Relative dating sequence of events is dating a guy 10 years older bad
The age of formations is marked on a geologic calendar known as the geologic time scale.
Similarly, in geology, if distinctive granitic pebbles can be found in the sediment beside a similar granitic body, it can be inferred that the granite, after cooling, had been uplifted and eroded and therefore was not injected into the adjacent rock sequence.
Although with clever detective work many complex time sequences or relative ages can be deduced, the ability to show that objects at two separated sites were formed at the same time requires additional information.
Superposition: The most basic concept used in relative dating is the law of superposition.
Simply stated, each bed in a sequence of sedimentary rocks (or layered volcanic rocks) is younger than the bed below it and older than the bed above it.
The most useful indication of time equivalence is similar fossil content, provided of course that such remains are present.