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Table 3 Major element concentrations (weight %) for the deep sea sediments of the southwestern Gulf of Mexico

From: Textural and geochemical characteristics of late Pleistocene to Holocene fine-grained deep-sea sediment cores (GM6 and GM7), recovered from southwestern Gulf of Mexico

Core No. GM6
 Section (cm) 0–1 31–32 46–47 61–62 76–77 91–92 121–122 136–137 151–152 166–167 180–181
  vol. free SiO2 56.2 55.9 54.6 54.2 54.7 54.8 55.1 53.9 53.7 54.9 54.5
  SiO2 45.7 45.3 44.1 44.1 45.5 45.2 44.8 44.1 43.8 46.0 44.7
  TiO2 0.617 0.645 0.612 0.689 0.626 0.651 0.714 0.624 0.653 0.625 0.656
  Al2O3 14.2 13.9 14.0 15.6 14.8 14.4 14.9 13.9 14.7 15.0 14.3
  Fe2O3* 5.80 5.74 5.83 5.62 5.57 5.37 5.78 5.24 5.86 5.76 5.64
  MnO 0.048 0.054 0.127 0.041 0.050 0.053 0.081 0.095 0.075 0.086 0.680
  MgO 2.41 2.44 2.42 2.33 2.42 2.34 2.37 2.44 2.53 2.55 2.39
  CaO 7.68 7.98 8.92 8.36 9.48 10.2 8.46 11.2 9.54 8.94 9.33
  Na2O 3.49 3.54 3.42 3.27 2.61 2.36 2.65 2.25 2.68 2.60 2.57
  K2O 1.24 1.36 1.23 1.25 1.86 1.67 1.46 1.69 1.57 2.06 1.54
  P2O5 0.119 0.125 0.121 0.136 0.222 0.231 0.124 0.239 0.204 0.212 0.216
  LOI 17.1 17.6 16.8 17.9 16.8 16.7 17.8 17.4 17.6 16.5 17.2
  Sum 98.3 98.5 97.5 99.3 99.9 99.1 99.0 99.1 99.1 100.3 99.1
  CIA 67 65 63 69 64 62 68 58 64 65 64
  CIW 72 70 67 74 69 67 73 63 69 72 69
  PIA 70 67 65 72 66 64 71 59 66 68 66
  ICV 1.50 1.57 1.61 1.38 1.53 1.57 1.45 1.70 1.56 1.51 1.60
  SiO2/Al2O3 3.23 3.27 3.16 2.82 3.07 3.14 3.01 3.18 2.99 3.08 3.13
  K2O/Na2O 0.354 0.383 0.359 0.382 0.711 0.708 0.549 0.748 0.587 0.795 0.598
  Al2O3/Na2O 4.05 3.91 4.09 4.79 5.67 6.09 5.62 6.15 5.47 5.76 5.54
  K2O/Al2O3 0.087 0.098 0.088 0.080 0.125 0.116 0.098 0.122 0.107 0.138 0.108
 Section (cm) 196–197 210–211 222–223 226–227 241–242 256–257 300–301 316–317 330–331 Mean ± 1 s (n = 20)
  vol. free SiO2 55.5 55.5 54.9 53.7 55.0 53.9 54.5 55.1 53.6 54.7 ± 0.74
  SiO2 45.5 44.8 44.9 44.9 45.2 44.0 44.7 45.8 44.4 44.9 ± 0.67
  TiO2 0.635 0.638 0.623 0.625 0.647 0.613 0.631 0.612 0.745 0.64 ± 0.04
  Al2O3 14.1 14.3 13.7 14.9 15.5 13.5 15.7 14.5 15.4 14.6 ± 0.66
