Fig. 7From: The marine conservation deposits of Monte San Giorgio (Switzerland, Italy): the prototype of Triassic black shale LagerstättenClassification of marine conservation deposits using a variation–covariation principal components analysis and the characterization of the Besano Formation of Monte San Giorgio (red margin). Data are listed in Tables 1 and 2. Modified after Frey et al. (2019). Note that among Triassic deposits, Monte San Giorgio, the Paris biota (Thaynes Fm) and Polzberg (Lunz Fm) are the only ones plotting close to the classic Black Shale Lagerstätten in A. A PCA 1 and 2; B PCA 2 and 3Back to article page