mountains – created when magma within Earth escapes to the surface, building cones of lava and ash