The correct answer for the question that is being presented above is this one: "C. if it was a sill, both shale beds would be metamorphosed where they came in contact with the basalt." Based on the cross-cutting nature of contact metamorphism, a basalt layer between two shale beds was a lava flow or a sill is that if it was a sill, both shale beds would be metamorphosed where they came in contact with the basalt
