Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Quasi-Circular Depression

  • Lauren EdgarEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_288


A circular topographic depression that appears in a high-resolution topographic dataset but may not have a corresponding visual structure on the surface.



In the broad sense, all kinds of at least somewhat circular depressions in the gridded topographic dataset of Mars Orbiter Laser Altimeters or Lunar Orbiter Laser Altimeter are quasi-circular depressions (QCDs), visible or not. In a more strict sense, QCDs (or stealth/invisible QCDs) are only those evident depressions which have no structural representation in optical imagery, i.e., cannot be detected via photogeologic methods (Buczkowski 2007b) (Fig. 1). However, some stealth QCDs (sQCDs) are manifested as circular fractures (Ghent et al. 2012).
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  1. Buczkowski DL (2007) Comparing Quasi-Circular Depression (QCD) locations to Northern Lowland materials on Mars. Seventh International Conference on Mars # 3302Google Scholar
  2. Buczkowski DL, McGill GE (2002) Topography within circular grabens: implications for polygon origin, Utopia Planitia, Mars. Geophys Res Lett 29(7):1155. doi:10.1029/2001GL014100CrossRefGoogle Scholar
  3. Buczkowsky DL (2007) Stealth quasi-circular depressions (sQCDs) in the northern lowlands of Mars. J Geophys Res 112:E09002. doi:10.1029/2006JE002836Google Scholar
  4. Frey H (2008) Ages of very large impact basins on Mars: implications for the late heavy bombardment in the inner solar system. Geophys Res Lett 35:l13203. doi:10.1029/2008gl033515CrossRefGoogle Scholar
  5. Frey H (2011a) Previously unknown large impact basins on the moon: implications for lunar stratigraphy. In: Ambrose WA, Williams DA (eds) Recent advances and current research issues in lunar stratigraphy. The Geological Society of America. Special paper 477, pp 53–77CrossRefGoogle Scholar
  6. Frey HV (2011b) New candidate large lunar basins from Lola data. Lunar Planet Sci Conf 42, abstract #1190, HoustonGoogle Scholar
  7. Frey H, Sakimoto SEH, Roark JH (1999) Discovery of a 450 km diameter, multi-ring basin on Mars through analysis of MOLA topographic data. Geophys Res Lett 26(12):1657–1660CrossRefGoogle Scholar
  8. Frey H, Hutchison L, Sakimoto S, Roark J (2000) A large population of possible buried impact basins on mars revealed by MOLA topographic data. Lunar Planet Sci Conf XXXI, abstract #1736, HoustonGoogle Scholar
  9. Frey HV, Shockey KM, Frey EL, Roark JH, Sakimoto SEH (2001) A very large population of likely buried impact basins in the northern lowlands of Mars revealed by MOLA data. Lunar Planet Sci Conf XXXII, abstract #1680, HoustonGoogle Scholar
  10. Frey HV, Roark JH, Shockey KM, Frey EL, Sakimoto SEH (2002) Ancient lowlands on Mars. Geophys Res Lett 29(10):1384. doi:10.1029/2001GL013832Google Scholar
  11. Ghent RR, Anderson SW, Pithwala TM (2012) The formation of small cones in Isidis Planitia, Mars through mobilization of pyroclastic surge deposits. Icarus 217:169–183CrossRefGoogle Scholar
  12. Morrison SJ, Frey HV (2007) Crater densities in Noachis Terra: evidence for overlapping ejecta from Argyre and Hellas. Lunar Planet Sci Conf XXXVIII, abstract #1355, HoustonGoogle Scholar

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© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.U.S. Geological SurveyAstrogeology Science CenterFlagstaffUSA