Fig. 2: Example 40Ar/39Ar age spectra, weighted kernel density estimations (WKDEs), and inverse isochrons.
From: 40Ar/39Ar dating reveals over 30 million years of plume-ridge interaction formed the Rio Grande Rise
a NBP1808-D26-27 is a sample where the traditional age plateau is preferred and (b) NBP1808-D06-18 is a sample where the WKDE is preferred, an example of an experiment that has increased scatter resulting in a high MSWD ( > 50, and much higher than the MSWDmax = 1.78) and an unrealistically low weighted mean age plateau uncertainty of ± 0.83 Ma (2σ standard error). The WKDE 2.5% and 97.5% confidence intervals (blue dotted lines) do a better job of capturing this sample’s uncertainty ( + 3.49, −4.40 Ma), and all the individual steps fall inside this range. The magenta line denotes the ArArCALC weighted mean age and its height the weighted mean plateau age 2σ standard error.
