Igneous intrusions, or plutons, are bodies of magma that cool and solidify beneath the Earth's surface. They are classified based on their size, shape, and relationship to the surrounding 'country rock' they intrude into. A key distinction is whether they are concordant (parallel to existing layers) or discordant (cutting across existing layers).
Step 1: Understanding the Question:
The question is asking for the name of a sheet-like (tabular) igneous body that has been injected between, and parallel to, the layers of the surrounding rock.
Step 2: Detailed Explanation:
Let's define the given terms:
Dyke: A tabular intrusion that cuts across the bedding planes of the country rock (discordant).
Sill: A tabular intrusion that runs parallel to the bedding planes of the country rock (concordant).
Laccolith: A dome-shaped (or mushroom-shaped) concordant intrusion that has arched the overlying rock layers upwards.
Batholith: A very large, irregularly shaped, and deep-seated discordant intrusion.
The description "tabular" and "parallel to the bedding planes" perfectly matches the definition of a Sill.
Step 3: Final Answer:
The correct name for this type of intrusion is a Sill.