Fig. 5 Photographs of the normally graded lapilli tuff. (a) Outcrop photograph of the normally graded lapilli tuff. (b) Multiple normally graded divisions in the lower part of the the normally graded lapilli tuff with a gradational internal boundary (dashed line). (c) Large amounts of crystals (alkali feldspar and quartz) in the normally graded lapilli tuff. (d) Crude stratifications (arrows) defined by vertical alternation of coarse-rich and -poor layers in the normally graded divisions in the lower part of the normally graded lapilli tuff. (e) Fine-grained upper part of the normally graded lapilli tuff. (f) Microphotographs of the normally graded lapilli tuff. Fractured crystals with a jigsaw-fit texture (arrow) are noteworthy (Lfs: lithic fragments, Qtz: quartz).