After the data form has been filled in, press the "Enter Data" button to
enter the data in the text box at the bottom of the page. Alternatively,
paste data from a spreadsheet program into the text box. There is a sample
counter which shows how many samples have been added to the text box. When
Sample entry is complete press the "Calibrate" button to perform the calibration
of the sample data.
Marine calibration has changed with the release of Marine20. The modern global ocean age is now modelled at
about 550 years instead of 400 years. ΔR values calculated before August 2020 must be recalculated from the updated database at http://calib.org/marine
INTCAL20 calibration is limited to 199-50,100 14C year BP. This dataset is
recommended for most non-marine samples. From 0-14190 cal BP it is based on
dendro-dated tree-ring 14C measurements. Beyond 14.19ka it is based on marine coral,
varve data, and floating tree rings. Details of the dataset construction are given in
Radiocarbon Vol. xx, 2020, pp xxxx-yyyy.
MARINE20 calibration is limited to 603-50,788 14C year BP. This datset is
recommended for most marine samples. It is based
on a computer model of the ocean carbon exchange that used INTCAL20 input.
Details of the dataset construction are given in
Radiocarbon Vol. xx, 2020, pp xxxx-yyyy.
SHCAL20 calibration is limited to 191-50,134 14C year BP. The Southern Hemisphere
dataset is based on treerings with an average offset of 43±13 years from the
INTCAL20 dataset. In time periods where southern hemisphere tree rings are not available
a random effects model was used to take account of the fact that the offset may vary
slowly over time. Details of the dataset construction are given in
Radiocarbon Vol. xx, 2020, pp xxxx-yyyy.
This field must be unique for each sample entered. If you forget to change
it you may not be able to tell your samples apart in the multisample plots.
Certain characters are forbidden in samples codes because of requirements
imposed by the underlying operating system. Those characters include & / and '
For samples drawing carbon from two reservoirs, mixed curves are constructed
using a linear combination of calibration curves for the two reservoirs.
The combination of the reservoirs is based on your estimate of how much each
contributed (%)