Influence of the crust and crustal structure on the location and composition of high‐alumina basalts of the Taupo Volcanic Zone, New Zealand

摘要: Abstract High‐alumina basalts (HABs) that occur throughout the central part of Taupo Volcanic Zone (TVZ) are associated particularly with faulting, and many where faults intersect caldera margins. For convenience, described in terms three geographic‐tectonic segments: Okataina north, Kapenga middle, south. Evidence for mixing mingling between rising basaltic magmas rhyolitic rocks is common, including frequent occurrence xenocrysts xenoliths, quench textures, melting around rims inclusions. Chemically, similar major element compositions, suggesting relatively homogeneous PT conditions mantle source, but variation some trace elements suggests different processes operating crust variable degrees contamination. The model presented HAB generation TVZ partial peridotite upper mantle, melt int...