In richardjtelford/bio250: What the Package Does (One Line, Title Case)

library(learnr)
knitr::opts_chunk$set(echo = FALSE)

Software for calibrating radiocarbon dates

Web:

• calib

• OxCal

R packages

• rbacon
• Bchron
• oxcAAR (interface to OxCal)

Bchron is easiest to use. OxCal is very popular with archaeologists as it has models they can use.

Calibration dates

Exercise

Calibrate and plot the dates 2450 +/- 30 BP and 2600 +/- 30 BP measured on terrestrial leaves.

First, load the Bchron package. Function BchronCalibrate will calibrate individual dates. The most important arguments are ages, ageSds, and calCurves, which take the radiocarbon age, error, and the name of the calibration curve to use. Either a single value or a vector can be used for each argument, but all three must be the same length. The standard calibration curves are 'intcal20', 'shcal20' and 'marine20'.

library(Bchron)
cal <- BchronCalibrate(
  ages = , 
  ageSds = , 
  calCurves =     
)
summary(cal)
plot(cal)

cal <- BchronCalibrate(
  ages = c(2450, 2600), 
  ageSds = c(30, 30), 
  calCurves = rep("intcal20", 2))
summary(cal)
plot(cal)

1 Why are the calibrated dates' probability density functions so irregular?
2 Why do the two dates give such different shaped calibrated dates?
3 Calibrate the dates as if they are on marine fossils and compare the results.

richardjtelford/bio250 documentation built on Oct. 12, 2022, 2:16 a.m.