Answer:
Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence. The method of reading the order is called stratigraphy (layers of rock are called strata). Relative dating does not provide actual numerical dates for the rocks.
A type of rock formed after the deposition, compaction and cementation of sedimentary material produced by either the weathering and erosion of the Earth’s surface, biological organisms (shells) or chemical precipitation (ooids). Examples of sedimentary rocks are sandstone, mudstone, limestone and coal.
Rocks are normally laid down in order, one on top of another. In a sequence, the oldest is at the bottom, the youngest is at the top. This is the principle of ‘superposition’.
