Relative age dating geology
This also applies to rocks, minerals, and derivative materials (such as sediments and soil).
The chemical composition of Earth's crust has similarities with other stony planets, with silicate-rich rocks being dominant in most locations on the surface.
Geologists draw on it and other basic principles ( to determine the relative ages of rocks or features such as faults.
Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free.
These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.
As these changes have occurred, organisms have evolved, and remnants of some have been preserved as fossils.
Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.
Stratigraphy is a branch of geology that studies rock strata with an emphasis on distribution, deposition, age and evidence of past life.
Search for relative age dating geology:
Once Steno recognized that the fossils he was contemplating (sharks teeth and sea shells) were formed in the sediments of oceans he was able to work out the basic rules of stratigraphy.