Sample 12008
Olivine Vitrophyre Basalt 58.4 grams
Section titled “Olivine Vitrophyre Basalt 58.4 grams”
Figure 1: Photo of 12008,0 after dusting. NASA photo # S70-47882. Sample is 2 cm across.
Introduction
Section titled “Introduction”12008 is an olivine vitrophyre very similar to 12009 and 12015, but with slightly higher TiO2 content. The age has been determined to be about 3.2 b.y.
Petrography
Section titled “Petrography”Dungan and Brown (1977) describe 12008 as ~15-20% equant subhedral to euhedaral phenocrysts of olivine (0.2 -0.5 mm) heterogeneously distributed in the opaque groundmass as glomerophyric aggregates (Fo72). Small chromite grains with attached metallic
iron grains are found in the groundmass or attached to the rims of the olivine phenocrysts. Olivine includes spherical melt inclusions. A second generation of olivine occurs as chains of skeletal microphenocrysts (Donaldson et al. 1975). The fine-grained opaque matrix is made of microlites of aluminous titanaugite, ilmenite and plagioclase (?).
Figure 2: Photomicrograph of thin section 12008,20 showing olivine phenocrysts in nearly opaque groundmass. NASA # S76-29979. Length about 3 mm.
Mineralogy
Section titled “Mineralogy”Olivine: Olivine in 12008 is mostly Fo72 (Dungan and Brown 1977). Butler (1973) determined the minor element content of olivine.
Pyroxene: Dungan and Brown (1977) reported the composition of dendrites of pyroxene in 12008 (figure 3).
Metal: Brett et al. (1971) determined the Ni content of minute metallic iron grains in 12008 (figure 4).
Mineralogical Mode for 12008
Section titled “Mineralogical Mode for 12008”| Neal et | |
|---|---|
| al. 1994 | |
| Olivine | 38.2 |
| Pyroxene | 20.4 |
| Plagioclase | 2 |
Figure 3: Olivine and pyroxene composition of 12008 (from Dungan and Brown 1977).
Figure 4: Histogram of Ni conentrations of metal grains in 7 lunar samples (lifted from Brett et al. 1971).
| Summary of Age Data for 12008 | ||
|---|---|---|
| Ilmenite | 4.7 | |
Chromite +Usp 0.6 Ar/Ar Rb/Sr Mesostasis 33.9 Stettler et al. 1973 3.18 ± 0.07 b.y “silica” 3.09 ± 0.07
Figure 5: Composition of 12008 compared with other lunar basalts.
Chemistry
Section titled “Chemistry”The chemical composition of 12008 was determined by Rhodes et al. (1977), Jarosowich et al. (1977) (figure 5). Trace elements were determined by Nyquist et al. (1977) and Anders et al. (1971) (figure 6).
Radiogenic age dating
Section titled “Radiogenic age dating”Stettler et al. (1973) determined an age for 12008 by total Argon 39/40 (see table). The high temperature release represented a lower age (see figure in 12051).
Cosmogenic isotopes and exposure ages
Section titled “Cosmogenic isotopes and exposure ages”Stettler et al. (1973) determined an 38Ar exposure age of 50 m.y.
Other Studies
Section titled “Other Studies”Clayton et al. (1971) reported oxygen isotope analysis of olivine and matrix of 12008.
Processing
Section titled “Processing”There ar 10 thin sections.
List of Photo #s of 12008
Section titled “List of Photo #s of 12008”| S69-63190 – 63213 | color mug |
|---|---|
| S70-47876 – 47833 | B & W mug |
| S70-44092 | color |
| S70-49238 – 49243 | TS color |
| S70-46343 | reflected TS ,17 |
| S70-46567 | reflected TS ,19 |
| S70-44557 | reflected TS, 14 |
| S70-44572 | reflected TS, 15 |
| S70-46349 | reflected TS ,20 |
| S76-29979 | TS ,20 |
| S70-47875 – 47878 | processing |
| S94-035798 | processing |
Figure 6: Rare-earth-element data for 12008 normalized by chondritic abundance (from Nyquist et al. 1977).
References for 12008
Section titled “References for 12008”Anders E., Ganapathy R., Keays R.R., Laul J.C., and Morgan J.W. (1971) Volatile and siderophile elements in lunar rocks: Comparsion with terrestrial and meteoritic basalts. Proc. 2nd Lunar Sci. Conf. 1021-1036.
Anders E., Ganapathy R., Krahenbuhl U. and Morgan J.W. (1973) Meteoritic material on the Moon. The Moon 8, 3 24.
Brett R., Butler P., Meyer C., Reid A.M., Takeda H. and Williams R. (1971) Apollo 12 igneous rocks 12004, 12008, 12009 and 12022: A mineralogical and petrological study. Proc. 2nd Lunar Sci. Conf. 301-317.
Butler P. (1972b) Compositional characteristics of olivines from Apollo 12 samples. Geochim. Cosmochim. Acta 36, 773-785.
Clayton R.N., Onuma N. and Mayeda T.K. (1971) Oxygen isotope fractionation in Apollo 12 rocks and soils. Proc. Second Lunar Sci. Conf. 1417-1420.
