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Published October 1975 | public
Journal Article

Compaction by impact of unconsolidated lunar fines

Abstract

New Hugoniot and release adiabate data for 1.8 g cm^(−3) lunar fines (sample, 70051) in the ~2 to ~70 kbar range demonstrate that upon shock compression intrinsic crystal density (~3.1 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 ~4 kbar. For shocks in the ~7 to 15 kbar range, the inferred,post-shock, specific volumes observed decrease nearly linearly with increasing peak shock pressures. Upon shocking to ~15 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 ~1 km s^(−1).

Additional Information

© 1975 D. Reidel Publishing Company, Dordrecht-Holland. Received 27 June, 1975. Contribution No. 2626, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, Calif., U.S.A. Both the continued operation of the shock wave facility by H. Richeson and D. Johnson, and comments on some aspects of this work by R. Bryson and S. Bless are apprecia ted . J am grateful to R. G. McQueen {LASL) for allowing me to quote the lexan data. This research was supported by NASA Contract GR-05-002-307.

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023