Lobate scarps and the Martian crustal dichotomy

Thomas R. Watters, Mark Robinson

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Landforms reflecting crustal shortening are found in the ancient highlands of the eastern hemisphere of Mars. These structures, referred to as lobate scarps, are interpreted to be thrust faults. Lobate scarps occur near and are oriented roughly parallel to the Martian crustal dichotomy, a major geologic and topographic boundary that divides the heavily cratered highlands from the relatively smooth, featureless northern lowlands. The long- and short-wavelength topography of lobate scarps in the northern Terra Cimmeria-Amenthes region have been analyzed using photoclinometry, Earth-based radar altimetry, and Mars Orbiter Laser Altimeter data. The measured relief of lobate scarps in this region ranges from ∼110 to 1230 m, and they occur on gentle regional slopes that dip both toward and away from the dichotomy. Estimates of the horizontal shortening across the lobate scarps studied range from roughly 0.24 to 2.6 km (n = 9), assuming fault plane dips of 25°. The displacement-length (D-L) relationships of thrust faults associated with the lobate scarps are consistent with those observed for terrestrial fault populations. The compressional strain in the heavily cratered highlands near the dichotomy, determined using the D-L data for the lobate scarps, is estimated to be ∼0.17%. Topographic data indicate that the dichotomy in the northern Terra Cimmeria-Amenthes region has a distinct topographic signature. The spatial and temporal relationship of the lobate scarps to the boundary suggests that they are related to its formation, supporting models for a tectonic origin of the crustal dichotomy.

Original languageEnglish (US)
Pages (from-to)18981-18990
Number of pages10
JournalJournal of Geophysical Research E: Planets
Volume104
Issue numberE8
StatePublished - Aug 25 1999
Externally publishedYes

Fingerprint

escarpments
dichotomies
thrust fault
Landforms
Wavelength
Aneroid altimeters
Mars
Tectonics
highlands
Topography
radar altimetry
wavelength
Radar
crustal shortening
Earth (planet)
altimeter
fault plane
landform
Lasers
dip

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Atmospheric Science
  • Geochemistry and Petrology
  • Geophysics
  • Oceanography
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Lobate scarps and the Martian crustal dichotomy. / Watters, Thomas R.; Robinson, Mark.

In: Journal of Geophysical Research E: Planets, Vol. 104, No. E8, 25.08.1999, p. 18981-18990.

Research output: Contribution to journalArticle

Watters, Thomas R. ; Robinson, Mark. / Lobate scarps and the Martian crustal dichotomy. In: Journal of Geophysical Research E: Planets. 1999 ; Vol. 104, No. E8. pp. 18981-18990.
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