Relative dating principles include
The order of events in the archaeological cross section shows that the oldest remains are Roman.
After this the medieval remains are more recent and the industrial remains are more recent still.
Therefore, the actual length of geologic time represented by any given layer is usually unknown or, at best, a matter of opinion.
William Smith's collecting and cataloging fossil shells from rocks led to the discovery that certain layers contained fossils unlike those in other layers (see: fossil sorting).
After the uplift of the land, the forces of erosion attacked the highlands and the eroded rock debris was transported and redeposited in the lowlands.
Because fossils are believed to record the slow but progressive development of life, geologist use them to identify the relative age of rocks throughout the world.Relative dating is a dating method that used to determine determine the relative ages of geologic strata, artifacts, historical events, etc.This technique does not give specific ages to items.Wide rings are produced during wet years and narrow rings during dry seasons.This technique has posed a different problem for creationists, as this dating method does not make use directly of accelerated decay.