what is shale contact metamorphosed into?

Answer 1

Although John's answer is correct it is not complete. Contact metamorphism commonly changes shale into hornfels. At lower temperature it becomes amphibole hornfels and at higher temperature it becomes pyroxene hornfels.

Answer 2

At low temperatures and pressures, shale metamorphoses into slate. At higher pressures, it becomes schist.

Answer 3

crude oil