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Table 2 Mineral assemblages of altered rock fragments in the volcanic ash

From: Mineralogical study on volcanic ash of the eruption on September 27, 2014 at Ontake volcano, central Japan: correlation with porphyry copper systems

Sample name Mineral assemblagesa Alterationb Colorc
Si Ab Kfs Kao Mus Pyl Alu Anh Pyr Chr Rul Pl Ano Px Bi Grt glass
141014 coarse-6 *    *      *    * * *    * Partly nd
Med3-4-7    *          *       Partly nd
Coase-1 *         *   *        RS OW
Coarse-11 *           *        RS OG
Coarse-18 *         *   *        RS Tr
Coarse-2 *    *      *          AA OW
Coarse-12 *    *    *   *          AA OW
Coarse-13 *    *      *          AA OG
Coarse-14 *       *   *          AA OG
Coarse-16 *      *    *          AA OG
Coarse-17 *      *    *          AA Tr
Coarse-4 *   *   *      *         Ser TBG
160223 Coarse 4-3 *     *     *          Ser OW
Coarse-6 * * *                PA TW
Med3-5-10   * *      *        *    PA nd
Med 1-2 *   *       *        *   PA nd
  1. aMineral names are abbreviated as: Si: silica mineral, Ab: albite, Kfs: potassic feldspar, Kao: 7 Å-kaolin-group mineral, Mus: muscovite, Pyl: pyrophyllite, Alu: alunite, Anh: anhydrite, Pyr: pyrite, Chr: chlorite, Rul: rutile, Pl: plagioclase, Ano: anorthoclase, Px: pyroxene, Bi: biotite, and Grt: garnet
  2. bPartly: partly altered volcanic rock; RS: residual silica; AA: advanced argillic; Ser: sericite; PA: potassic alteration
  3. cOW: opaque white-colored; OG: opaque gray-colored; TW: translucent white-colored; TBG: translucent brownish gray-colored; Tr: transparent; nd: no data