Table T8. Representative plagioclase composition for the major rock types, Hole 735B. (Continued on next four pages.)
Leg, hole:
118-735B- 176-735B-
118-735B-
176-735B-
Core, section: Interval (cm):
87R-6
106-114
87R-7
0-7
87R-7
0-7
87R-7
0-7
79R-6
105-111
79R-6
105-111
83R-6
53-59
85R-7
0-5
91R-5
81-86
91R-3
67-72
91R-3
67-72
91R-5
81-86
144R-1
113-122
141R-1
50-55
87R-6
31-41
205R-4
40-45
Rock type: Troctolite Troctolitic gabbro Olivine gabbro
Major element oxide (wt%):                          
                                 
SiO2 51.71 51.63 51.90 55.67 48.22 49.39 49.06 51.78 49.37 50.00 51.24 52.04 52.68 53.74 53.14 53.78
TiO2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.09 0.03 0.05 0.00 0.04 0.00
Al2O3 30.95 30.46 29.71 27.60 32.88 32.40 32.38 30.86 32.44 31.85 31.02 30.96 29.63 28.85 29.32 28.84
Fe2O3 0.12 0.18 0.22 0.14 0.07 0.07 0.06 0.21 0.07 0.13 0.07 0.00 0.32 0.22 0.24 0.38
CaO 13.85 13.24 12.41 10.06 16.19 15.44 15.31 13.87 15.34 15.00 14.02 13.10 12.83 12.22 11.86 11.92
Na2O 3.72 4.05 4.19 6.08 2.51 2.82 3.26 3.15 2.96 3.11 3.78 4.17 4.59 4.76 4.62 5.34
K2O 0.01 0.05 0.03 0.03 0.00 0.00 0.00 0.12 0.00 0.05 0.01 0.00 0.04 0.06 0.03 0.04
BaO 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.12 0.00 0.15 0.00 0.00 0.08
Total 100.36 99.61 98.52 99.58 99.87 100.12 100.07 99.99 100.19 100.28 100.35 100.29 100.29 99.85 99.25 100.38
Number of cations based on 8 O:                          
Si 2.3409 2.3542 2.3866 2.5165 2.2117 2.2526 2.2429 2.3491 2.2507 2.2771 2.3256 2.3530 2.3883 2.4361 2.4203 2.4310
Ti 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0014 0.0031 0.0011 0.0016 0.0000 0.0014 0.0000
AlIV 1.6513 1.6369 1.6102 1.4704 1.7774 1.7415 1.7446 1.6500 1.7431 1.7095 1.6592 1.6470 1.5833 1.5416 1.5739 1.5365
AlVI 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0030 0.0000 0.0000 0.0000 0.0000
Fe+3 0.0041 0.0062 0.0077 0.0048 0.0024 0.0024 0.0021 0.0072 0.0026 0.0045 0.0024 0.0000 0.0110 0.0075 0.0082 0.0130
Ca 0.6717 0.6468 0.6113 0.4872 0.7955 0.7544 0.7499 0.6741 0.7493 0.7318 0.6817 0.6344 0.6233 0.5933 0.5787 0.5773
Na 0.3265 0.3580 0.3739 0.5328 0.2232 0.2493 0.2889 0.2771 0.2616 0.2746 0.3326 0.3651 0.4036 0.4185 0.4079 0.4678
K 0.0006 0.0029 0.0018 0.0017 0.0000 0.0000 0.0000 0.0069 0.0000 0.0029 0.0006 0.0000 0.0024 0.0035 0.0017 0.0022
Ba 0.0000 0.0000 0.0009 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0018 0.0021 0.0000 0.0026 0.0000 0.0000 0.0014
Total ions 4.9951 5.0049 4.9924 5.0133 5.0102 5.0003 5.0284 4.9644 5.0074 5.0035 5.0073 5.0036 5.0161 5.0005 4.9922 5.0293
An 67.3 64.2 61.9 47.7 78.1 75.2 72.2 70.4 74.1 72.5 67.2 63.5 60.6 58.4 58.6 55.1
Ab 32.7 35.5 37.9 52.1 21.9 24.8 27.8 28.9 25.9 27.2 32.8 36.5 39.2 41.2 41.3 44.7
Or 0.1 0.3 0.2 0.2 0.0 0.0 0.0 0.7 0.0 0.3 0.1 0.0 0.2 0.3 0.2 0.2

Note: An = anorthite, Ab = albite, Or = orthoclase.