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The Aristarchus impact event and the effects of target material

Published online by Cambridge University Press:  01 May 2009

John E. Guest
Affiliation:
University of London Observatory, Mill Hill Park, London NW7 2QS, U.K.
Paul D. Spudis
Affiliation:
University of London Observatory, Mill Hill Park, London NW7 2QS, U.K.

Abstract

The relatively well preserved, 42 km diameter lunar impact crater Aristarchus was excavated across the boundary between the Aristarchus Plateau and the mare plains. Previous geological mapping of the different ejecta facies associated with Aristarchus has shown that there are distinct morphological differences between ejecta emplaced on either side of the fault scarp that separates the plateau from the mare. One explanation of this observation is that ejecta behaved in different ways on emplacement depending on the original lithology of the excavated material. To test this proposal, we examine the pre-Aristarchus regional stratigraphy and identify the spectral signatures of each of the material's units. By comparing these data with analysis of the geology and spectral characteristics of the ejecta units, we are able to show the provenance of each of the mappable ejecta facies. The conclusions are consistent with the concept of the crater ejecta asymmetry being related to bedrock characteristics. Using geological mapping, spectral interpretation and present understanding of the impact cratering process, we reconstruct the impact event and suggest how such techniques could be used further to interpret the Moon's composition and history.

Type
Articles
Copyright
Copyright © Cambridge University Press 1985

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References

Boyce, J. M. 1976. Ages of flow units in the lunar nearside maria based on Lunar Orbiter IV photographs. Proceedings of the Lunar Science Conference 7th, 2717–28.Google Scholar
Croft, S. K. 1980. Cratering flow fields: Implications for the excavation and transient expansion stages of crater formation. Proceedings of the Lunar and Planetary Science Conference llth, 2347–78.Google Scholar
Davis, P. A. 1980. Iron and titanium distribution on the moon from orbital gamma-ray spectrometry with implications for crustal evolutionary models. Journal of Geophysical Research 85, 3209–24.CrossRefGoogle Scholar
De Hon, R. A. 1979. Thickness of the western mare basalts. Proceedings of the Lunar and Planetary Science Conference 10th, 2935–55.Google Scholar
Etchegaray-Ramirez, M. I., Metzger, A. E., Haines, E. L. & Hawke, B. R. 1983. Thorium concentrations in the lunar surface. IV. Deconvolution of the Mare Imbrium, Aristarchus and adjacent regions. Proceedings of the Lunar and Planetary Science Conference 13th, Journal of Geophysical Research 88, A52943.CrossRefGoogle Scholar
Gault, D. E., Quaide, W. L. & Oberbeck, V. R. 1968. Impact cratering mechanics and structures. In Shock Metamorphism of Natural Materials (ed. French, B. M. and Short, N. M.), pp. 8799. Baltimore: Mono Book Corp.Google Scholar
Guest, J. E. 1973. Stratigraphy of ejecta from the lunar crater Aristarchus. Geological Society of America Bulletin 84, 2873–94.2.0.CO;2>CrossRefGoogle Scholar
Guest, J. E. & Murray, J. B. 1969. Nature and origin of Tsiolkovsky crater, lunar farside. Planetary and Space Science 17, 121–41.CrossRefGoogle Scholar
Haines, E. L., Etchegaray-Ramirez, M. I. & Metzger, A. E. 1978. Thorium concentrations in the lunar surface. II. Deconvolution modeling and its application to the regions of Aristarchus and Mare Smythii. Proceedings of the Lunar and Planetary Science Conference 9th, 29853013.Google Scholar
Hawke, B. R. & Head, J. W. 1977. Impact melt on lunar crater rims. In Impact and Explosion Cratering (ed. Roddy, D. J., Pepin, R. O. and Merrill, R. B.), pp. 815–41. New York: Pergamon.Google Scholar
Hawke, B. R. & Head, J. W. 1978. Lunar KREEP volcanism: geologic evidence for history and mode of emplacement. Proceedings of the Lunar and Planetary Science Conference 9th, 3285–309.Google Scholar
Hawke, B. R., Lucey, P. G., Mccord, T. B., Pieters, C. M. & Head, J. W. 1983. Spectral studies of the Aristarchus region: Implications for the composition of the lunar crust (abstract). Lunar and Planetary Science XIV, 289–90.Google Scholar
Hawke, B. R., Maclaskey, D. & Mccord, T. B. 1979. Multispectral imaging of lunar crater deposits (abstract). Conference on the Lunar Highlands Crust, pp. 50–2. Houston: The Lunar and Planetary Institute.Google Scholar
Howard, K. A. 1975. Geologic Map of the Crater Copernicus. U.S. Geological Survey Miscellaneous Geologic Investigations Map 1840.Google Scholar
