Question

contact metamorphism is mainly caused by...
pressure.
heat and pressure.
heat.
large amounts of force over a very large area.

Explanation:

Contact metamorphism occurs when rocks are in contact with a magma intrusion. Heat from the magma is the main agent that causes changes in the surrounding rocks, altering their mineralogy and texture. Pressure has a secondary role compared to heat in contact - metamorphism.

Answer:

heat.