New study finds ice is better at dissolving iron than liquid water
In a result that could have a direct bearing on trying to understand the inexplicable geology of Mars, a new study has found that ice actually does a better job at releasing iron from mineral deposits than liquid water.
It was once believed that when iron-rich mineral deposits were locked in ice, the iron would stay put, but a new study from Sweden’s Umeå University shows that the ice itself is actually working better than permafrost melt to release the iron. The study showed that ice at -10 °C (14 °F) releases more iron from mineral deposits than liquid water at 4 °C (39.2 °F). “It may sound counterintuitive, but ice is not a passive frozen block,” says study co-author Jean-François Boily. “Freezing creates microscopic pockets of liquid water between ice crystals. These act like chemical reactors, where compounds become concentrated and extremely acidic. This means they can react with iron minerals even at temperatures as low as minus 30 degrees Celsius.”
The researchers also found that the seasonal freeze/thaw cycle helped this process, and that brackish fresh water did better in dissolving the iron than seawater.
The significance for Mars geology is that this suggests glacial ice in the alien Mars climate might be the catalyst for creating its meandering canyons that so much resemble features on Earth produced by liquid water. On Mars however no model yet has been convincingly successful in creating past conditions where liquid water could flow on the surface. Mars has either been is too cold or its atmosphere too thin to allow it.
This study suggests ice however could do the work. It also fits with other Martian data that suggests the same, that at the base of the Martian glaciers pockets of liquid water could exist that act to shape the canyons.
All of this is speculation on my part, but it seems that the planetary scientists who are studying Mars should take a close look at this research.
In a result that could have a direct bearing on trying to understand the inexplicable geology of Mars, a new study has found that ice actually does a better job at releasing iron from mineral deposits than liquid water.
It was once believed that when iron-rich mineral deposits were locked in ice, the iron would stay put, but a new study from Sweden’s Umeå University shows that the ice itself is actually working better than permafrost melt to release the iron. The study showed that ice at -10 °C (14 °F) releases more iron from mineral deposits than liquid water at 4 °C (39.2 °F). “It may sound counterintuitive, but ice is not a passive frozen block,” says study co-author Jean-François Boily. “Freezing creates microscopic pockets of liquid water between ice crystals. These act like chemical reactors, where compounds become concentrated and extremely acidic. This means they can react with iron minerals even at temperatures as low as minus 30 degrees Celsius.”
The researchers also found that the seasonal freeze/thaw cycle helped this process, and that brackish fresh water did better in dissolving the iron than seawater.
The significance for Mars geology is that this suggests glacial ice in the alien Mars climate might be the catalyst for creating its meandering canyons that so much resemble features on Earth produced by liquid water. On Mars however no model yet has been convincingly successful in creating past conditions where liquid water could flow on the surface. Mars has either been is too cold or its atmosphere too thin to allow it.
This study suggests ice however could do the work. It also fits with other Martian data that suggests the same, that at the base of the Martian glaciers pockets of liquid water could exist that act to shape the canyons.
All of this is speculation on my part, but it seems that the planetary scientists who are studying Mars should take a close look at this research.