Origin of small pits in martian impact craters

Joseph M. Boyce, Lionel Wilson, Peter J. Mouginis-Mark, Christopher W. Hamilton, Livio L. Tornabene

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

We propose a numerical model for the formation of the closely-spaced pits found in the thin, ejecta-related deposits superposed on the floors, interior terrace blocks, and near-rim ejecta blankets of well-preserved martian impact craters. Our model predicts the explosive degassing of water from this pitted material, which is assumed to originally be water-bearing, impact melt-rich breccia at the time of deposition. This process is analogous to what occurred in the fall-out suevite deposits at the Ries impact structure in Germany. At Ries, impact heating of water-bearing target material resulted in the rapid degassing of its water and other volatiles. The martian environment plays an important role in enhancing the effects of this degassing by increasing the flow-speed of the escaping gas. The high flow-rate of gas through particulate materials, such as suevite, tends to quickly form segregation channels or vent pipes, similar to those found in the Ries deposits. These pipes act as conduits for the efficient high-speed escape of the gas and small clasts that it entrains. Escaping gas and entrained clasts abraded and eroded the conduit walls, flaring them to form pits above a network of pipes.

Original languageEnglish (US)
Pages (from-to)262-275
Number of pages14
JournalIcarus
Volume221
Issue number1
DOIs
StatePublished - Sep 1 2012
Externally publishedYes

Keywords

  • Cratering
  • Geological processes
  • Impact processes
  • Mars, Surface
  • Terrestrial planets

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Origin of small pits in martian impact craters'. Together they form a unique fingerprint.

  • Cite this

    Boyce, J. M., Wilson, L., Mouginis-Mark, P. J., Hamilton, C. W., & Tornabene, L. L. (2012). Origin of small pits in martian impact craters. Icarus, 221(1), 262-275. https://doi.org/10.1016/j.icarus.2012.07.027