Calculating ΔR from a marine sample whose year of collection is known involves 2 steps:
  1. Intersect the calendar year of collection with the marine calibration curve and determine the corresponding 14C age (reverse-calibrate).
  2. Subtract the reverse-calibrated collection year from the mean of the 14C age of the marine sample
The uncertainty of ΔR is the uncertainty of the marine sample 14C measurement