Fig. 2: The relationship between palaeointensity and TiO2 wt% in lunar Apollo samples.
From: An intermittent dynamo linked to high-titanium volcanism on the Moon
a, Palaeointensity as a function of TiO2 wt% from existing data (Supplementary Table 1). Black circles represent mean palaeointensity and maximum reported TiO2 wt% in the literature (Supplementary Table 1). Error bars represent 1σ uncertainty. Palaeointensity measurements reported without uncertainty have been excluded. Bold black line represents two-sided weighted linear regression and 95% confidence interval (black dashed line). Blue horizontal line represents weighted mean palaeointensity value for low-Ti (<6 wt% TiO2) basalts. Red horizontal line represents weighted mean palaeointensity value for high-Ti (>6 wt% TiO2) basalts. Shaded regions represent precision on mean value for each group. Histograms show the distribution of palaeointensity measurements for low- and high-Ti basalts in blue and red, respectively. b, A correlation matrix for Pearson’s correlation coefficient, r, for palaeointensity, TiO2 wt%, Mg#, K2O wt%, Sm/Nd ratio, age and magnetic hysteresis parameters Mrs/Ms and Hcr/Hc for all lunar basalts for which palaeointensity and/or magnetic hysteresis measurements exist. The only strong correlations (r > 0.5) are between TiO2 wt%, age and palaeointensity.
