Lunar Crater Ina: Analysis of the Morphology of Intracrater Landforms


We present the results of geological and morphological analysis of LROC NAC images of a small volcanic crater Ina, D-shaped in plan view (2.9 × 1.9 km), and its immediate surroundings. This crater is located at the top of a very gently sloping shield volcano, the slopes of which, judging by the density of superimposed small craters, were formed ~3.5 Ga ago. Inside the crater there is a region with uneven relief and low hills, the density of small craters on which corresponds to an age of <100 Ma. In a number of works, the formations inside the Ina crater are considered to be manifestations of very young volcanism, while in other works, hills with an apparent age of <100 Ma are considered to be composed of “magmatic foam” such as massive pumice, which could affect the formation of small craters on them, reducing their diameters and thereby underestimating their measured spatial density. Accordingly, the Ina crater may be ancient and have the same age as the slopes of the shield volcano. In this paper, we studied the degree of morphological “freshness” of formations inside the Ina structure and compared the morphology of small craters superimposed on the hills inside Ina and on the slopes of the shield volcano adjacent to the Ina structure. In addition, model calculations of the thickness of the regolith layer for the cases of a “normal” target and a target consisting of “magmatic foam” have been performed. It is shown that the morphological freshness of the formations inside the Ina crater does not agree with the assumption about the ancientry of this crater, and morphologically “fresh” small craters on the hills inside Ina barely differ from those on the slopes of the shield volcano. These observations appear to contradict the “magmatic foam” hypothesis and support the conclusion that Ina’s structure is young.

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  1. 1

    Arvidson, R., Drozd, R.J., Hohenberg, C.M., Morgan, C.J., and Poupeau, G., Horizontal transport of the regolith, modification of features, and erosion rates on the lunar surface, Moon, 1975, vol. 13, pp. 61–79.

    ADS  Google Scholar 

  2. 2

    Bart, G.D., Nickerson, R.D., Lawder, M.T., and Melosh, H., Global survey of lunar regolith depths from LROC images, Icarus, 2011, vol. 215, no. 2, pp. 485–490.

    ADS  Article  Google Scholar 

  3. 3

    Basilevsky, A.T., Florensky, C.P., and Ronca, L.B., A possible lunar outcrop: A study of Lunokhod-2 data, Moon, 1977, vol. 17, pp. 19–28.

    ADS  Article  Google Scholar 

  4. 4

    Basilevsky, A.T., Michael, G.G., Krasilnikov, S.S., and Kozlova, N.A., Mechanisms of destructions of small craters of the moon, Sol. Syst. Res., 2020, vol. 54, no. 5, pp. 387–396.

    Article  Google Scholar 

  5. 5

    Bennett, K.A., Horgan, B.H.N., Bell III, J.F., Meyer, H.M., and Robinson, M.S., Moon mineralogy mapper investigation of the Ina irregular mare patch, The 46th Lunar and Planet. Sci. Conf., 2015, abs. 2646.

  6. 6

    Braden, S.E., Stopar, J.D., Robinson, M.S., Lawrence, S.J., van der Bogert, C.H., and Hiesinger, H., Evidence for basaltic volcanism on the Moon within the past 100 million years, Nat. Geosci., 2014, vol. 7, pp. 787–791.

    ADS  Article  Google Scholar 

  7. 7

    Elder, C.M., Hayne, P.O., Bandfield, J.L., Ghent, R.R., Williams, J.P., Donaldson, Hanna, K.L., and Paige, D.A., Young lunar volcanic features: Thermophysical properties and formation, Icarus, 2017, vol. 290, pp. 224–237.

    ADS  Article  Google Scholar 

  8. 8

    Evans, R.E. and El-Baz, F., Geological observations from lunar orbit, in Apollo 17 Preliminary Sci. Rep. NASA SP 330, 1973, pp. 28-1–28-32.

