Table 11. Major oxide composition of volcanic ash layers. Notes: Shipboard XRF data in weight percent. Shipboard XRF data are uncorrected for carbonate. Total iron reported as "*Fe2O3. LOI = loss on ignition, BDL = below detection limit." "Core, section, interval (cm)" SiO2 TiO2 Al2O3 Fe2O3 MnO MgO CaO Na2O K2O P2O5 Total S LOI CaCO3 Uncorrected values (ppm): 165-999A- "17H-4, 112-114" 55.1 0.94 23.8 9.8 0.04 2.8 2.28 2.4 1.16 0.11 98.43 2.68 11.25 2.8 "20H-2, 142-144" 57.5 0.78 22.5 8.93 0.04 3.19 2.31 2.84 1.01 0.16 99.26 1.93 8.69 1.02 "28X-5, 15-18" 60.2 0.82 20 6.76 0.04 3.7 3.98 2.72 1.1 0.16 99.48 0.63 9.18 4.68 "32X-1, 107-109" 58.7 0.66 19.1 9.65 0.03 3.25 3.43 2.59 1 0.09 98.5 2.94 9.13 3.92 "34X-3, 51-54" 58.5 0.78 14.9 7.48 0.16 1.76 8.93 2.92 2.8 0.32 98.55 0.75 8.27 9.33 "35X-2, 144-149" 70.3 0.3 12.4 2.6 0.09 0.54 6.76 3.08 4.85 0.04 100.96 0.27 10.65 10.22 "37X-6, 98-100" 65.6 0.52 13.6 4.09 0.11 0.82 7.25 3.17 3.84 0.12 99.12 0.44 9.64 10.25 "38X-3, 3-6" 66.2 0.51 14.3 3.01 0.11 0.76 6.92 3.29 4.43 0.13 99.66 0.06 9.59 7.89 "39X-2, 8-11" 73.5 0.19 12.9 1.89 0.07 0.39 2.51 3.42 5.45 0.05 100.37 0.33 6.32 2.61 "41X-6, 98-101" 62.6 0.55 13.1 4.31 0.14 0.77 12.12 3.01 2.83 0.17 99.6 0.12 12.57 14.66 "42X-1, 68-70" 68.7 0.55 13.3 3.14 0.15 0.74 6.7 3.65 3.84 0.11 100.88 0.06 10.01 8.06 "43X-4, 77-80" 68.9 0.29 12.9 2.85 0.09 0.47 7.27 3.53 4.48 0.07 100.85 0.08 9.76 9.72 "44X-2, 135-138" 67.3 0.56 13.6 3.67 0.15 0.79 6.54 3.35 3.56 0.17 99.69 0 9.27 6.58 "45X-5, 123-125" 70 0.5 14.2 3.5 0.09 0.77 2.71 3.47 4.25 0.15 99.64 0.24 6.85 1.24 "46X-2, 11-13" 58.3 0.57 12.7 4.39 0.15 0.75 18.3 2.73 2.76 0.27 100.92 0 15.88 23.32 "48X-1, 14-16" 70.8 0.11 12.2 3.73 0.07 0.27 2.15 3.32 5.3 0.01 97.96 1.58 7.05 3.17 "49X-1, 133-136" 70.6 0.5 13.8 2.99 0.12 0.63 3.24 3.78 4.27 0.12 100.05 0.05 7.05 2.81 "50X-1, 74-77" 73.1 0.09 12.2 2.11 0.05 0.29 3.11 3.55 5.33 0 99.83 0.21 7.32 4.58 "58X-5, 57-60" 71.8 0.34 11.8 2.1 0.06 0.37 7.08 3.07 3.78 0.05 100.45 0 8.87 9.5 "60X-1, 86-88" 63.6 0.99 14.6 6.17 0.14 1.65 7.81 3.22 2.01 0.27 100.46 0.08 9.25 6.24 165-999B- "6R-1, 28-31" 59.3 0.62 17.4 6.86 0.02 3.52 8.32 2.84 0.94 0.06 99.88 0.17 12.96 10 "7R-5, 59-62" 61.7 0.68 16.5 7.21 0.03 3.83 2.47 2.91 1.21 0.07 96.61 0.55 10.23 1.19 "8R-4, 86-89" 62.8 0.34 15.1 5.38 0.04 2.97 8.35 2.85 1.98 0.04 99.85 0.16 12.12 10.75 "9R-2, 98-102" 61.4 1.46 16.7 7.31 0.02 3.16 3.88 3.14 1.79 0.21 99.077 0.215 8.21 2.97 "11R-2, 76-79" 63.6 0.54 17.1 6.33 0.02 3.76 3.87 2.93 1.4 0.08 99.63 0.18 11.35 3.7 "16R-6, 122-125" 56.1 0.72 15.1 5.64 0.03 3.07 13.71 2.22 1.18 0.05 97.81 0.341 15.87 18.47 "24R-3, 103-107" 61.3 1.11 16.4 9.73 0.04 3.38 4.06 2.81 1.34 0.17 100.337 0.16 5.69 1.26 "25R-3, 36-39" 69.1 0.81 13.6 3.43 0.04 1.18 6.01 3.75 2.45 0.1 100.47 0.17 12.2 6.07 "26R-4, 61-63" 65.9 0.79 16.3 6.63 0.03 3.09 3.06 3.24 1.52 0.24 100.798 0.311 8.66 1.01 "27R-3, 26-29" 68.3 0.62 14.2 4.59 0.03 1.89 4.22 3.35 2.05 0.09 99.33 0.174 9.76 13.58 "28R-5, 93-96" 66.6 0.45 15.8 4.41 0.03 2.32 4.26 3.85 2.04 0.06 