Sample 70185
Ilmenite Basalt 466.6 grams
Section titled “Ilmenite Basalt 466.6 grams”
Figure 1: Photo of top, zap pitted surface of 70185. NASA S73-15874. Cube is 1 cm. Note the smooth, rounded exterior surface due to micrometeorite erosion.
Introduction
Section titled “Introduction”70185 was collected from the regolith near the deep drill site at the Apollo 17 ALSEP station. It is a coarsegrained high-Ti mare basalt (figure 1). It has micrometeorite craters on all sides and has regions where there are numerous interconnecting vugs (figure 2 and 3).
70185 has not been well studied and has not been dated.
Petrography
Section titled “Petrography”70185 is a granular pyroxene-plagioclase rock with little olivine and abundant ilmenite. Brown et al. (1975) give the mineralogic mode (with rather high ilmenite abundance). The average grain size is about 0.8 mm (figure 4). Mineral chemistry has not been reported.
Chemistry
Section titled “Chemistry”The chemical analyses of 70185 are not in agreement, perhaps because only small portions were analyzed and it is coarse-grained. However, it has less Ti than the majority of Apollo 17 basalts (figure 5). The REE pattern is typical of Apollo 17 basalts (figure 7).
Radiogenic age dating
Section titled “Radiogenic age dating”Nyquist et al. (1976) determined the isotopic composition of Sr, but did not report an age. Apollo 17 mare basalts are generally considered 3.72 ± 0.04 b.y. old (see Paces et al. 1991).
Figure 2: Photo of bottom, freshly broken surface of 70185 showing numerous vugs. NASA S73-17312. Sample is about 7 cm across.
Mineralogical Mode for 70185
Section titled “Mineralogical Mode for 70185”Brown et al. 1975 Olivine 0.4 Pyroxene 47.6 Plagioclase 24 Opaques 23.9 Silica 4.1 Mesotasis -
Cosmogenic isotopes and exposure ages
Section titled “Cosmogenic isotopes and exposure ages”Drozd et al. (1977) found that 70185 had a 81Kr = 113 m.y. exposure age.
O’Kelley et al. (1974) determined the cosmic-rayinduced activity of 22Na = 50 dpm/kg., 26Al = 70 dpm/ kg., 46Sc = 47 dpm/kg., 54Mn = 95 dpm/kg and 56Co = 105 dpm/kg.
Processing
Section titled “Processing”There are 4 thin section of 70185.
Figure 3: 70185 has large vugs that are lined with fresh crystals. S73-17805. Scale about 1 cm across.
Lunar Sample Compendium C Meyer 2011
Lunar Sample Compendium C Meyer 2011
Table 1. Chemical composition of 70185.
| reference weight SiO2 % TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O P2O5 S % sum | 9.6 10.2 18.9 0.237 8.1 11.1 0.433 0.093 | 75 (a) (a) (a) (a) (a) (a) (a) (a) (a) | Eldridge | Rhodes Nyquis 40.18 11.52 9.04 17.64 0.26 8.11 11.95 0.39 0.04 0.02 0.17 | ||
|---|---|---|---|---|---|---|
| Sc ppm V Cr Co Ni Cu Zn Ga Ge ppb As | 84 72 2400 15.9 | (a) (a) (a) (a) | 84 2737 19.7 | (a) (c) (a) | ||
| Se Rb Sr Y Zr Nb Mo Ru Rh Pd ppb Ag ppb Cd ppb In ppb Sn ppb Sb ppb Te ppb Cs ppm | 0.49 173 | (d) (d) | ||||
| Ba La Ce Pr | 11.1 | (a) | 66.3 5.24 18.5 | (d) (d) (d) | ||
| Nd Sm Eu Gd Tb | 15.4 2.74 | (a) (a) | 21.1 8.83 1.87 14 | (d) (d) (d) (d) | ||
| Dy Ho | 28 | (a) | 16 | (d) | ||
| Er Tm | 9.52 | (d) | ||||
| Yb Lu Hf Ta W ppb Re ppb Os ppb Ir ppb Pt ppb Au ppb | 14.7 1.9 | (a) (a) | 8.67 1.21 8.2 | (d) (a) (a) | ||
| Th ppm U ppm technique: | (a) INA | A, (b, | 0.38 0.11 ) radiatior | (b) (b) 1 co | unt. (c ) | XRF, (d) IDMS |
Figure 5: Composition of 70185 compared with that of other Apollo basalts.
Figure 6: Trace element diagram for Apollo 17.
Figure 7: Normalized rare-earth-element diagram for 07185 and type A and B basalts.
References 70185
Section titled “References 70185”Brown G.M., Peckett A., Emeleus C.H., Phillips R. and Pinsent R.H. (1975a) Petrology and mineralogy of Apollo 17 mare basalts. Proc. 6th Lunar Sci. Conf. 1-13.
Butler P. (1973) Lunar Sample Information Catalog Apollo 17. Lunar Receiving Laboratory. MSC 03211 Curator’s Catalog. pp. 447.
Drozd R.J., Hohenberg C.M., Morgan C.J., Podosek F.A. and Wroge M.L. (1977) Cosmic-ray exposure history at Taurus-Littrow. Proc. 8th Lunar Sci. Conf. 3027-3043.
Eldridge J.S., O’Kelley G.D. and Northcutt K.J. (1974a) Primordial radioelement concentrations in rocks and soils from Taurus-Littrow. Proc. 5th Lunar Sci. Conf. 1025-1033.
Lofgren G.E. and Lofgren E.M. (1981) Catalog of Lunar Mare Basalts greater than 40 grams. LPI Cont. 438. Lunar Planetary Institute, Houston
LSPET (1973) Apollo 17 lunar samples: Chemical and petrographic description. Science 182, 659-672.
LSPET (1973) Preliminary Examination of lunar samples. Apollo 17 Preliminary Science Rpt. NASA SP-330. 7-1 – 7-46.
Muehlberger W.R. and many others (1973) Preliminary Geological Investigation of the Apollo 17 Landing Site*. In* Apollo 17 Preliminary Science Report. NASA SP-330.
Neal C.R. and Taylor L.A. (1993) Catalog of Apollo 17 rocks. Vol. 2 Basalts
Nyquist L.E., Bansal B.M. and Wiesmann H. (1976a) Sr isotopic constraints on the petrogenesis of Apollo 17 mare basalts. Proc. 7th Lunar Sci. Conf. 1507-1528.
O’Kelley G.D., Eldridge J.S. and Northcutt K.J. (1974a) Cosmogenic radionuclides in samples from Taurus-Littrow: Effects of the solar flare of August 1972. Proc. 5th Lunar Sci. Conf. 2139-2147.
Rhodes J.M., Hubbard N.J., Wiesmann H., Rodgers K.V., Brannon J.C. and Bansal B.M. (1976a) Chemistry, classification, and petrogenesis of Apollo 17 mare basalts. Proc. 7th Lunar Sci. Conf. 1467-1489.
Warner R.D., Keil K., Murali A.V. and Schmitt R.A. (1975a) Petrogenetic relationships among Apollo-17 basalts. In Papers presented to the Conference on Origins of Mare Basalts and their Implications for Lunar Evolution (Lunar Science Institute, Houston), 179-183.
Wolfe E.W., Bailey N.G., Lucchitta B.K., Muehlberger W.R., Scott D.H., Sutton R.L and Wilshire H.G. (1981) The geologic investigation of the Taurus-Littrow Valley: Apollo 17 Landing Site. US Geol. Survey Prof. Paper, 1080, pp. 280.