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NUMBER 19 3.2 36 40 44 Olivine 32 3.6 40 44 4.8 Olivine Inclusion I* Section 10.1 10.2 Inclusion 6 Section 6.1 6.2 Inclusion 11 I Sect ion 11 32 36 40 44 48 Olivine Pyroxene 36 40 44 4B 52 Pyroxene 5.2 %FeO % FeO _L 32 3.6 40 kU 48 5.2 % FeO Pyroxene 32 36 40 4.4 48 Olivine 3.2 36 4.0 4.4 4.8 52 Olivine fl 32 3A 4.0 4.4 4.8 Olivine L 32 3.6 4.0 UU 4.8 Olivine Inclusion 5 Section 51 52 Inclusion 8 Section 8.1 8.2 Inclusion 12 Section 12.1 Inclusion 12 Section 12.2 3.6 40 44 48 5.2 Pyroxene % FeO 36 4.0 4.4 4.8 5.2 % FeO Pyroxene 32 3.6 40 4.4 4.8 52 Pyroxene 3.6 40 4.4 4.8 5.2 Pyroxene 113 % FeO % FeO
114 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES TABLE 3.—FeO content of olivine grains in two thin sections as measured on two different days by electron microprobe Grain No. 18 23 25 89 95 80 Mean SECTION 1 Day 1 Day 2 4.48 4.39 4.07 4.10 4.24 4.30 4.04 4.00 4.31 4.30 4.39 4.39 4.26 4.25 Grain No. 34 36 37 40 41 45 56 62 59 71 Mean SECTION 10 Day 1 Day 2 3.39 3.31 3.60 3.77 3.79 3.49 3.61 3.57 3.72 3.58 3.86 3.73 3.57 3.36 3.40 3.38 2.98 2.99 3.83 3.73 3.56 3.49 Chemical Composition Samples of three silicate inclusions, weighing 3.5 (no. 1), 6.7 (no. 2), and 9 (no. 3) grams, respectively, were taken for chemical analysis. Number 1 was a surface inclusion, and the location of the other two is shown in Figure 3. These samples contained varying amounts of metal as grains dispersed throughout the silicate matrix and veinlets or protrusions extending from the main mass of meteorite into the silicates. Each sample was ground in a tungsten carbide mill and passed through a 100mesh sieve to separate coarse metallic particles from finely ground silicates. Since for this study analyses of the silicates are of prime interest, only the fraction less than 100 mesh was used for analysis. The bulk chemical analysis was performed in a manner similar to that described earlier (Jarosewich, 1966). The results are shown in Table TABLE 4.—Average FeO content of olivine and FeO and CaO content (weight percent) of orthopyroxene of all thin sections studied Inclusion: Section" 1 " 2 2 2: 2 : 1 : 3 : 1 4 : 10.1 10.2 5 : 6 : 8 : 11 : 3.1 3.2 4 9.1 9.2 7 2 5.1 5.2 6.1 6.2 8.1 8.2 11 12. 1*12.1 12. 2*12.2 22 24 47 21 23 14 40 25 17 26 26 31 11 38 24 39 16 32 30 Olivine FeO A 3.88 ± 0.10 3.84 ± 0.19 3.75 ± 0.26 3.87 ± 0.21 3.88 ± 0.19 3.98 ± 0.15 4.06 ± 0.25 4.16 ± 0.14 3.54 ± 0.19 3.60 ± 0.17 4.46 ± 0.19 4.62 + 0.17 3.57 ± 0.25 3.56 ± 0.28 3.99 + 0.15 4.00 ± 0.26 3.63 ± 0.17 4.03 ± 0.25 3.66 ± 0.26 n 29 51 96 26 25 32 29 40 34 37 14 27 35 57 39 26 27 40 33 FeO 4.34 4.29 4.51 4.42 4.51 4.24 4.00 Or thopyroxene A t 0.25 t 0.36 t 0.31 t 0.19 t 0.30 t 0.35 t 0.36 4.54 : t 0.42 4.24 dt 0.33 4.26 db 0.40 3.98 it 0.30 4.11 dt 0.16 4.60 d 0.23 4.70 = t 0.32 4.32 i^ 0.26 4.16 i 0.29 3.85 i 0.23 4.40 i 0.39 4.28 d 0.26 CaO 0.76 ± 0.07 0.77 ± 0.09 0.85 - A 0.80 ± 0.06 0.82 ± 0.09 0.74 ± 0.10 0.78 ± 0.11 0.90 ± 0.15 0.76 ± 0.14 0.82 ± 0.15 0.69 ± 0.09 0.72 ± 0.08 0.86 ± 0.10 0.94 ± 0.17 0.79 ± 0.07 0.75 ± 0.16 0.73 ± 0.07 0.84 ± 0.13 0.78 ± 0.09 The suffix .1 or .2 following a thin section number means that two different areas in the same section were probed. n = number of grains analyzed A = values giving the standard deviation calculated from the distribution of the £ measurements, not from counting statistics. Fa = fayalite Fe~SiO,, mole percent Fs = ferrosilite FeSiO,, mole percent *Inclusions 12.1 and 12.2 are two different pieces on section 12. Fa 3.8 3.7 3.8 4.0 4.0 4.1 3.5 4.5 3.5 4.0 3.6 4.0 3.6 Fs 6.0 6.3 6.2 5.9 5.6 6.4 5.9 5.7 6.6 5.9 5.4 6.2 6.0 Fa/Fs 0.63 0.58 0.61 0.68 0.71 0.64 0.59 0.79 0.53 0.68 0.67 0.64 0.60
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SMITHSONIAN CONTRIBUTIONS TO THE EA
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Contents MINERALOGY COMPOSITION OF
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Constituent SiO TiO Al 0 fl 2 3 Cr
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PER CENT CBLCIUM FIGURE 3.—The ca
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Constituent TiO,, 2 2 3 FeO* MnO Mg
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20 Cfl 40 .60 SMITHSONIAN CONTRIBUT
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35'50' I L 6.. 3.. 2.. r FOKT DEFIA
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12 SMITHSONIAN CONTRIBUTIONS TO THE
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14 20 SMITHSONIAN CONTRIBUTIONS TO
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16 Constituent Si0 2 TiO2 A12O3 Cr
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18 20 40 £0 SMITHSONIAN CONTRIBUTI
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20 40 20 SMITHSONIAN CONTRIBUTIONS
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Abyssal Basaltic Glasses as Indicat
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24 Electron-M icroprobe Analysis An
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30 Hill in the NE Atlantic, and fro
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32 cores the arrangement is stratig
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36 ATLANTIC OCEAN LAT. LONG. DEPTH
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