Figure 9. Tera-Wasserburg disagrams showing U-Pb age data (error
ellipse=2 SE) for sample Baz 2 and HAB1 (A and B). Gray areas around
discordia represent 2 SE uncertainty of linear regression. Analytical
precision (age, initial 207Pb/206Pb)
is indicated as analytical uncertainty (first value, 1 sigma),
“studentized 100(1-α)% confidence interval for t using the appropriate
number of degrees of freedom” (second value) and “approximate
100(1-α)% confidence interval for t with over-dispersion, calculated as
z=y√MSWD” (value 3). MSDW=mean squared weighted deviations, n=numbers
of spot analyses. The U-Pb data ellipses are color-coded according to
their 238U/206Pb value, displayed in
the individual color scales at the right margin of the diagrams. Data
points plotting to the left of the concordia were excluded from age
regression; some outliers were also excluded, which plotted off the main
regression line, without altering the original age estimate, but
improving precision and MSWD values. Graphic presentation and age
calculation utilized IsolpotR (Vermeesch, 2018).
Table 3. Sample details with U-Pb age results