EVERYDAY SCIENCE

Detailed explanation-1: -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 the geologic time scale to illustrate the order in which events on Earth have happened. The geologic time scale was developed after scientists observed changes in the fossils going from oldest to youngest sedimentary rocks.

Detailed explanation-3: -The law of superposition is one of the principles of geology scientists use to determine the relative ages of rock strata, or layers. This principle states that layers of rock are superimposed, or laid down one on top of another. The oldest rock strata will be on the bottom and the youngest at the top.

Detailed explanation-4: -The Phanerozoic Eon is divided into three eras, the Paleozoic, Mesozoic and Cenozoic eras. These were named for the kinds of fossils that were present. The Cenozoic is the youngest era and the name means “new life”. This is because the fossils are similar to animals and plants that are common today.

Detailed explanation-5: -Relative time ("chronostratic")–subdivisions of the Earth’s geology in a specific order based upon relative age relationships (most commonly, vertical/stratigraphic position). Absolute time ("chronometric")–numerical ages in “millions of years” or some other measurement.