A student wonders if shale and sandstone can be classified as igneous, metamorphic, or sedimentary. Which information will best help the students answer this question?
A.
the size and alignment of the shale and sandstone crystals
B.
the types of minerals found in shale and sandstone
C.
the places where shale and sandstone are found
D.
the processes that cause shale and sandstone to form
D. the processes that cause shale and sandstone to form
Understanding the processes that lead to the formation of shale and sandstone will help the student determine whether they can be classified as igneous, metamorphic, or sedimentary rocks. Shale and sandstone are both sedimentary rocks, formed through the accumulation and compaction of sediments. Igneous rocks form from the cooling and solidification of magma or lava, while metamorphic rocks form from the transformation of existing rocks under high temperature and pressure. By knowing the formation processes of shale and sandstone, the student can classify them correctly.