  Fe2O3* 5.85 5.37 5.46 5.60 5.36 5.12 5.42 5.85 5.73 5.6 ± 0.23
  MnO 0.785 0.096 0.076 1.835 0.086 0.139 0.074 0.470 0.650 0.28 ± 0.44
  MgO 2.29 2.44 2.30 2.59 2.44 2.35 2.50 2.45 2.55 2.43 ± 0.09
  CaO 8.25 8.79 10.8 8.39 8.76 11.7 8.86 9.06 8.97 9.18 ± 1.06
  Na2O 2.72 2.25 2.34 2.72 2.34 2.56 2.21 2.55 2.21 2.67 ± 0.43
  K2O 1.79 1.80 1.33 1.81 1.75 1.31 1.68 1.63 1.97 1.60 ± 0.25
  P2O5 0.120 0.229 0.234 0.192 0.236 0.251 0.224 0.201 0.216 0.193 ± 0.05
  LOI 15.6 17.7 17.8 16.3 17.6 18.0 17.5 17.2 17.2 17.2 ± 0.61
  Sum 97.6 98.4 99.5 100.0 99.9 99.6 99.5 100.3 100.0 99.2 ± 0.82
  CIA 65 65 59 67 68 56 69 65 67 65 ± 4
  CIW 71 71 63 73 74 60 75 70 74 70 ± 4
  PIA 69 68 61 71 72 57 73 68 71 67 ± 4
  ICV 1.59 1.50 1.67 1.58 1.38 1.76 1.36 1.56 1.48 1.54 ± 0.10
  SiO2/Al2O3 3.24 3.14 3.27 3.01 2.93 3.25 2.84 3.16 2.87 3.09 ± 0.14
  K2O/Na2O 0.659 0.800 0.568 0.665 0.748 0.512 0.760 0.639 0.888 0.621 ± 0.16
  Al2O3/Na2O 5.18 6.35 5.87 5.50 6.60 5.28 7.12 5.70 6.97 5.58 ± 0.09
  K2O/Al2O3 0.127 0.126 0.097 0.121 0.113 0.097 0.107 0.112 0.137 0.110 ± 0.016
Core No. GM7
 Section (cm) 0–1 31–32 46–47 61–62 76–77 91–92 121–122 136–137 151–152 166–167 180–181
  vol. free SiO2 54.6 55.0 54.0 55.0 54.8 54.1 53.5 54.9 56.5 54.4 56.0
  SiO2 45.7 44.9 43.7 45.8 45.7 43.8 43.6 45.3 47.3 44.3 45.9
  TiO2 0.605 0.670 0.570 0.680 0.604 0.571 0.585 0.621 0.680 0.618 0.740
  Al2O3 15.0 15.9 13.7 15.7 14.4 13.2 13.4 14.0 14.8 14.4 14.7
  Fe2O3* 5.80 5.13 4.96 4.98 5.82 4.95 4.90 5.26 5.12 5.45 5.78
  MnO 0.087 0.081 0.129 0.076 0.164 0.127 0.067 0.091 0.040 1.564 0.120
  MgO 2.46 2.56 2.35 2.68 2.49 2.33 2.24 2.36 2.31 2.53 1.98
  CaO 9.28 8.69 11.6 8.78 9.60 12.0 12.8 10.7 9.15 8.35 8.69
  Na2O 2.54 2.26 2.29 2.89 2.53 2.12 2.34 2.46 2.46 2.52 2.13
  K2O 2.06 1.26 1.47 1.48 1.90 1.63 1.37 1.40 1.58 1.44 1.79
  P2O5 0.208 0.180 0.249 0.190 0.207 0.252 0.160 0.242 0.210 0.201 0.140
  LOI 16.0 18.0 19.0 16.7 17.2 18.5 18.5 16.9 16.2 17.5 17.6
  Sum 99.8 99.6 100.0 99.9 100.7 99.4 100.0 99.5 99.8 98.9 99.5
  CIA 64 71 57 68 63 55 54 60 66 68 67
  CIW 71 76 61 73 68 59 57 64 71 72 73
  PIA 68 74 58 71 65 56 55 62 68 70 70
  ICV 1.52 1.30 1.71 1.38 1.60 1.80 1.80 1.63 1.44 1.56 1.45
