Sample 77517
Unique Fragmental Breccia 45.6 grams
Section titled “Unique Fragmental Breccia 45.6 grams”
Figure 1: Photo of 77517. S73-19408. Each piece is about 2 cm.
Introduction
Section titled “Introduction”77517 is a fragmental breccia with aphanitic matrix. It is light-colored and appears unique. Sample 77517 may be exotic to the Apollo 17 site because it contains mineral fragments of pink aluminous spinel, aluminous enstatite and foresterite – not normally components at Apollo 17.
This rock deserves to be taken apart clast by clast – but how do you do that?
Petrography
Section titled “Petrography”77517 has abundant mineral and lithic clasts in a highly porous, poorly sintered matrix (figure 3). The mineral fragments are loosely held in the fragmental matrix. Lithic clast include anorthosite, norite, troctolite and spinel cataclasite.
Mineral compositions are variable (figure 4). Pink spinel grains up to 400 microns are reported.
Significant clasts
Section titled “Significant clasts”Spinel Cataclasite: Warner et al. (1978) and Baker and Herzberg (1980) report on a clast assemblage – aluminous enstatite + foresterite + plagioclase + aluminous spinel).
Chemistry
Section titled “Chemistry”None
Processing
Section titled “Processing”77517 was returned in three pieces in a bag with other rocks and additional fragments (77510 - 4). There are 7 thin sections.
References for 77517
Section titled “References for 77517”Baker M.B. and Herzberg C.T. (1980a) Spinel cataclasites in 15445 and 72435: Petrology and criteria for equilibrium. Proc. 11th Lunar Planet. Sci. Conf. 535-553.
Butler P. (1973) Lunar Sample Information Catalog Apollo 17. Lunar Receiving Laboratory. MSC 03211 Curator’s Catalog. pp. 447.
Herzberg C.T. (1978) The bearing of spinel cataclasites on the crust-mantle structure of the Moon. Proc. 9th Lunar Planet. Sci. Conf. 319-336.
LSPET (1973) Apollo 17 lunar samples: Chemical and petrographic description. Science 182, 659-672.
Figure 2: Map of station 7, Apollo 17.
Figure 3: Photomicrograph of thin section of 77517.
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
Meyer C. (2010) Lunar Sample Compendium (abs#1016). The 41st Lunar Planet. Sci. Conf. @ The Woodlands
Figure 4: Composition of olivine and pyroxene in 77517 (Warner et al. 1977).
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.
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.
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.
