Explain how inclusions at the base of a lava flow can determine the relative age of the layers

As explained below.

Explanation:

Stratigraphy is the branch of geology that is concentrated on the composition and the structure of the layer of the earth's crust. The fundament of inclusions says that that the inclusion or fragment of another material, can occur bu when the matter must be older to the present flow.  As the lava tends to flow in the presence of the deposited material thus it follows the superimposition the base must get eroded if not then the lava will have to form inclusions.   The sils are cooled below the surface to form magma that forces itself through the cracks of other rocks. The above and below magma can be incorporated as inclusion. Para, Uni, and disconformity separate all these sedimentary rocks and thus the formation of inclusions takes place.

Mutations are changes in the dna