Coupled ferric oxides and sulfates on the Martian surface

Research areas:
Year:
2007
Authors:
Journal:
SCIENCE
Volume:
317
Number:
5842
Pages:
1206-1210
Month:
AUG 31
ISSN:
0036-8075
Abstract:
The Mars Exploration Rover ( MER), Opportunity, showed that layered
sulfate deposits in Meridiani Planum formed during a period of rising
acidic ground water. Crystalline hematite spherules formed in the
deposits as a consequence of aqueous alteration and were concentrated on
the surface as a lag deposit as wind eroded the softer sulfate rocks. On
the basis of Mars Express Observatoire pour la Mineralogie, l'Eau, les
Glaces et l'Activite ( OMEGA) orbital data, we demonstrate that
crystalline hematite deposits are associated with layered sulfates in
other areas on Mars, implying that Meridiani-like ground water systems
were indeed widespread and representative of an extensive acid sulfate
aqueous system.