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. 2015 Oct 1;112(41):E5558–E5559. doi: 10.1073/pnas.1517735112

Fig. 1.

Fig. 1.

Photos and thin section images in Plane Polarized Light (PPL) and Crossed Polars (XPL) of samples from the volcanic deposit layer at Kekeya section. To better compare our evidence with that of ref. 3, we follow their layer division. (A) Photo showing outcrop of volcanic tuff/lahar and sample locations. (B) Photo of tuff layer II and layer III showing cracks (but no cross-bedding, as claimed by ref. 3). (C and D) Thin section images in PPL (C) and XPL (D) of sample YC12-13-5, showing abundant vitric fragments and cracked crystal fragments, typical of volcanic origin. (E and F) Thin section images in PPL (E) and XPL (F) of sample YC12-13-6, showing vitric fragments, sanidine, and contorted biotite, typical of volcanic origin. (G and H) Thin section images in PPL (G) and XPL (H) of sample YC12-13-9, showing vitric fragments, sanidine, and contorted biotite, typical of volcanic origin. (I and J) Thin section images in PPL (I) and XPL (J) of sample YC12-13-7, showing minor (but still present) vitric fragments and abundant carbonate cements, likely indicating more-terrigenous clastic compositions. However, aegirine−augite, a characteristic mineral in the above three samples, and contorted biotite can also be found in YC12-13-7, which suggests the presence of volcanic components in this sample.