Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Circular Thin Area

  • Lauren Edgar
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_56


Thin crust surrounded by rings of thicker crust in crustal thickness model data.


Areas of thinner crust surrounded by rings of thicker crust. Possible buried impact basins that are often not detectable by topographic data or optical imagery alone. Circular thin areas (CTAs) are detected in crustal thickness data, derived from gravity field and topographic data.


Roughly circular, large areas of thinner crust, surrounded by thicker crust.


Possible buried impact basins.


Impact cratering


Impact craters are degraded and buried over time through a number of processes. The extent of burial determines whether they can be detected in topographic data (as QCDs) and/or in crustal thickness models (as CTAs) (Figs. 1 and 2). Due to its longer and more active geologic history, Mars has more ways to degrade and bury impact craters than does the Moon (Frey 2011). Impact ejecta from large basins is thought to contribute to burial...
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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

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