Methods of dating archaeological findings

27-Jul-2017 08:21

When it comes to determining the age of stuff scientists dig out of the ground, whether fossil or artifact, “there are good dates and bad dates and ugly dates,” says paleoanthropologist John Shea of Stony Brook University.

The good dates are confirmed using at least two different methods, ideally involving multiple independent labs for each method to cross-check results.

After archaeologists have thoroughly surveyed the site they begin excavation. Then archaeologists excavate the site using trowels, shovels, and various other tools.

Tephrochronology: Within hours or days of a volcanic eruption, tephra — fragments of rock and other material hurled into the atmosphere by the event — is deposited in a single layer with a unique geochemical fingerprint.

Artifacts can also be dated using dendrochronology, which uses the annual growth rings in trees to establish an age for artifacts.

Artifacts can also be dated using radiocarbon dating.

Biostratigraphy: One of the first and most basic scientific dating methods is also one of the easiest to understand.

Layers of rock build one atop another — find a fossil or artifact in one layer, and you can reasonably assume it’s older than anything above it.

Tephrochronology: Within hours or days of a volcanic eruption, tephra — fragments of rock and other material hurled into the atmosphere by the event — is deposited in a single layer with a unique geochemical fingerprint.Artifacts can also be dated using dendrochronology, which uses the annual growth rings in trees to establish an age for artifacts.Artifacts can also be dated using radiocarbon dating.Biostratigraphy: One of the first and most basic scientific dating methods is also one of the easiest to understand.Layers of rock build one atop another — find a fossil or artifact in one layer, and you can reasonably assume it’s older than anything above it.Paleomagnetism: Earth’s magnetic polarity flip-flops about every 100,000 to 600,000 years.