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Table 1 Minerals in the volcanic ash of the 2014 eruption at Ontake volcano

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

Fraction Qtz Crt Trd Fsp Smct Opx Mica Pyl Kao Pyr Alu Anh Gyp
Bulk *** ** f ** f *** f f * * *** f **
Coarse *** *** * ** f *** f f * *** * f *
Medium *** ** f *** f   f f *** ** ** *** *
Fine *** f    ** f ** f *** f ***   ***
  1. The minerals are: Qtz: quartz, Crt: cristobalite, Trd: tridymite, Fsp: feldspars, Smct: smectite, Opx: orthopyroxene, mica: mica minerals, Pyl: pyrophyllite, Kao: 7 Å-kaolin-group mineral, Pyr: pyrite, Alu: alunite, natroalunite and minamiite, Ahd: anhydrite, and Gyp: gypsum
  2. The intensities of X-ray peaks in the XRD analysis are shown as: *** intense; ** weak; * minor; f: faint and blank none