The use of IntCal13 and post-bomb curves in one calibration

[Lior Regev]

Dear all,

 

I have samples of 95-99pMC, that require the use of both IntCal13 and post-bomb curves together.

How can I calibrate such dates in OxCal using both ‘IntCal13’ and ‘Bomb 13 NH2’ curves?

 

Thanks a lot and happy new year!

Lior

 

Dr. Lior Regev

D-REAMS Radiocarbon Laboratory

Max Planck - Weizmann Institute Center for Integrative Archaeology and Anthropology

Weizmann Institute of Science

Mobile: +972-52-5386031

Office: +972-8-9345169

Fax: +972-8-9345170

 

[Christopher Ramsey]

You can switch curve during the calibration. Also the bomb curve includes the atmospheric IntCal13 back to AD1650 so there is an overlap. The following would switch between curves mid series:

Plot()
{
Curve("IntCal13","IntCal13.14c");
R_F14C(0.95, 0.002);
R_F14C(0.96, 0.002);
R_F14C(0.97, 0.002);
R_F14C(0.98, 0.002);
Curve("Bomb13NH1","Bomb13NH1.14c");
R_F14C(0.99, 0.002);
R_F14C(1.00, 0.002);
R_F14C(1.01, 0.002);
};

If you need to switch back and forth you can use cross referencing as in:

Plot()
{
Curve("IntCal13","IntCal13.14c");
Curve("Bomb13NH1","Bomb13NH1.14c");
Curve("=IntCal13");
R_F14C(0.95, 0.002);
Curve("=Bomb13NH1");
R_F14C(0.99, 0.002);
Curve("=IntCal13");
R_F14C(0.96, 0.002);
Curve("=Bomb13NH1");
R_F14C(1.00, 0.002);
Curve("=IntCal13");
R_F14C(0.97, 0.002);
Curve("=Bomb13NH1");
R_F14C(1.01, 0.002);
Curve("=IntCal13");
R_F14C(0.98, 0.002);
};

You might want to use higher than normal resolution for this sort of chronology too.

Best wishes

Christopher

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[Lior Regev]

Thank you Christopher, it helps a lot. Please note that when calibrating R_F14C values of 0.972-0.974, the 2 sigma range is not complete in either curve. Is it possible to add another ~30-50 years to the Bomb Curve (so it will start at around 1600-1620AD)? I think it should fix it.

All the best,
Lior