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Carbonate Minerals in Nili Fossae
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Carbonate Minerals in Nili Fossae

Acquired Date: February 20, 2008
Release Date: April 4, 2014
Latitude: 21.28 N
Longitude: 78.51 E
Keywords: Fracture/Faults, Carbonate Mineral, Phyllosilicate minerals, Dichotomy Boundary
Parameters: BD2210 (Al-OH minerals), BD2500H2 (Mg-carbonates), D2300 (Fe-Mg phyllosilicates)

This image shows a site near Nili Fossae, a group of long, narrow tectonic depressions called graben, and reveals the presence of hydrated iron-magnesium (green) phyllosilicate and carbonate minerals (shown in yellow). Phyllosilicates, which include clay and clay-like minerals, form from the chemical reaction of water with igneous rocks. Carbonates form where carbon dioxide combines with the rocks. Minerals that formed by the chemical interaction of water or carbon dioxide with igneous rocks record information about the past environment in which the reactions occurred, and therefore are high science priority targets for future exploration of Mars. The areas shown in purple/blue contain aluminum-rich minerals, where circulating water may have partially flushed the iron and magnesium from the rock.



This image shows a site near Nili Fossae, a group of long, narrow tectonic depressions called graben, and reveals the presence of hydrated iron-magnesium (green) phyllosilicate and carbonate minerals (shown in yellow). Phyllosilicates, which include clay and clay-like minerals, form from the chemical reaction of water with igneous rocks. Carbonates form where carbon dioxide combines with the rocks. Minerals that formed by the chemical interaction of water or carbon dioxide with igneous rocks record information about the past environment in which the reactions occurred, and therefore are high science priority targets for future exploration of Mars. The areas shown in purple/blue contain aluminum-rich minerals, where circulating water may have partially flushed the iron and magnesium from the rock.

The recurring pattern of aluminum-rich phyllosilicates overlying iron/magnesium-rich phyllosilicates is something that we see on Earth as well. Aluminum-rich phyllosilicates can form by leaching of soluble elements from soil, whereas iron/magnesium-rich phyllosilicates are closer in composition to the parent volcanic rock. This layering of minerals may imply that more soluble elements (like iron and magnesium) were leached from overlying rocks, creating a residue of aluminum-phyllosilicates overlying less-leached iron-magnesium phyllosilicates.

Link to further description of the spectral parameters shown in this image

Disclaimer: Colors shown here represent indicators of mineralogy and are not what the human eye would see.

Acknowledgements: THEMIS, MOLA, CRISM, Google Earth.

References: Ehlmann et al., 2009 (Journal of Geophysical Research Planets)

The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad.

CRISM's mission: Find the spectral fingerprints of aqueous and hydrothermal deposits and map the geology, composition and stratigraphy of surface features. The instrument also tracks seasonal variations in dust and ice aerosols in the Martian atmosphere, and water content in surface materials — leading to new understanding of the climate.

Credit: NASA/JPL/JHUAPL

   

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