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Table 5 Major element compositions of volcanic glass shards

From: Historical and paleo-tsunami deposits during the last 4000 years and their correlations with historical tsunami events in Koyadori on the Sanriku Coast, northeastern Japan

  SiO2 TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O n Totala
ONM-GS1-0.42 77.0 0.4 12.7 1.8 0.1 0.4 2.1 4.1 1.4 15 97.5
Ishimura et al. (2014) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.0   0.6
NTR-Br-34.93 77.0 0.4 12.8 1.8 0.1 0.4 2.1 4.1 1.4 15 96.1
Ishimura et al. (2014) 0.3 0.1 0.2 0.1 0.1 0.0 0.1 0.3 0.1   0.7
To-a (35) 77.50 0.36 12.73 1.62 0.09 0.38 1.81 3.90 1.37 19 98.41
Aoki and Machida (2006) 0.7 0.0 0.4 0.2 0.0 0.1 0.2 0.1 0.1   1.4
To-a (36) 77.69 0.36 12.74 1.66 0.09 0.35 1.80 3.99 1.31 8 98.53
Aoki and Machida (2006) 0.6 0.1 0.3 0.1 0.0 0.0 0.1 0.2 0.0   1.3
To-a (37) 76.17 0.42 13.41 1.89 0.09 0.38 1.99 4.08 1.56 18 92.89
Aoki and Machida (2006) 0.3 0.0 0.2 0.1 0.0 0.0 0.1 0.1 0.1   1.1
KYD-TrW sec. 2 20–25 cm 77.1 0.4 12.7 1.8 0.1 0.4 2.1 4.1 1.4 15 94.4
(This study) 0.3 0.1 0.2 0.2 0.1 0.0 0.0 0.1 0.1   1.3
  1. Number on upper line shows a mean value and that on lower line shows a standard deviation. Measured values are recalculated to 100 % on a water-free basis. Results of Aoki and Machida (2006) are shown for comparison and numbers in brackets show sample number in the reference
  2. aRaw data before recalculations