Abstract
New Hugoniot and release adiabate data for 1.8 g cm−3 lunar fines (sample, 70051) in the ç2 to ç70 kbar range demonstrate that upon shock compression intrinsic crystal density (ç3.1 g cm−3) is achieved undershock stresses of 15 to 20 kbar. Release adiabate determinations indicate that measurable irreversible compaction occurs upon achieving shock pressures above ç4 kbar. For shocks in the ç7 to 15 kbar range, the inferred,post-shock, specific volumes observed decrease nearly linearly with increasing peak shock pressures. Upon shocking to ç15 kbar the post-shock density is approximately that of the intrinsic minerals. If the present data for sample 70051 are taken to be representative of the response to impact of unconsolidated regolith material on the Moon, it is inferred that the formation of appreciable quantities of soil breccia can be associated with the impact of meteoroids or ejecta at speeds of as low as ç1 km s−1.
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Ahrens, T. J. and Cole, D. M.: 1974,Proc. Fifth Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 5,3, 2335–2344.
Ahrens, T. J. and Gregson, V. G.: 1964,J. Geophys.Res. 69, 4389–4874.
Ahrens, T. J., Lower, J. H., and Lagus, P. L.: 1971,J. Geophys. Res. 76, 518–530.
Ahrens, T. J., Petersen, C. F., and Rosenberg, T. J.: 1969,J. Geophys. Res. 74, 2727–2746.
Baldwin, R. B.: 1963,The Measure of the Moon, University of Chicago Press, Chicago.
Christie, J. M., Griggs, D. T., Heuer, A. H., Nord, G. L., Jr., Radcliffe, S. V., Lally, J.S., and Fisher, R. M.: 1973,Proc. Fourth Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 4,1, 365–832.
Gault, D. E. and Heitowit, E. D.: 1963,Proc. Sixth Hypervelocity Impact Symposium, Cleveland, Ohio, Vol. 2, pp. 419-456, (unpublished).
Gault, D. E., Hörz, F., Brownlee, D. E., and Hartung, J. B.: 1974,Proc. Fifth Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 5,3, 2365–2386.
Hartmann, W. K. and Wood, C. A.: 1971,The Moon 3, 3–78.
Hörz, F.: 1969,Contr. Mineral. Petrol. 21, 365–377.
Kieffer, S. W.: 1975,The Moon, in press.
LSPET (Lunar Sample Preliminary Examination Team): 1972,Apollo 15 Preliminary Science Report, NASA SP-289, pp. 6-1-25, U. S. Government Printing Office.
LSPET (Lunar Sample Preliminary Examination Team): 1973,Apollo 17 Preliminary Science Report, NASA SP-300, pp. 7-1-46 U.S. Government Printing Office.
McGetchin, T. R., Settle M., and Head, J. W.: 1973,Earth Planetary Sci. Letters 20, 226–236.
McQueen, R. G., Marsh, S. P., Taylor, J. W., Fritz, J. N., and Carter, W. J.: 1970, in R. Kinslow (ed.),High-Velocity Impact Phenomena, pp. 293-417, Academic Press.
Moore, H. J.: 1966,U.S.G.S. Report, November, pp. 79-106.
Moore, H. J.: 1975,U.S.G.S. Professional Paper (to be published).
Moore, H. J., Gault, D. E., and Lugn, R. V.: 1963,Trans. Mining Engineers, pp. 258-262.
O'Keefe, J. D. and Ahrens, T. J.: 1975,Proc. Sixth Lunar Sci. Conf., (in press).
Pike, P. J.: 1974,Earth Planetary Sci. Letters 23, 265–274.
Schmitt, H. H. and Cernan, E. A.: 1973,Apollo 17 Preliminary Science Report, NASA SP-300, pp. 5-1-21.
Tera, F., Papanastassiou, D. A., and Wasserburg, G. J.: 1974,Earth Planetary Sci. Letters 22, 1–21.
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Contribution No. 2626, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, Calif., U.S.A.
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Ahrens, T.J. Compaction by impact of unconsolidated lunar fines. The Moon 14, 291–299 (1975). https://doi.org/10.1007/BF00565328
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DOI: https://doi.org/10.1007/BF00565328