tephra SiO2 TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O total Ref Hekla 4 Tephra 74.41 0.71 12.03 2.99 0.10 0.54 2.06 2.92 2.63 98.39 1794 Hekla 4 Tephra 73.09 0.80 12.32 3.43 0.08 0.68 2.50 2.70 2.52 98.12 1794 Hekla 4 Tephra 73.01 0.76 12.51 3.57 0.09 0.76 2.54 2.86 2.44 98.54 1794 Hekla 4 Tephra 72.97 0.80 12.25 3.54 0.08 0.66 2.61 3.21 2.65 98.77 1794 Hekla 4 Tephra 72.72 0.85 12.50 3.64 0.04 0.77 2.69 3.70 2.54 99.45 1794 Hekla 4 Tephra 72.44 0.85 12.24 3.69 0.09 0.79 2.73 3.25 2.48 98.56 1794 Hekla 4 Tephra 72.43 0.72 12.00 3.30 0.06 0.70 2.40 2.52 2.47 96.60 1794 Hekla 4 Tephra 72.05 0.70 12.37 3.80 0.10 0.79 2.85 3.33 2.40 98.39 1794 Hekla 4 Tephra 71.85 0.78 12.12 3.41 0.04 0.71 2.46 3.13 2.32 96.82 1794 Hekla 4 Tephra 71.80 0.85 12.49 4.11 0.12 0.87 2.86 3.44 2.17 98.71 1794 Hekla 4 Tephra 71.56 0.74 12.17 3.48 0.12 0.75 2.31 2.89 2.22 96.24 1794 Hekla 4 Tephra 71.54 0.87 12.73 3.94 0.14 0.83 2.95 3.27 2.16 98.43 1794 Hekla 4 Tephra 71.44 0.83 12.18 3.20 0.11 0.68 2.31 3.11 2.41 96.27 1794 Hekla 4 Tephra 71.16 0.86 12.53 4.25 0.09 0.87 2.77 2.96 2.36 97.85 1794 Hekla 4 Tephra 70.37 0.88 12.49 4.41 0.15 0.93 3.15 3.29 2.33 98.00 1794 ------------------------------------------------------------------------ 1794: Bergman, J., Wastegard, S., Hammarlund, D., Wohlifarth, B. and Roberts, S.J. (2004) Holocene tephra horizons at Klocka Bog, west-central Sweden: aspects of reproducibility in subarctic peat deposits. Journal of Quaternary Science 19, 241-249..