GEOLOGY

Detailed explanation-1: -To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

Detailed explanation-2: -Scientists use two approaches to date rocks and fossils. Relative age dating is used to determine whether one rock layer (or the fossils in it) are older or younger than another base on their relative position: younger rocks are positioned on top of older rocks.

Detailed explanation-3: -Superposition of rock units is a very simple and straightforward method of relative age determination. The principle states that in a sequence of undeformed sedimentary rocks the oldest beds are at the bottom and the youngest ones are at the top.

Detailed explanation-4: -Relative age refers to the approximate age of a specific rock layer. It is determined by comparing its position to other rock layers. The process used to establish whether a rock layer or a geologic event is older or younger than the other without knowing their specific ages is called relative dating.