Age dating of basalt
Any two points in the universe lie on a straight line!
However, its exact value, and equally important its error estimate, cannot be stated with statistical confidence.
For BI (Lower lava) a descending age spectrum was used to arrive at a plateau age of 60.56 ± 0.29 Ma.
The MSWD value of ~ 15 (p (2001) used 12 steps to arrive at a “plateau age” of 58.48 ± 0.18 Ma.
An adjunct method of evaluation is to present the relevant data on an isotopic ratio plot and look for straight-line segments through three or more consecutive heating steps. The resultant “goodness of fit” parameter, in tandem with the number of points on the line, must be evaluated for statistical reliability (95% confidence level generally) using Chi Square Tables (, 1992).
If the data scatter badly around the best-fitting straight line, the resulting “age” should be rejected as being not reliable.
Search for age dating of basalt:
An easier method is to look at the data on age-spectrum plots and assess the reliability of “plateau” sections.