Section 10-4Igneous rock features
Batholith
Batholith Large intrusive rock
body Hundreds kilometers
wide Magma cools
underground Old magma chamber
laccolith
Laccoliths are somewhat large intrusions that result in uplift and folding of the preexisting rocks above the intrusion. They are also concordant types of intrusions.
Dike – Vertical intrusion that
cuts across rock layers
Shiprock volcanic neck and dike, symbols of
New Mexico geology,west of Farmington, NM.
sill
Sill Horizontal intrusion of
magma between vertical layers or cracks
Volcanic neck
Volcanic neck – Hardened magma
inside of the vent Volcanic cone is
eroded away leaving the neck exposed
caldera
Top/crater of volcano collapses in on itself leaving a larger crater.
Caldera lake – Sometimes the crater
fills in with water creating a lake