Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event. Second, it is possible to determine the numerical age for fossils or earth materials.

How are cross cutting relationships used in relative dating?

The Principle of Cross-Cutting Relationships states that rock formations that cut across other rocks must be younger than the rocks that they cut across. Geologists find the cross-cutting principle especially useful for establishing the relative ages of faults and igneous intrusions in sedimentary rocks.

How do geologists determine the age of rocks?

The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.

What are different methods of dating rocks?

Determining the numerical age of rocks and fossilsName of MethodAge Range of ApplicationRadiocarbon1 - 70,000 yearsK-Ar dating1,000 - billion of yearsUranium-Lead10,000 - billion of yearsUranium series1,000 - 500,000 years7 more rows