How does radiometric dating work in the geologic time scale?

Radiometric dating is a technique used to determine the absolute age of rocks and minerals by measuring the abundance of radioactive isotopes and their decay products, which form at a constant rate. Combined with stratigraphic principles, these absolute age measurements help geochronologists establish the boundaries of the geologic time scale. Pioneers such as Ernest Rutherford and Bertram Boltwood laid the groundwork for this method in the early twentieth century.

What we know

• Radiometric dating compares the abundance of a naturally occurring radioactive isotope within a material to the abundance of its decay products. [2]
• Decay products form at a known constant rate of decay, allowing scientists to determine the absolute age of geological features. [2]
• Radiometric dating techniques are paired with stratigraphic principles in geochronology to precisely date the boundaries within the geologic time scale. [2, 3]
• Ernest Rutherford and Bertram Boltwood pioneered the radiometric dating of minerals and rocks between 1906 and 1907. [2]

Still open

• There is ongoing debate regarding the exact absolute ages of certain key events on the lunar geologic timescale because correlating regolith samples with lunar geological units is difficult and affected by heavy bombardment.

Where to go next

• how it workedWhat are the primary techniques used in geochronology?
• the bigger pictureHow does the geologic time scale use rock sequences?
• whoWho pioneered the dating of rocks using radioactivity?
• a case in pointHow is the lunar geologic timescale constrained?
• how we knowHow do magnetic signatures help date archaeological materials?
• an unexpected connectionHow do moon rocks help establish planetary timelines?Absolute ages for periods on the Moon's geologic timescale are constrained by applying terrestrial radiometric dating methods to samples obtained directly from the lunar surface.

Sources

• [1]radiometric dating (Wikidata Q214753) · CC0 1.0
• [2]Radiometric dating · CC BY-SA 4.0
• [3]Geologic time scale · CC BY-SA 4.0
• [4]Archaeomagnetic dating · CC BY-SA 4.0
• [5]Lunar geologic timescale · CC BY-SA 4.0