A team headed by Catherine Weitz at Tucson's Planetary Science Institute reported at last week's AGU Fall Meeting that they found evidence for multiple processes on Mars that led to water-related geologic features being formed. Light-toned layered deposits (LLDs) "vary morphologically and mineralogically throughout Noctis Labyrinthus suggests that there may be multiple processes with variable amounts of groundwater that are responsible for emplacement and evolution of distinct units in each pit. Our results indicate that transient, isolated and relatively small bodies of water were capable of leading to the accumulation of LLDs in this region."
The team used images from the UA-run HiRISE camera on the Mars Reconnaissance Orbiter to make their determininations. [right, HiRISE image showing LLDs in a trough in the Noctis Labyrinthus region of Mars. Credit: NASA/Jet Propulsion Laboratory/The University of Arizona]
A story on Science Daily reports the researchers found evidence for a complex hydrologic history, involving multiple depositional events, and significant volumes of water.
Planetary Science Institute. "Trough Deposits on Mars Point to Complex Hydrologic Past." ScienceDaily 17 December 2009. 21 December 2009
Mineralogy and Morphology of Light-toned Layered Deposits in Pits of Noctis Labyrinthus
C. M. Weitz; J. L. Bishop; L. Roach; J. P. Rodriguez, ID# P21C-02