Background

1
Martian Depressions Implications for Large
Scale Evaporite DepositsZackery E. Smith, Jason
A. Tullis, Kenneth F. SteeleArkansas Center for
Space and Planetary Science, University of
Arkansas, Fayetteville, Arkansas, 72701

• Discussion
• Possible sinkholes have been found in Kasei
  Vallis on Lunae
• Terra and where an albedo anomaly exists in the
  outwash plain.
• Albedo anomalies also occur in the outflow
  channels and/or
• outwash plains of Tiu, Simud, Mawrth, Ares, Lobo,
  and
• Shalbatana Valles.
• We have also successfully imported PDS formatted
  color
• Viking Data into a 3D GIS map. We will now be
  able to overlay
• PDS data onto this map allowing us to create a 3D
  digital
• elevation model of the entire planet superimposed
  on top of a
• geographic map.
• Conclusions and Future Work
• We have identified three other areas of interest
  in the search for
• sinkholes on Mars.

• Background
• There are several theories that state that
  Martian sinkholes as
• the result of large evaporite deposits and
  erosion are impossible.
• The past presence of large oceans as well as the
  detection of
• gypsum, halite, calcite, and clays in Martian
  meteorites seems to
• point toward the types of large scale deposits
  necessary to create
• this type of sinkhole.
• Introduction
• The focus area of this study is the Circum-Chryse
  outflow
• channels in Xanthe and Margaritifer, Terrae and
  Lunae Planum
• and their outwash plains in Chryse Planitiae.
  (Figure 1) Based
• upon gamma-spectroscopy studies of the surface,
  the area is
• believed to have a high subterranean water
  abundance.
• (Figure 2) The outflow channel beds of this area
  also contain a
• large number of depressions thought to be the
  result of a

Figure 1
a) PDS formatted Color Viking Data imported into
a GIS atlas, with the study area boxed in red.
b) Possible sinkholes in Kasei Vallis, Lunae
Planum, from MGS MOLA mapping data

• Methods
• Procedures
• Identify study area and guidelines to
  distinguish between
• impact, volcanic and sinkhole features
• Acquire remote sensor data from Mars Global
  Surveyor
• and incorporate into GIS atlas
• Sinkholes Occurring in Outflow Channels Beds
  will
• Be non symmetric
• Be deeper on the upstream side
• The outwash plains will have albedo
  anomalies
• The length to width ratio will be lower
  where the flow
• rates are lower
• References
• Bridges, J. C. and Grady, M. M. Evaporite
  mineral assemblages in the