Dating Methods
Radiometric dating, tree rings, ice cores, varves, and how independent methods agree.
8 articles
Radiation-Based Methods
- Radiometric DatingIsochrons, concordia plots, and cross-method agreement address the standard objections to radiometric dating.
- Radiocarbon DatingCarbon-14 dating is calibrated against tree rings and varves, and is limited to roughly the last 55,000 years.
- Luminescence DatingOptically stimulated luminescence dates when sediment was last exposed to light, using no parent-daughter ratio.
Annual Layer Counting
- DendrochronologyOverlapping tree-ring sequences give an unbroken annual record extending more than 12,000 years.
- Ice CoresAnnual layers in Greenland and Antarctic ice are counted directly and reach back beyond 100,000 years.
- VarvesAnnual lake sediment layers provide a countable record independent of any radioactive decay.
- Coral BandingMassive corals deposit one density couplet per year, and the same skeleton can be dated independently by uranium-thorium.