Intrusive Features/Landforms - SS3 Geography Lesson Note

Batholiths: These are large, dome-shaped rock masses formed from the solidification of magma deep within the Earth. They can cover vast areas and are often composed of coarse-grained rocks like granite.

 

Dikes: Dikes are vertical or near-vertical walls of igneous rock that cut across existing rock layers. They form when magma intrudes into existing rock layers and solidifies.

 

Sills: Sills are horizontal layers of igneous rock that are injected between existing rock layers. They form when magma is forced between sedimentary rock layers and cools.

 

Laccoliths: Laccoliths are similar to batholiths but smaller and typically lens-shaped. They result from the intrusion of magma between rock layers, causing the overlying rocks to arch upward.

 

Stocks: Stocks are smaller intrusive rock bodies, often less than 100 square kilometers in size. They can be exposed at the surface or buried beneath other rocks.