  9. 9

    Florenskii, K.P., Bazilevskii, A.T., Bobina, N.N., Burba, G.A., Grebennik, N.N., Kuz’min, R.O., Polosukhin, V.P., Popovich, V.D., and Pronin, A.A., Processes of transformation of the lunar surface in the Lemonnier region based on the results of a detailed study on Lunokhod-2, in Tektonika i Strukturnaya Geologiya. Planetologiya (Tectonics and Structural Geology. Planetology), Moscow: Nauka, 1976, pp. 205–234.

  10. 10

    Garry, W.B., Robinson, M.S., Zimbelman, J.R., Bleacher, J.E., Hawke, B.R., Crumpler, L.S., Braden, S.E., and Sato, H., The origin of Ina: Evidence for inflated lava flows on the Moon, J. Geophys. Res.: Planets, 2012, vol. 117.

  11. 11

    Green, R.O., Pieters, C.V., Mouroulis, P., et al., The Moon Mineralogy Mapper (M3) imaging spectrometer for lunar science: Instrument description, calibration, on-orbit measurements, science data calibration and on-orbit validation, J. Geophys. Res.: Planets, 2011, vol. 116, no. E10.

  12. 12

    Grice, J., Donaldson Hanna, K.L., Bowles, N.E., Schultz, P.H., and Bennett, K.A., Investigating young (<100 million years) irregular mare patches on the Moon using Moon Mineralogy Mapper observations, The 47th Lunar and Planet. Sci. Conf., 2015, abs. 2106.

  13. 13

    Hiesinger, H., Head III, J., Wolf, W.U., Jaumann, R., and Neukum, G., Ages and stratigraphy of mare basalts in Oceanus Procellarum, Mare Nubium, Mare Cognitum, and Mare Insularum, J. Geophys. Res.: Planets, 2003, vol. 108, no. E7.

  14. 14

    Housen, K.R., Sweet, W.J., and Holsapple, K.A., Impacts into porous asteroids, Icarus, 2018, vol. 300, pp. 72–96.

    ADS  Article  Google Scholar 

  15. 15

    Ivanov, B.A. and Head, J.W., Impacts into magmatic foam and the age of irregular mare patches: Experimental data, interpretations, and outstanding questions, The 50th Lunar and Planet. Sci. Conf., 2019, abs. 1243.

  16. 16

    McKay, D.S., Heiken, G., Basu, A., Blanford, G., Simon, S., Reedy, R., French, B.M., and Papike, J., 7. The lunar regolith. 7.3. Regolith evolution and maturity, in Lunar Source Book. A User’s Guide to the Moon, Cambridge Univ. Press, 1991, pp. 307–321.

    Google Scholar 

  17. 17

    Michael, G., Basilevsky, A., and Neukum, G., On the history of the early meteoritic bombardment of the Moon: Was there a terminal lunar cataclysm?, Icarus, 2018, vol. 302, pp. 80–103.

    ADS  Article  Google Scholar 

  18. 18

    Neukum, G., Ivanov, B., and Hartmann, W.K., Cratering records in the inner solar system in relation to the lunar reference system, Space Sci. Rev., 2001, vol. 96, pp. 55–86.

    ADS  Article  Google Scholar 

  19. 19

    Neukum, G., Meteoriten bombardement und Datierung planetarer Oberflachen, Habilitation Thesis for Faculty Membership, Univ. of Munich, 1983.

  20. 20

    Qiao, L., Head, J.W., Ling, Z., Wilson, L., Xiao, L., Dufek, J.D., and Yan, J., Geological characterization of the Ina shield volcano summit pit crater on the Moon: Evidence for extrusion of waning-stage lava lake magmatic foams and anomalously young crater retention ages, J. Geophys. Res.: Planets, 2019, vol. 124, pp. 1100–1140.

    ADS  Article  Google Scholar 

  21. 21

    Qiao, L., Head, J.W., Wilson, L., and Ling, Z., The Cauchy 5 small, low-volume lunar shield volcano: Evidence for volatile exsolution-eruption patterns and Type 1/Type 2 hybrid Irregular Mare Patch formation, J. Geophys. Res.: Planets, 2020, vol. 125, no. 2.

