Hydrous minerals on Mars as seen by the CRISM and OMEGA imaging spectrometers: Updated global view

Research areas:
Year:
2013
Authors:
Journal:
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
Volume:
118
Number:
4
Pages:
831-858
Month:
April
ISSN:
2169-9097
Abstract:
The surface of Mars has preserved the record of early environments in
which its basaltic crust was altered by liquid water. These aqueous
environments have survived in the form of hydrological morphologies and
alteration minerals, including clays and hydrated salts. Because these
minerals probe on Earth aqueous environments compatible with biotic
activity, understanding their formation processes on Mars is of great
exobiological relevance and also offers insight into Earth's now erased
ancient water environments. Using remote sensing, we conducted a
large-scale investigation of the distribution, composition, age, and
geomorphic settings of hydrous minerals on Mars, providing a sharpened
global view of the early aqueous environments and their evolution with
time. Aqueous alteration seems to have produced clays on a planetary
scale but these are found to be restricted to the oldest observable
terrains on Mars (approximate to 4Gyr). However, very diverse aqueous
environments have also been found which suggest widespread, complex
aqueous settings from the surface to kilometric depths, and spanning
over 1Gyr. By building a robust statistical sample of detections, the
global trends inferred here attempt to provide a broad view of our
current understanding of hydrous minerals on Mars and provide context
for more localized, in-depth analyses. Collectively, these trends
suggest that at least transient conditions have existed on Mars which
may have been favorable for pre-biotic to biotic activity.