What term describes mushroom-shaped bodies that dome overlying layers while spreading laterally?

The correct term for mushroom-shaped bodies that dome the overlying layers while spreading laterally is laccoliths. Laccoliths are formed when magma intrudes between layers of rock and pushes the overlying strata upwards, creating a bulge or dome-like structure. Unlike other types of igneous intrusions, laccoliths are typically characterized by a cap of overlying rock that is arched upwards, which results from the pressure exerted by the intruding magma.

Laccoliths are often found in areas of volcanic activity and can lead to significant geological features on the Earth's surface. Their lateral spread is a key characteristic that distinguishes them from other volcanic intrusions.

In comparison, batholiths are larger bodies of igneous rock that have crystallized from molten magma deep within the Earth's crust but do not typically show the same dome-like structure at the surface. Stocks are smaller than batholiths, while sills are tabular intrusions that are formed parallel to existing rock layers rather than causing a dome effect. Understanding these distinctions helps clarify why laccoliths are the correct answer in this context.