Intrusive Igneous Activity:

What is a pluton?

An igneous intrusion, typically coarse-grained rock, formed below the surface.

How are plutons classified?

By shape (tabular, massive) and orientation (concordant, discordant).

What is a dike?

A tabular, discordant pluton that cuts across existing rock layers.

What is a sill?

A tabular, concordant pluton that is parallel to the surrounding rock layers.

What is a laccolith?

A large, dome-shaped sill that pushes up the overlying strata.

What is a batholith?

The largest type of intrusive granitic body, often forming the core of mountain ranges.