Phase: The construction phase for the Ishtar Gate bricks (see Table 1).

CCRIT (μT)/ (ZAm2): Results of analysis using the CCRIT criteria [42] in microtesla (Banc) and virtual axial dipole moment units (VADM). Uncertainty bounds for Banc are the range of values accepted by CCRIT (the ‘extended error bars’ of [46] and for the VADM values, uncertainties are 1σ calculated from the ‘best’ estimates from each specimen that produces the minimum scatter at the site level as is the practice in CCRIT. BiCEP (μT) / (ZAm2): same as CCRIT but using the BiCEP analysis [41]. Uncertainty bounds for μT are Bayesian credibility intervals (analogous to the extended error bars from CCRIT). For the VADM values, we use the 95% credibility range divided by four, which is analogous to 1σ uncertainties used by CCRIT.