What type of magma is stored within the Earth's crust?

Magma that is stored within the Earth's crust is referred to as intrusive magma. The key characteristic of intrusive magma is that it solidifies below the Earth's surface, which allows it to cool slowly, resulting in the formation of coarse-grained igneous rocks, such as granite. This slow cooling process gives intrusive rocks larger crystals compared to extrusive rocks, which form when magma erupts onto the surface and cools quickly.

Intrusive magma accumulates in magma chambers and can lead to the formation of various geological features over time. As tectonic plates move and shift, sometimes this intrusive magma can be exposed at the surface due to erosion and uplift, providing valuable insights into the geological history of an area.

In contrast, extrusive magma is erupted onto the surface, often resulting in fine-grained rocks like basalt. Volcanic refers more generally to processes associated with active volcanoes but does not specify the type of magma. Pyroclastic material consists of volcanic ash and debris expelled during explosive eruptions, which is distinct from the magma itself. Hence, the correct response highlighting the type of magma found stored within the crust is indeed intrusive.