What is the term for an igneous intrusion that is forced between two layered rock units, typically creating a dome on the surface?

What is the term for an igneous intrusion that is forced between two layered rock units, typically creating a dome on the surface?

• A. Caldera
• B. Laccolith
• C. Glacier
• D. Inactive volcano

Answer: (B)

The term for an igneous intrusion that is forced between two layered rock units and typically creates a dome on the surface is a laccolith. A laccolith forms when magma intrudes into sedimentary rock layers, pushing them upwards, which creates a dome-shaped structure. This characteristic shape results from the pressure of the molten rock filling the space while solidifying, causing the overlying strata to deform. In contrast, a caldera is a large depression formed after a volcanic eruption when the magma chamber below the volcano empties and causes the ground to collapse. A glacier refers to a large, slow-moving mass of ice formed by compacted snow. An inactive volcano is one that has not erupted in a considerable period but does not refer to the specific geological formation seen with laccoliths.

The term for an igneous intrusion that is forced between two layered rock units and typically creates a dome on the surface is a laccolith. A laccolith forms when magma intrudes into sedimentary rock layers, pushing them upwards, which creates a dome-shaped structure. This characteristic shape results from the pressure of the molten rock filling the space while solidifying, causing the overlying strata to deform.

In contrast, a caldera is a large depression formed after a volcanic eruption when the magma chamber below the volcano empties and causes the ground to collapse. A glacier refers to a large, slow-moving mass of ice formed by compacted snow. An inactive volcano is one that has not erupted in a considerable period but does not refer to the specific geological formation seen with laccoliths.