Fig. 10From: Petrographic and geochemical analyses to characterise the source of built historical natural stones — a case study of the volcanic stones from historical quarries and Baoguosi Temple in the city of Ningbo, ChinaDiagram of selected samples. a: Total alkali-SiO2 (TAS) diagram (Source: the authors, after Le Bas et al. 1986). b: Zr/TiO2-Nb/Y diagram (Source: the authors, after Winchester and Floyd 1977)Back to article page