Relative dating in geology definition
It is a less advanced technique when compared to absolute dating.Some methods used in relative dating are stratigraphy, biostratigraphy, and cross dating.The main difference between absolute and relative dating is that the absolute dating is a technique to determine the numerical age of a rock or a fossil whereas the relative dating is a technique that determines the relative age.Furthermore, absolute dating can be done with the use of radiometric dating while relative age is determined with respect to other layers.The absolute dating refers to a technique used to determine the exact age of the artefact or a site using methods such as carbon dating while relative dating refers to a technique used to determine which object or item is older in comparison to the other one.Absolute dating determines the numerical age while relative dating arranges the fossils in an order.
Original horizontality: The principle of original horizontality states that layers of sediment, when first deposited, are fairly horizontal because sediments accumulate on surfaces of low relief (such as floodplains or the sea floor) in a gravitational field.
If sediments were deposited on a steep slope, they would likely slide downslope before they could be buried and lithified.
With this principle in mind, geologists conclude that examples of folds and tilted beds represent the consequences of deformation after deposition.
For example, a conglomerate containing pebbles of basalt is younger than the basalt, and a sill containing fragments of sandstone must be younger than the sandstone.
Geologists apply geologic principles to determine the relative ages of rocks, structures, and other geologic features at a given location.