Abstract
Boulder 1, Station 2, Apollo 17 is a stratified boulder containing dark clasts and dark-rimmed light clasts set in a light-gray friable matrix. The gray to black clasts (GCBx and BCBx) are multigenerational, competent, high-grade metamorphic, and partially melted breccias. They contain a diverse suite of lithic clasts which are mainly ANT varieties, but include granites, basaltic-textured olivine basalts, troctolitic and spinel troctolitic basalts, and unusual lithologies such as KREEP norite, ilmenite (KREEP) microgabbro, and the Civet Cat norite, which is believed to be a plutonic differentiate. The GCBxs and BCBxs are variable in composition, averaging a moderately KREEPy olivine norite. The matrix consists of mineral fragments derived from the observed lithologies plus variable amounts of a component, unobserved as a clast-type, that approximates a KREEP basalt in composition, as well as mineral fragments of unknown derivation. The high-temperature GCBxs cooled substantially before their incorporation into the friable matrix of Boulder 1.
The light friable matrix (LFBx) is texturally distinct from the competent breccia clasts and, apart from the abundant ANT clasts, contains clasts of a KREEPy basalt that is not observed in the competent breccias. The LFBx lacks such lithologies as the granites and the Civet Cat norite observed in the competent breccias and in detail is a distinct chemical as well as textural entity. We interpret the LFBx matrix as Serenitatis ejecta deposited in the South Massif, and the GCBx clasts as remnants of an ejecta blanket produced by an earlier impact. The source terrain for the Serenitatis impact consisted of the competent breccias, crustal ANT lithologies, and the KREEPy basalts, attesting to substantial lunar activity prior to the impact. The age of the older breccias suggests that the Serenitatis event is younger than 4.01±0.03 b.y.
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References
AFGIT (Apollo Field Geology Investigation Team): 1973,Science 182, 672–680.
Anderson, A. T., Brazunas, T. F., Jacoby, J., and Smith, J. V.: 1972,Proc. Third Lunar Sci. Conf. 1, 819–835.
Banerjee, S. K. and Swits, G.: 1975, this issue, p. 473.
Bence, A. E., Papike, J. J., Sueno, S. S., and Delano, J. W.: 1973,Proc. Fourth Lunar Sci. Conf. 1, 597–611.
Blanchard, D. P., Haskin, L. A., Jacobs, J. W., Brannon, J. C., and Korotev, R. L.: 1974,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 211D, pp. IV-1–IV-12.
Blanchard, D. P., Haskin, L. A., Jacobs, J. W., Brannon, J. C., and Korotev, R. L.: 1975, this issue p. 359.
Compston, W., Foster, J. J., and Gray, C. M.: 1975, this issue, p. 445.
Grieve, R. A., McKay, G. A., Smith, H. D., and Weill, D. F.: 1975,Geochim. Cosmochim. Acta 39, 229–245.
Hallam, M. E.: 1974,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 210D, pp. 111–120.
Heiken, G. H., Butler, P., Phinney, W. C., Warner, J., Schmitt, H. H., Bogard, D. D., Simonds, C. H., and Pearce, W. G.: 1973,NASA Tech. Mem. X-58116, 56 pp.
Husain, L. and Schaeffer, O. A.: 1975,Geophys. Res. Letters 2, 29–32.
James, O. B., Marti, K., Braddy, D., Hutcheon, I. D., Brecher, A., Silver, L. T., Blanchard, D. P., Jacobs, J. W., Brannon, J. C., Korotev, R. L., and Haskin, L. A.: 1975,Lunar Science VI, The Lunar Science Institute, pp. 435–437.
Leich, D. A., Kahl, S. B., Kirschbaum, A. R., Niemeyer, S., and Phinney, D.: 1974,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 211D, pp. VI-1–VI-18.
Levin, E. M., Robbins, C. R., and McMurdie, H. F.: 1964,Phase Diagrams for Ceramists, Am. Ceramic Soc., Columbus, Ohio, p. 158.
Marvin, U. B.: 1974,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 210D, pp. 9–33.
Marvin, U. B.: 1975, this issue, p. 315.
Marvin, U. B., Stoeser, D. B., and Bower, J. F.: 1974,Meteoritics 9, 377–379.
McCallum, I. S., Mathez, E. Z., Okamura, F. P., and Ghose, S.: 1975,Lunar Science VI, The Lunar Science Institute, pp. 534–536.
Morgan, J. W., Higuchi, H., and Anders, E.: 1975, this issue, p. 373.
PET (Apollo 17 Preliminary Examination Team): 1973,Science 182, 659–672.
Prinz, M., Dowty, E., Keil, K., and Bunch, T. E.: 1973,Geochim. Cosmochim. Acta 37, 979–1006.
Ryder, G., Stoeser, D. B., Marvin, U. B., and Bower, J. F.: 1975,Proc. Sixth Lunar Sci. Conf., in press.
Schmitt, H. H.: 1973,Science 182, 681–690.
Schmitt, H. H.: 1975, this issue, p. 491.
Simonds, C. H., Warner, J. L., and Phinney, W. C.: 1973,Proc. Fourth Lunar Sci. Conf. 1, 613–632.
Stoeser, D. B., Marvin, U. B., and Bower, J. F.: 1974a,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 211D, pp. III-1–III-51.
Stoeser, D. B., Wolfe, R. W., Wood, J. A., and Bower, J. F.: 1974b,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 210D, pp. 35–109.
Stoeser, D. B., Marvin, U. B., Wood, J. A., Wolfe, R. W., and Bower, J. F.: 1974c,Proc. Fifth Lunar Sci. Conf. 1, 355–377.
Taylor, G. J., Marvin, U. B., Reid, J. B., Jr., and Wood, J. A.: 1972,Proc. Third Lunar Sci. Conf. 1, 995–1014.
Walker, D., Grove, T. L., Longhi, J., Stolper, E. M., and Hays, J. F.: 1973,Earth Planetary Sci. Letters 20, 235–236.
Warner, J. L.: 1972,Proc. Third Lunar Sci. Conf. 1, 623–643.
Wilshire, H. G. and Jackson, E. D.: 1972,Earth Planetary Sci. Letters 16, 396–400.
Wolfe, E. W. and Reed, V. S.: 1974,Interdisciplinary Studies of Samples from Boulder 1, Station 2, Apollo 17, L.S.I. Contr. No. 211D, pp. I-1–I-19.
Wood, J. A.: 1975, this issue, p. 505.
Wood, J. A., Marvin, U. B., Reid, J. B., Jr., Taylor, G. J., Bower, J. F., Powell, B. N., and Dickey, J. S., Jr.: 1971,SAO Special Rept. 333, 272 pp.