  SiO2/Al2O3 3.04 2.83 3.20 2.92 3.17 3.33 3.24 3.23 3.20 3.07 3.13
  K2O/Na2O 0.812 0.558 0.643 0.512 0.752 0.766 0.585 0.570 0.642 0.573 0.840
  Al2O3/Na2O 5.92 7.02 5.98 5.43 5.70 6.20 5.74 5.71 6.01 5.72 6.88
  K2O/Al2O3 0.137 0.079 0.108 0.094 0.132 0.124 0.102 0.100 0.107 0.100 0.122
 Section (cm) 196–197 210–211 222–223 226–227 241–242 256–257 300–301 316–317 330–331 Mean ± 1 s (n = 20)
  vol. free SiO2 55.3 56.0 54.5 55.0 55.0 55.3 55.5 56.9 55.4 55.1 ± 0.83
  SiO2 46.7 47.0 44.3 45.0 44.7 45.3 45.4 47.7 45.2 45.4 ± 1.16
  TiO2 0.625 0.730 0.572 0.593 0.680 0.690 0.690 0.725 0.620 0.643 ± 0.056
  Al2O3 14.9 14.3 13.0 14.7 16.0 13.6 14.4 14.3 15.1 14.5 ± 0.84
  Fe2O3* 5.87 5.91 4.79 5.20 4.23 5.12 4.79 5.84 5.06 5.25 ± 0.46
  MnO 0.114 0.250 0.114 0.081 0.180 0.078 0.260 0.061 0.080 0.188 ± 0.33
  MgO 2.59 1.76 2.39 2.36 2.25 2.41 2.87 2.36 2.49 2.39 ± 0.24
  CaO 8.53 9.46 12.3 8.69 8.36 9.56 8.49 8.26 8.37 9.58 ± 1.45
  Na2O 2.82 2.24 2.14 2.76 2.36 2.65 2.68 2.73 2.49 2.47 ± 0.23
  K2O 2.06 2.06 1.39 2.36 2.24 2.36 2.03 1.74 1.89 1.78 ± 0.35
  P2O5 0.188 0.230 0.262 0.109 0.270 0.117 0.190 0.188 0.170 0.198 ± 0.045
  LOI 16.1 16.0 18.1 15.7 18.0 16.8 17.5 14.9 18.4 17.2 ± 1.11
  Sum 100.5 99.9 99.3 97.6 99.2 98.6 99.2 98.8 99.8 99.5 ± 0.68
  CIA 66 63 54 64 69 59 65 66 68 63 ± 5
  CIW 72 69 58 71 77 66 71 72 74 69 ± 6
  PIA 69 66 55 68 74 61 68 69 72 66 ± 6
  ICV 1.51 1.57 1.82 1.50 1.27 1.68 1.52 1.52 1.39 1.55 ± 0.16
  SiO2/Al2O3 3.13 3.29 3.40 3.06 2.80 3.33 3.15 3.34 2.99 3.14 ± 0.17
  K2O/Na2O 0.729 0.920 0.651 0.857 0.949 0.891 0.757 0.637 0.759 0.72 ± 0.13
  Al2O3/Na2O 5.30 6.37 6.10 5.34 6.77 5.12 5.37 5.23 6.07 5.90 ± 0.55
  K2O/Al2O3 0.138 0.144 0.107 0.160 0.140 0.174 0.141 0.122 0.125 0.123 ± 0.174
  1. Abbreviations: 1 s-One standard deviation, n Total number of samples, LOI Loss of ignition, CIA Chemical index of alteration (Nesbitt and Young 1982), CIW Chemical index of weathering (Harnois 1988), PIA Plagioclase index of alteration (Fedo et al. 1995), ICV Index of compositional variability (Cox et al. 1995), Fe2O3* Total Fe expressed as Fe2O3. Refer to Table 1, for water depth, latitude and longitude