What is a laccolith?

A laccolith is a geological formation that occurs when magma intrudes into sedimentary layers and accumulates between these layers, causing them to bulge upwards. This process results in a dome-like structure that can vary in size. The magma does not erupt from the Earth’s surface in the case of a laccolith; instead, it solidifies underground, forming igneous rock.

Understanding this formation is crucial in geology, as it illustrates the interaction between different types of rock layers and magma within the Earth’s crust. The structure of a laccolith can help geologists understand the history of volcanic activity in a certain area, the types of rocks present, and the conditions under which they formed. This definition highlights the specific characteristics that make a laccolith unique from other geological features, such as volcanoes or magma chambers.