Answer:
17. Laccolith
18. Sill
Step-by-step explanation:
A laccolith is formed when magma makes its way up a d-ike and lodges itself between sedimentary rocks. The successive flow puts pressure on the rock such that a dome like structure is formed.
Sills are like mini laccoliths but instead are much smaller and linear. They can appear on multiple layers as shown in the diagram above.