  22. 22

    Qiao, Le., Head, J., Wilson, L., Xiao, L., Kreslavsky, M., and Dufek, J., Ina pit crater on the Moon: Extrusion of waning-stage lava lake magmatic foam results in extremely young crater retention ages, Geology, 2017, vol. 45, no. 5, pp. 455–458.

    ADS  Article  Google Scholar 

  23. 23

    Robinson, M.S., Brylow, S.M., Tschimmel, M., et al., Lunar Reconnaissance Orbiter Camera (LROC) instrument overview, Space Sci. Rev., 2010a, vol. 150, nos. 1–4, pp. 81–124.

    ADS  Article  Google Scholar 

  24. 24

    Robinson, M.S., Thomas, P.C., Braden, S.E., Lawrence, S.J., and Garry, W.B., High resolution imaging of Ina: Morphology, relative ages, formation, Lunar Planet. Sci. XLI, 2010b, abs. 2592.

  25. 25

    Schultz, P.H., Anderson, J.L.B., and Heineck, J.T., Impact crater size and evolution: Expectations for Deep Impact, 33rd Lunar and Planet. Sci. Conf., 2002, abs. 1875

  26. 26

    Schultz, P.H., Staid, M.I., and Pieters, C.M., Lunar activity from recent gas release, Nature, 2006, vol. 444, pp. 184–186.

    ADS  Article  Google Scholar 

  27. 27

    Shkuratov, Yu.G. and Bondarenko, N.V., Regolith layer thickness mapping of the Moon by radar and optical data, Icarus, 2001, vol. 149, no. 2, pp. 329–338.

    ADS  Article  Google Scholar 

  28. 28

    Swann, G.A., Bailey, N.G., Batson, R.M., et al., 3. Preliminary geologic investigations of the Apollo 14 landing site, in Apollo 14 Preliminary Science Report. NASA SP-272, 1971, pp. 39–85.

  29. 29

    Valantinas, A., Kinch, M., and Bridžius, A., Low crater frequencies and low model ages in lunar maria: Recent endogenic activity or degradation effects?, Meteorit. Planet. Sci., 2018, vol. 53, pp. 826–838.

    ADS  Article  Google Scholar 

  30. 30

    Wasserburg, G.J. and Papanastassiou, D.A., Age of Apollo 15 mare basalt: Lunar crust and mantle evolution, Earth Planet. Sci. Lett., 1971, vol. 1, pp. 97–104.

    ADS  Article  Google Scholar 

  31. 31

    Whitaker, E.A., An unusual mare feature, NASA Spec. Publ., 1972, vol. 289, pp. 25–84.

    Google Scholar 

  32. 32

    Wilson, L. and Head, J.W., Eruption of magmatic foams on the Moon: Formation in the waning stages of dike emplacement events as an explanation of “irregular mare patches,” J. Volcanol. Geotherm. Res., 2017, vol. 335, pp. 113–127.

    ADS  Article  Google Scholar 

  33. 33

    Wunnemann, K., Collins, G.S., and Melosh, H.J., A strain-based porosity model for use in hydrocode simulations of impacts and implications for transient crater growth in porous targets, Icarus, 2006, vol. 180, pp. 514–527.

    ADS  Article  Google Scholar 

  34. 34

    Wunnemann, K., Collins, G.S., and Osinski, G.R., Numerical modelling of impact melt production in porous rocks, Earth Planet. Sci. Lett., 2008, vol. 269, pp. 530–539.

    ADS  Article  Google Scholar 

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The authors are grateful to M.A. Kreslavsky and a second anonymous referee, whose comments and suggestions helped to significantly improve this work.

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Correspondence to A. T. Basilevsky.

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Translated by E. Seifina

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Basilevsky, A.T., Michael, G.G. Lunar Crater Ina: Analysis of the Morphology of Intracrater Landforms. Sol Syst Res 55, 20–30 (2021).

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  • volcanic crater
  • basalt
  • magmatic foam
  • regolith
  • lateral transport