Sample 77545
77545 Poikilitic Impact Melt Breccia 29.5 grams
Section titled “77545 Poikilitic Impact Melt Breccia 29.5 grams”
Figure 1: Photo of 77545 showing large vesicles. S73-31348. Sample is 3 cm. across.
Figure 2: Map of station 7, Apollo 17.
Introduction
Section titled “Introduction”Sample 77545 was collected as a rake sample from the soil at station 7 (figure 2). It is a vesicular impact melt breccia similar in texture and composition to 77135, collected from the large boulder nearby. This sample of impact melt has large vesicles (figure 1).
Petrography
Section titled “Petrography”The texture of 77545 is poikiloblastic with interlocking irregular pigeonite oikocrysts enclosing laths and tablets of plagioclase and minor olivine (figure 3). Ilmenite is also poikilitic. Mineral clasts are abundant (mostly plagioclase), but lithic clasts are rare. Warner et al. (1977) give the mineral mode of the matrix of 77545 as 53.2% plagioclase, 44% mafic and 1.6% ilmenite.
The composition of pyroxene and olivine is given in figure 4. Plagioclase is An Warner et al. (1978) 82-98.
Figure 3a: Photomicrographs of thin section 77545,6 by C Meyer @50x.
Figure 3b: Photomicrographs of thin section 77545,7 by C Meyer @50x.
also report the composition of ilmenite, chromite and armalcolite.
Significant clast
Section titled “Significant clast”A large angular clast of olivine was studied by Warner et al. (1977). The clast has a granoblastic texture, with mm size olivine grains intersecting at near 120 deg triple junctions. The olivine in the clast is Fo89 and there are chromite grains located along the olivine grain boundaries.
Chemistry
Section titled “Chemistry”The analysis by Wasson et al. (1977) is similar to that for 77135 (figure 5).
Processing
Section titled “Processing”77545 has been chipped, not sawn. There are 6 thin sections.
Figure 4: Pyroxene and olivine composition of matrix of 77545 (Warner et al. 1977).
Figure5: Normalized rare-earth-element diagram for 77545.
Mineral Mode ( Warner et al. 1977)
Section titled “Mineral Mode ( Warner et al. 1977)”| Vol. % | |
|---|---|
| Matrix | 74.6 |
| Mineral clasts | 9.4 |
| Lithic clasts | 16 |
Mineral clasts
Section titled “Mineral clasts”Plagioclase 6.7 Olivine/Pyroxene 2.7 Opaque Metal/troilite
Other
Lithic Clasts
Section titled “Lithic Clasts”| 14.9 |
|---|
| 0.9 |
| 0.2 |
Percent of matrix
Section titled “Percent of matrix”Plagioclase 53.2 Olivine/pyroxene 44 Opaque 1.6 Metal/troilite 0.2 Other 1
Lunar Sample Compendium C Meyer 2011
Table 1. Chemical composition of 77545.
| reference Laul75 weight SiO2 % TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O P2O5 S % sum | Warner77 | Wasson77 | ||||
|---|---|---|---|---|---|---|
| 1.2 10.9 10.3 0.11 10 6.6 0.47 0.14 | (a) 1.2 (a) 10.9 (a) 10.3 (a) 0.11 (a) 10 (a) 6.6 (a) 0.47 (a) 0.14 | 1.5 18.7 8.9 12.93 11 0.71 0.24 | 1.8 19.8 9.7 0.12 13.8 11.9 0.7 0.29 | (a) (a) (a) (a) (a) (a) (a) (a) | ||
| Sc ppm V | 11 70 | (a) (a) | 17 | 17.6 49 | (a) (a) | |
| Cr Co Ni | 67 600 | (a) (a) | 3558 | 1400 13.5 60 | 1440 17.5 60 | (a) (a) (a) |
| Cu Zn Ga Ge ppb As Se Rb Sr | 1.9 5.5 50 | 5.3 120 | ||||
| Y Zr Nb Mo Ru Rh Pd ppb | 240 | (a) | 560 | 590 | (a) | |
| Ag ppb Cd ppb In ppb Sn ppb Sb ppb Te ppb Cs ppm | 2.8 0.35 | 10 0.32 | ||||
| Ba La Ce | 220 21.5 55 | (a) (a) (a) | 340 32.2 82 | 380 35.7 85 | (a) (a) (a) | |
| Pr Nd Sm Eu | 35 9.8 1.3 | (a) (a) (a) | 51 15.4 2 | 59 15.3 2.15 | (a) (a) (a) | |
| Gd Tb Dy Ho Er | 2 12 | (a) (a) | 3.1 23 | 3.2 19 | (a) (a) | |
| Tm Yb Lu Hf Ta W ppb Re ppb | 6.3 0.94 8.2 1 | (a) (a) (a) (a) | 11 1.52 11.8 1.4 | 11.6 1.62 12.1 1.5 | (a) (a) (a) (a) | |
| Os ppb Ir ppb Pt ppb | 7 | (a) | 1 | (a) | ||
| Au ppb Th ppm U ppm technique (a) INAA | 2 3.2 0.9 | (a) (a) (a) | 0.8 5.4 1.4 | 1.5 5.3 1.4 | (a) (a) (a) |
References for 77545
Section titled “References for 77545”Butler P. (1973) Lunar Sample Information Catalog Apollo 17. Lunar Receiving Laboratory. MSC 03211 Curator’s Catalog. pp. 447.
Laul J.C. and Schmitt R.A. (1975c) Chemical composition of Apollo 17 samples: Boulder breccias (2), rake breccias (8), and others (abs). Lunar Sci. VI, 489-491. 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.
Meyer C. (1994) Catalog of Apollo 17 rocks: Volume 4. Curator’s Office JSC 26088 pp. 644 76 78
Meyer C. (2010) Lunar Sample Compendium (abs#1016). The 41st Lunar Planet. Sci. Conf. @ The Woodlands
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. Meyer C. (1994) Catalog of Apollo 17 rocks: Volume 4. Curator’s Office JSC 26088 pp. 644
Warner R.D., Taylor G.J. and Keil K. (1977b) Petrology of crystalline matrix breccias from Apollo 17 rake samples. Proc. 8th Lunar Sci. Conf. 1987-2006.
Warner R.D., Keil K., Nehru C.E. and Taylor G.J. (1978) Catalogue of Apollo 17 rake samples from Stations la, 2, 7, and 8. Spec. Publ. #18, UNM Institute of Meteoritics, Albuquerque. 88 pp.
Wasson J.T., Warren P.H., Kallemeyn G.W., McEwing C.E., Mitdefehldt D.W. and Boynton W.V. (1977) SCCRV, a major component of highlands rocks. Proc. 8th Lunar Sci. Conf. 2237-2252.
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.