99.82 0.16 9.17 3.56 "30R-2, 135-138" 68.6 0.54 16.2 4.44 0.03 2.77 2.61 3.37 1.89 0.1 100.546 0.04 10.3 1.02 "31R-5, 6-9" 67 0.66 16.6 6.09 0.04 3.88 2 2.88 1.35 0.11 100.606 0.2 8.4 0.82 "36R-4, 19-21" 67.3 0.52 15.7 4.69 0.02 3.21 3.65 3.05 1.61 0.16 99.908 0.05 10.5 2.72 "37R-3, 9-11" 68.5 0.44 14.9 5.41 0.02 3.13 2.07 3.29 1.84 0.04 99.635 0.11 9.8 0.654 "38R-2, 135-137" 67.3 0.8 15.2 5.31 0.02 4.51 1.61 2.78 1.43 0.1 99.06 0.05 0.93 Values corrected for carbonate content and loss on ignition: 165-999A- "17H-4, 112-114" 56.83 0.97 24.55 10.11 0.04 2.89 0.73 2.48 1.2 0.11 99.9 "20H-2, 142-144" 58.26 0.79 22.8 9.05 0.04 3.23 1.76 2.88 1.02 0.16 99.98 "28X-5, 15-18" 62.09 0.85 20.63 6.97 0.04 3.82 1.4 2.81 1.13 0.17 99.9 "32X-1, 107-109" 60.87 0.68 19.81 10.01 0.03 3.37 1.28 2.69 1.04 0.09 99.86 "34X-3, 51-54" 62.41 0.83 15.89 7.98 0.17 1.88 3.95 3.11 2.99 0.34 99.55 "35X-2, 144-149" 73.65 0.31 12.99 2.72 0.09 0.57 1.08 3.23 5.08 0.04 99.77 "37X-6, 98-100" 69.94 0.55 14.5 4.36 0.12 0.87 1.61 3.38 4.09 0.13 99.56 "38X-3, 3-6" 69.35 0.53 14.98 3.15 0.12 0.8 2.62 3.45 4.64 0.14 99.77 "39X-2, 8-11" 74.3 0.19 13.04 1.91 0.07 0.39 1.06 3.46 5.51 0.05 99.99 "41X-6, 98-101" 67.99 0.6 14.23 4.68 0.15 0.84 4.24 3.27 3.07 0.18 99.26 "42X-1, 68-70" 71.2 0.57 13.78 3.25 0.16 0.77 2.27 3.78 3.98 0.11 99.87 "43X-4, 77-80" 72.07 0.3 13.49 2.98 0.09 0.49 1.91 3.69 4.69 0.07 99.79 "44X-2, 135-138" 69.99 0.58 14.14 3.82 0.16 0.82 2.97 3.48 3.7 0.18 99.84 "45X-5, 123-125" 70.74 0.51 14.35 3.54 0.09 0.78 2.04 3.51 4.29 0.15 99.99 "46X-2, 11-13" 65.38 0.64 14.24 4.92 0.17 0.84 5.87 3.06 3.1 0.3 98.52 "48X-1, 14-16" 73.5 0.11 12.67 3.87 0.07 0.28 0.39 3.45 5.5 0.01 99.85 "49X-1, 133-136" 71.68 0.51 14.01 3.04 0.12 0.64 1.69 3.84 4.34 0.12 99.98 "50X-1, 74-77" 75.1 0.09 12.53 2.17 0.05 0.3 0.56 3.65 5.48 0 99.93 "58X-5, 57-60" 75.3 0.36 12.37 2.2 0.06 0.39 1.84 3.22 3.96 0.05 99.76 "60X-1, 86-88" 65.53 1.02 15.04 6.36 0.14 1.7 4.45 3.32 2.07 0.28 99.91 165-999B- "6R-1, 28-31" 62.69 0.66 18.4 7.25 0.02 3.72 2.87 3 0.99 0.06 99.67 "7R-5, 59-62" 64.2 0.71 17.17 7.5 0.03 3.99 1.88 3.03 1.26 0.07 99.84 "8R-4, 86-89" 66.68 0.36 16.03 5.71 0.04 3.15 2.47 3.03 2.1 0.04 99.62 "9R-2, 98-102" 62.99 1.5 17.13 7.5 0.02 3.24 2.27 3.22 1.84 0.22 99.93 "11R-2, 76-79" 65.15 0.55 17.52 6.48 0.02 3.85 1.84 3 1.43 0.08 99.94 "16R-6, 122-125" 63.13 0.81 16.99 6.35 0.03 3.45 3.78 2.5 1.33 0.05 98.43 "24R-3, 103-107" 61.53 1.11 16.46 9.77 0.04 3.39 3.37 2.82 1.34 0.17 100 "25R-3, 36-39" 71.13 0.83 14 3.53 0.04 1.21 2.69 3.86 2.52 0.1 99.91 "26R-4, 61-63" 65.75 0.79 16.26 6.61 0.03 3.08 2.49 3.23 1.52 0.24 100 "28R-5, 93-96" 68.05 0.46 16.14 4.51 0.03 2.37 2.31 3.93 2.08 0.06 99.95 "30R-2, 135-138" 68.62 0.54 16.2 4.44 0.03 2.77 2.04 3.37 1.89 0.1 100 "31R-5, 6-9" 66.9 0.66 16.58 6.08 0.04 3.87 1.54 2.88 1.35 0.11 100 "36R-4, 19-21" 68.39 0.53 15.95 4.77 0.02 3.26 2.16 3.1 1.64 0.16 99.97 "37R-3, 9-11" 69 0.44 15.01 5.45 0.02 3.15 1.72 3.31 1.85 0.04 99.99 "38R-2, 135-137" 67.93 0.81 15.34 5.36 0.02 4.55 1.63 2.81 1.44 0.1 99.99