What AMS Radiocarbon Dating Actually Does

Before getting to the specific dates, it is worth explaining what accelerator mass spectrometry radiocarbon dating actually is and how it produces the numbers that appear in the archaeological literature — because those numbers are often misunderstood, and the difference between “radiocarbon years BP” and “calibrated calendar years BP” matters significantly for the Bluefish Caves story.

Radiocarbon dating is based on the radioactive decay of carbon-14, a naturally occurring isotope of carbon that is produced in the upper atmosphere by cosmic ray bombardment.

Carbon-14 is incorporated into living organisms through the food chain — all living things contain carbon-14 at approximately the same ratio to the more abundant stable isotopes of carbon (carbon-12 and carbon-13).