Red/violet contrast reversal on Mars - significance for eolian sediments

Journal Article · Tue Apr 01 00:00:00 EST 1986 · Icarus; (United States)

DOI:https://doi.org/10.1016/0019-1035(86)90005-9· OSTI ID:5265432

Thomas, P; Veverka, J

Viking Orbiter images of Mars are analyzed to define relationships between the observed contrast reversals (CR) and specific surface features. The link between CR phenomena and surface composition was first detected in contrast comparisons between UV and visible wavelength Mariner 9 data. Viking data, taken through red and violet filters, showed that the CRs occurred only with crater splotches and splotch-related streaks and in bright depositional and dark erosional streaks, both being low-albedo markings presumably caused by eolian forces. The splotch phenomena is confined mainly to the Oxia Palus region, although there are other regions where splotches and streaks commingle. Laboratory tests to mimic the CR characteristics showed that CRs are a common phenomena of different size fractions of iron oxides, e.g., goethite, where particles under 5 microns have been removed. The splotches, including dune formations, are therefore believed to indicate the presence of particles in the 100-800 microns diam range. Finer particles ride on the tops of the dust storms, and are continually removed from the surface by saltation. 51 references.

• Research Organization: Cornell Univ., Ithaca, NY
• OSTI ID: 5265432
• Journal Information: Icarus; (United States), Vol. 66
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MARS PLANET
SEDIMENTS
ALBEDO
IMAGES
IRON OXIDES
PARTICLE SIZE
STORMS
VIKING SPACE PROBES
CHALCOGENIDES
DISASTERS
IRON COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANETS
SIZE
SPACE VEHICLES
TRANSITION ELEMENT COMPOUNDS
VEHICLES
640107* - Astrophysics & Cosmology- Planetary Phenomena