Fig. 1: Overview of AT-eruption products.
From: Magma chamber decompression during explosive caldera-forming eruption of Aira caldera
a Distribution of products of the AT eruption. Inset shows the location of the Aira caldera. The solid red line indicates the topographic rim of the Aira caldera, broken blue lines are the isopach lines that represent the thickness of the Osumi pumice fall deposit, and the pink-colored area represents the distribution area of Ito ignimbrite. Orange circles with labels “O”, “T”, “I”, and “A” show the sampling locations of the Osumi pumice deposit, Tsumaya pyroclastic flow deposit, Ito ignimbrite, and the AT ash fall deposit, respectively. b Schematic stratigraphy of the eruptive products of the AT eruption showing sampling depths. c Optical microscopic image of glass embayments in a quartz phenocryst of the Osumi pumice fall deposit (sample id: 140901F8). This microphotograph was taken through a polished surface of a quartz phenocryst embedded in epoxy resin, showing the glass embayments on the crystal surface of the quartz. Labels “g” indicate representative glass embayments. Labels “b” show the bubbles in glass embayments. d Backscattered electron image of a quartz phenocryst (Qz) with several glass embayments (g) found in a quartz phenocryst from the Osumi pumice fall deposit (sample id: 171129C2). e Distribution of water content in the glass embayment and surrounding groundmass glasses. The colored circles indicate the analysis point and the color of each circle represents the quantified water content at each analysis point.