Howard, K. A. & Wilshire, H. G. 1975. Flows of impact melt at lunar craters. Journal of Research of the U.S. Geological Survey 3, 237–51.Google Scholar
Johnson, T. V., Mosher, J. A. & Matson, D. L. 1977. Lunar spectral units: a northern hemispheric mosaic. Proceedings of the Lunar and Planetary Science Conference 8th, 1013–28.Google Scholar
Lucey, P. G., Hawke, B. R., Mccord, T. B., Pieters, C. M. & Head, J. W. 1982. An unusual composition at the Aristarchus Plateau (abstract). Bulletin of the American Astronomical Society 14 (3), 756–7.Google Scholar
Mccord, T. B., Charette, M. P., Johnson, T. V., Lebofsky, L. A. & Pieters, C. 1971. Lunar spectral types. Journal of Geophysical Research 77, 1349–59.CrossRefGoogle Scholar
Mccord, T. B., Pieters, C. & Feierberg, M. A. 1976. Multispectral mapping of the lunar surface using ground-based telescopes. Icarus 29, 134.CrossRefGoogle Scholar
Metzger, A. E., Trombka, J. I., Peterson, L. E., Reedy, R. C. & Arnold, J. R. 1973. Lunar surface radioactivity: preliminary results of the Apollo 15 and 16 gamma-ray spectrometer experiments. Science 179, 800–3.CrossRefGoogle ScholarPubMed
Moore, H. J., Arthur, D. W. G. & Schaber, G. G. 1978. Yield strengths of flows on the Earth, Mars and Moon. Proceedings of the Lunar and Planetary Science Conference 9th, 3351–78.Google Scholar
Pieters, C. 1977. Characterization of lunar mare basalt types - II; Spectral classification of fresh mare craters. Proceedings of the Lunar Science Conference 8th, 1037–48.Google Scholar
Roddy, D. J. 1968. The Flynn Creek Crater, Tennessee. In Shock Metamorphism of Natural Materials (ed. French, B.-M. and Short, N. M.), pp. 291322. Baltimore: Mono Book Corp.Google Scholar
Roddy, D. J. 1977 a. Large-scale impact and explosion craters: Comparisons of morphological and structural analogs. In Impact and Explosion Cratering (ed. Roddy, D. J., Pepin, R. O. and Merril, R. B.), pp. 185246. New York: Pergamon Press.Google Scholar
Roddy, D. J. 1977 b. Pre-impact conditions and cratering processes at the Flynn Creek Crater, Tennessee. In Impact and Explosion Cratering (ed. Roddy, D. J., Pepin, R. O. and Merril, R. B.), pp. 277308. New York: Pergamon Press.Google Scholar
Roddy, D. J. 1979. Structural deformation at the Flynn Creek impact crater, Tennessee: A preliminary report on deep drilling. Proceedings of the Lunar Science Conference 10th, 2519–34.Google Scholar
Ryder, G. 1976. Lunar sample 15405: remnant of a KREEP basalt-granite differentiated pluton. Earth and Planetary Science Letters 29, 255–68.CrossRefGoogle Scholar
Schonfeld, E. & Meyer, C. 1973. The old Imbrium hypothesis. Proceedings of the Lunar Science Conference 4th, 125–38.Google Scholar
Schultz, P. H. & Mendell, W. 1978. Orbital infrared observations of lunar craters and possible implications for impact ejecta emplacement. Proceedings of the Lunar Science Conference 9th, 2857–83.Google Scholar
Shoemaker, E. M. 1962. Interpretation of lunar craters. In Physics and Astronomy of the Moon (ed. Kopal, Z.), pp. 283359. London: Academic Press.Google Scholar
Shoemaker, E. M., Batson, R. M., Holt, H. E., Morris, E. C., Rennilson, J. J. & Whitaker, E. A. 1968. Television observation from Surveyor VII. In Surveyor VII Mission Report, Part II. Science Results, pp. 976. Jet Propulsion Laboratory Technical Report no. 32–1264.Google Scholar
Shorthill, R. W. 1973. Infrared atlas charts of the eclipsed Moon. The Moon 7, 2245.CrossRefGoogle Scholar
Shreve, R. L. 1966. Sherman Landslide, Alaska. Science 154, 1639–43.CrossRefGoogle ScholarPubMed
Spudis, P. D. 1978. Composition and origin of the Apennine Bench Formation. Proceedings of the Lunar Science Conference 9th, 3379–94.Google Scholar
Strom, R. G. & Fielder, G. 1970. Multiphase eruptions associated with the lunar craters Tycho and Aristarchus. Communications of the Lunar Planetary Laboratory 150, 235–88.Google Scholar
Thompson, T. W. 1979. A review of earth-based radar mapping of the Moon. The Moon and Planets 20, 179–98.CrossRefGoogle Scholar
Whitaker, E. A. 1972. Lunar color boundaries and their relationship to topographic features. The Moon 4, 348–55.CrossRefGoogle Scholar
Whitford-Stark, J. L. & Head, J. W. 1980. Stratigraphy of Oceanus Procellarum basalts: Sources and styles of emplacement. Journal of Geophysical Research 85, 6579–609.CrossRefGoogle Scholar
Witotski, J. 1977. Dynamic ejecta parameters from high-explosive detonations. In Impact and Explosion Cratering (ed. Roddy, D. J., Pepin, R. O. and Merrill, R. B.), pp. 1101–21. New York: Pergamon Press.Google Scholar
Zisk, S. H., Hodges, C. A., Moore, H. J., Shorthill, R. W., Thompson, T. W., Whitaker, E. A. & Wilhelms, D. E. 1977. The Aristarchus-Harbinger region of the Moon: Surface geology and history from recent remote-sensing observations. The Moon 17, 5999.CrossRefGoogle Scholar