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Table 4 Results of XRF (bulk chemistry) of ashfall, rain-triggered lahar and ROS-triggered lahar deposits, and pre-eruptive fluvial deposits

From: Lahar characteristics as a function of triggering mechanism at a seasonally snow-clad volcano: contrasting lahars following the 2014 phreatic eruption of Ontake Volcano, Japan

Lithology Sample name SiO2 (wt%) TiO2 Al2O3 Fe2O a3 MnO MgO CaO Na2O K2O P2O5 SO b3 Others Total
FP method for sediments analyzed by Rigaku RIX 1000
 September 2014 primary deposits
  Ashfall On-1 57.03 0.87 16.46 5.62 0.03 0.53 1.37 1.11 2.12 0.30 14.29 0.25 100.00
  Ash could deposits On-44 56.13 0.61 14.65 5.31 0.04 1.12 4.18 1.29 1.90 0.36 14.23 0.19 100.00
 October 2014 rain-triggered lahar (Cohesive debris flow) deposits
  Muddy On-2 56.77 0.95 15.24 6.12 0.05 0.91 3.16 1.07 2.27 0.37 12.90 0.19 100.00
  Muddy On-3 55.40 1.03 13.68 7.12 0.06 0.89 3.62 1.72 2.07 0.33 13.91 0.18 100.00
  Muddy On-4 58.66 0.93 15.45 5.49 0.05 0.95 3.20 1.17 2.21 0.36 11.34 0.18 100.00
  Muddy On-5 59.62 0.97 13.38 6.24 0.04 0.64 2.95 1.11 1.92 0.29 12.66 0.18 100.00
  Muddy On-6 57.80 1.07 14.46 6.80 0.08 1.20 3.65 1.94 2.16 0.32 10.34 0.18 100.00
  Muddy On-13 57.89 0.88 15.36 5.94 0.06 0.99 3.43 1.38 2.31 0.29 11.26 0.21 100.00
  Muddy On-18 58.16 0.96 15.45 5.43 0.05 0.88 2.68 1.49 2.25 0.36 12.11 0.18 100.00
  Muddy On-34 57.57 0.87 15.98 5.73 0.05 0.97 3.15 1.47 2.20 0.36 11.49 0.16 100.00
  Muddy On-45 56.90 0.80 15.50 5.51 0.06 1.03 3.33 1.37 2.10 0.32 12.79 0.28 100.00
 April 2015 rain-on-snow-triggered lahar deposits
  Sandy On-16 61.05 1.00 15.66 5.90 0.09 1.10 4.29 1.82 2.41 0.29 6.21 0.18 100.00
  Sand-gravel On-19 65.65 0.91 15.53 4.55 0.07 0.67 3.32 1.76 2.73 0.33 4.31 0.17 100.00
  Sandy On-26 64.92 0.64 16.67 4.72 0.11 1.00 5.05 2.89 2.95 0.29 0.62 0.14 100.00
  Sand-gravel On-51 60.26 1.06 14.80 5.85 0.06 1.00 3.20 2.07 2.58 0.28 8.65 0.19 100.00
 April 2015 rain-on-snow-triggered lahar deposits (mud drape)
  Muddy On-21 57.75 0.77 18.31 5.81 0.03 1.09 1.58 1.10 2.20 0.53 10.69 0.15 100.00
 Pre-eruptive fluvial deposits
  Sandy On-7 61.90 1.14 15.80 6.85 0.14 1.31 5.25 2.44 2.60 0.36 2.08 0.15 100.00
  Sandy On-11 63.89 0.97 16.07 5.87 0.11 1.08 4.99 2.28 2.63 0.34 1.58 0.20 100.00
  Sandy On-17 65.68 0.78 15.45 5.27 0.11 0.97 4.15 2.38 3.03 0.37 1.65 0.16 100.00
  Sandy On-22 66.35 0.67 15.68 4.73 0.10 0.98 4.71 2.97 3.14 0.27 0.27 0.14 100.00
  Sand-gravel On-33 66.57 0.99 15.34 4.44 0.08 0.90 3.80 1.82 2.75 0.28 2.83 0.20 100.00
  Sand-gravel On-43 64.38 1.01 15.67 4.90 0.08 0.99 4.01 1.65 2.63 0.36 4.11 0.21 100.00
 Shirakawa deposits
  Muddy On-23 61.81 0.70 15.06 5.18 0.05 0.98 2.97 1.55 2.34 0.27 8.94 0.16 100.00
  Sandy On-24 60.73 0.78 16.08 5.36 0.07 0.99 3.92 2.38 2.45 0.43 6.66 0.16 100.00
Sample name As (ppm) Ba Co Cr Cu Nb Ni Pb Sr V Zn Total
Calibration method for sediments analyzed by Rigaku RIX 2000
 September 2014 primary deposits
   On-1 24 475 16 37 13 8 10 13 528 198 72 1654
   On-44 15 495 13 36 15 8 8 16 551 127 100 1652
 October 2014 rain-triggered lahar (Cohesive debris flow) deposits
   On-2 16 462 17 36 12 8 10 10 540 200 73 1636
   On-3 15 487 16 39 13 9 8 12 546 195 85 1685
   On-4 12 457 14 62 12 8 13 12 545 190 72 1659
   On-5 16 425 17 36 13 9 11 12 531 184 75 1591
   On-6 14 482 17 36 11 10 10 10 557 202 83 1690
   On-13 14 479 15 34 12 9 9 11 533 182 70 1627
   On-18 13 463 13 34 10 9 7 12 532 193 55 1614
   On-34 15 456 12 33 12 9 8 13 547 188 66 1635
   On-45 16 473 15 35 14 9 12 11 546 187 78 1645
 April 2015 rain-on-snow-triggered lahar deposits
   On-16 10 468 13 34 10 10 11 11 590 185 75 1669
   On-19 8 529 8 28 9 9 8 13 529 165 61 1659
   On-26 3 554 9 27 8 9 8 13 603 119 77 1697
   On-51 12 488 12 34 12 9 10 11 550 202 59 1673
 April 2015 rain-on-snow-triggered lahar deposits (mud drape)
   On-21 21 508 13 33 13 8 8 16 572 195 68 1727
 Pre-eruptive fluvial deposits
   On-7 6 489 13 35 9 11 11 10 564 213 96 1732
   On-11 5 511 10 28 9 9 9 12 597 182 77 1712
   On-17 5 566 9 28 7 10 10 12 533 155 75 1704
   On-22 3 591 11 26 7 11 10 14 546 122 82 1731
   On-33 7 520 9 30 6 10 8 11 507 188 65 1663
   On-43 8 496 10 31 9 10 10 10 546 200 67 1668
 Shirakawa deposits
   On-23 10 503 8 27 9 8 6 13 527 110 54 1529
   On-24 9 519 9 29 11 8 8 13 579 143 66 1655
  1. aTotal iron oxide as Fe2O3; btotal sulfur as SO3