Mars analogue found in India
doi:10.1038/nindia.2010.15 Published online 19 February 2010
Matanumadh, a non-descript village in Gujarat in western India, has been catapulted to global fame thanks to a discovery by two geologists at the Wadia Institute of Himalayan Geology (WIHG) in Dehradun.
Their finding is likely to lead planetary scientists around the world to turn the spotlight on Matanumadh, a village 80 km northwest of Bhuj in the Kachchh region in particular, and the Deccan Volcanic Province (DVP) in general.
The WIHG scientists Neelam Siva Siddaiah and Kishor Kumar recently discovered here the presence of a calcium-bearing mineral called minamiite, belonging to the group 'hydrous sulphates' abundant in planet Mars but very rare on earth. "Matanumadh hydrous sulphates are similar to those found on the surface of Mars and we have found minamiite for the first time in India," the researchers report.
The Matanumadh discovery has raised the possibility that the entire Deccan Volcanic Province (DVP) spread over large tracts of west-central parts of India could be a potential 'analogue' for Mars, Siddaiah told Nature India. In fact, he says, it could be an 'outstanding analogue' since the Deccan basaltic volcanism on Earth and the volcanoes on Mars were produced by 'thermal plume' process (in which the volcanoes erupt due to a 'hotspot' below).
In the Gujarat village the researchers found the occurrence of hydrous sulphates as layers within sandstone units overlying the Deccan traps. The sulphate layers are reportedly up to a metre thick, white to cream-yellow and reddish in colour, and extend laterally for over a kilometre on both sides of Matanumadh–Lakhpat road. The scientists collected several bulk samples from outcrops. Minamiite was identified in them by X-ray diffraction and chemical analyses.
According to Siddaiah, discovery of hydrous sulphates by NASA's Mars Exploration Rovers stimulated worldwide interest in studying the Martian analogues on Earth in order to elucidate the mineralogical and chemical makeup of the Martian surface, and to get insights into the processes that may have operated on Mars.
Siddaiah says several sites such as Rio Tinto and Jaroso Ravine (Spain), Dry Valleys (Antarctica), Devon Island (Canada), Valley of Ten Thousand Smokes (USA), and Payun Matru Volcanic complex (Argentina), among others, are under investigation the world over. Minamiite has been reported only from a few places such as an ancient subvolcanic hydrothermal system exposed at Mt. Schimkura in northeastern Japan, in the volcanics of southwest Turkey, and from volcanoes of the Cascade Range in Western USA. Matanumadh is the first place in India where the mineral has been found.
The Matnumadh hydrous sulphate deposits consist dominantly of minamiite and another mineral natroalunite. The mineralogy, texture and mineral stability suggest that these hydrous sulphates could be a product of reactions between volcanic gases and acidic hydrothermal solutions with the volcanic ash/rock, the report said.
"The DVP approximates the geological, geomorphological and environmental conditions on Mars and appears to be a promising analogue site for improving understanding of the Martian surface mineralogy, volcanism and related aqueous hydrothermal processes," the report concludes.
Although minamiite has specifically so far not been reported from Mars, the occurrence of hydrous sulphates in general in Mars indicates the presence of aqueous conditions on the planet, Siddaiah explained. "The central idea of our contribution is that until such time we get technological ability for direct access to Martian samples, we will have to depend on Earth analogues such as the DVP", he said.
Several scientists abroad working on planetary exploration agree. "I believe that the DVP makes an exceptional Mars/Earth analogue area and is currently under-utilized for such investigations," Mikki Osterloo of the University of Hawaii at Manoa has written to Siddaiah.
Ken Herkenhoff, who heads the Astrogeology Science Center of U. S. Geological Survey, also e-mailed Siddaiah saying the Indian discovery 'would be of interest' to his colleagues in the Mars Exploration Rovers programme.
- Siddaiah, N. S. et al. Discovery of minamiite from the Deccan Volcanic Province, India: implications for Martian surface exploration. Curr. Sci. 97, 1664-1669 (2009)