An intrusion of magma along a bedding plane is called

An intrusion of magma along a bedding plane is called a "sill". A sill is a horizontal sheet-like intrusion of magma that is injected into the layers of sedimentary or volcanic rocks. When magma is forced into a horizontal crack or bedding plane between layers of rock, it solidifies and forms a flat, tabular sheet of rock parallel to the layering of the surrounding rocks. Sills can vary in thickness from a few centimeters to hundreds of meters and can be found in various geological settings such as mountain ranges, volcanic areas, and rift valleys. Sills are different from dikes, which are vertical sheet-like intrusions of magma that cut across the layers of rock.