Donaldson C.H., Drever H.I. and Johnston R. (1977) Supercooling on the lunar surface: a review of analogue information. Phil. Trans. Roy. Soc. London A285, 207-218.
Dungan M.A. and Brown R.W. (1977) The petrology of the Apollo 12 basalt suite. Proc. 8th Lunar Sci. Conf. 1339 1381.
James O.B. and Wright T.L. (1972) Apollo 11 and 12 mare basalts and gabbros: Classification, compositional variations
Table 1. Chemical composition of 12008
| weight | reference Rhodes77 .5 g | Jarosowich77 | Nyquist77 38 mg | Anders71 | Neal2001 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SiO2 % TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O P2O5 S % sum | 42.75 4.45 7.98 21.94 0.3 12.33 8.97 0.25 0.05 0.07 0.08 | (a) | (a) 42.58 (a) 4.82 (a) 8.49 (a) 22.4 (a) 0.28 (a) 11.99 (a) 9.1 (d) 0.24 (a) 0.14 (a) 0.05 | (b) (b) (b) (b) (b) (b) (b) (b) (b) | (b) 0.054 | (c ) | |||||
| Sc ppm | 52.4 | (d) | 56 | (f) | |||||||
| V Cr Co Ni | 4200 51 | (d) (d) | 60 | 164 3908 (e) 63.2 64 | (f) (f) (f) (f) | ||||||
| Cu Zn Ga Ge ppb | 1.04 3.2 | 20.8 (e) 28.5 (e) 3.44 | (f) (f) (f) | ||||||||
| As Se Rb Sr Y Zr Nb Mo Ru | 130 45 117 5.9 | (a) (a) (a) (a) | 0.681 133 | (c ) | 0.139 (c ) 0.62 | (e) | (e) 0.9 144 55 118 6.7 0.22 | (f) (f) (f) (f) (f) (f) | |||
| Rh Pd ppb Ag ppb Cd ppb In ppb Sn ppb Sb ppb | 1.17 1.3 | (e) (e) | |||||||||
| Te ppb Cs ppm | 50 0.028 | (e) | (e) 0.01 | (f) | |||||||
| Ba | 51 | (c ) | 49.6 | (c ) | 59 | (f) | |||||
| La Ce | 16.9 | (d) | 15.4 | (c ) | 5.8 15.7 | (f) (f) | |||||
| Pr Nd Sm Eu Gd | 3.35 1.06 | (d) (d) | 13.9 5.14 1.17 7.39 | (c ) (c ) (c ) (c ) | 2.62 13.6 5.11 1.17 7.23 | (f) (f) (f) (f) (f) | |||||
| Tb Dy | 1.39 | (d) | 8.88 | (c ) | 1.28 8.68 | (f) (f) | |||||
| Ho Er | 5.27 | (c ) | 1.79 5.27 | (f) (f) | |||||||
| Tm Yb Lu Hf Ta W ppb Re ppb | 4.9 0.71 3.8 | (d) (d) (d) | 4.55 0.657 | (c ) (c ) | 0.71 4.68 0.61 3.62 0.34 40 | (f) (f) (f) (f) (f) (f) | |||||
| Os ppb Ir ppb | 0.06 | (e) | |||||||||
| Pt ppb Au ppb Th ppm U ppm | 0.074 | (e) | 0.59 0.15 | (f) (f) | |||||||
| technique: (a) XRF, (b) wet, (c ) IDMS, (d) INAA, (e) RNAA, (f) ICP-MS |
THE CHIPPING OF LUNAR ROCK 12008
Section titled “THE CHIPPING OF LUNAR ROCK 12008”
and possible petrogenetic relations. Geol. Soc. Am. Bull. 83, 2357-2382.
Jarosewich E. and Mason B. (1977) Compositions of lunar basalts 10069, 10071 and 12008. In Lunar Sample Studies. (ed. W. Phinney) NASA SP-418
LSPET (1970) Preliminary examination of lunar samples from Apollo 12. Science 167, 1325-1339.
Neal C.R. (2001) Interior of the moon: The presence of garnet in the primitive deep lunar mantle. J. Geophys. Res. 106, 27865-27885.
Nyquist L.E., Bansal B.M., Wooden J. and Wiesmann H. (1977) Sr-isotopic constraints on the peterogenesis of Apollo 12 mare basalts. Proc. 8th Lunar Sci. Conf. 1383-1415.
Nyquist L.E., Shih C.-Y., Wooden J.L., Bansal B.M. and Wiesmann H. (1979) The Sr and Nd isotopic record of Apollo 12 basalts: Implications for lunar geochemical evolution. Proc. 10th Lunar Planet. Sci. Conf. 77-114.
Rhodes J.M., Blanchard D.P., Dungan M.A., Brannon J.C., and Rodgers K.V. (1977) Chemistry of Apollo 12 mare basalts: Magma types and fractionation processes. Proc. 8th Lunar Sci. Conf. 1305-1338.
Stettler A., Eberhardt Peter, Geiss J., Grogler N. and Maurer P. (1973) Ar39-Ar40 ages and Ar37-Ar38 exposure ages of lunar rocks. Proc. 4th Lunar Sci. Conf. 1865-1888.
