Fig. 3

Thellier results plotted on Arai and Zijderveld (insets) diagrams for a upper clinker; b, c lava interior; d lower clinker, and e scoria. In both Arai and Zijderveld diagrams, lines were fitted according to modified TTA and curvature criteria (Leonhardt et al. 2004; Paterson et al. 2014). In Arai diagrams, numbers denote temperatures in \(^\circ\)C and open squares indicate partial thermoremanent magnetization checks. Zijderveld diagrams are shown in the sample coordinate projected onto the x-y (blue) and x-z (red) planes