A new origin story for Burns formation on Mars

There’s a cause that NASA’s Alternative rover explored Mars’s Meridiani Planum area for 14 years: The locale may maintain essential hints concerning the Crimson Planet’s early geology and setting.

The area’s Burns formation, a layer of sandstone embedded with spherules of hematite known as “blueberries,” is of explicit curiosity to scientists as a result of it exhibits hallmarks of liquid water and has a sulfur-rich composition that echoes options widespread throughout Mars. The Burns formation lies atop a skinny rock layer referred to as the Grasberg formation, and in a brand new examine printed within the Journal of Geophysical Analysis: Planets, Thomas McCollom and Brian Hynek suggest a novel, widespread origin story for the 2.

The thought relies on the latest discovering that the Burns and Grasberg rocks are chemically related, besides that the previous are enriched in magnesium and sulfate.

Beforehand, there have been two predominant hypotheses to elucidate the Burns formation’s chemical composition. One household of fashions steered that the unique sands have been a mixture of historic silicates and sulfate salts of iron, magnesium, and calcium that precipitated from evaporating groundwater on the margins of historic lakes. A second group of fashions proposed that the sandstones started as basaltic ash and have been remodeled by means of the addition of volcanic or atmospheric sulfuric acid.

The authors of the brand new examine put forth a 3rd risk, that the 2 formations might come from the identical supply materials, or a minimum of a really related one. They proposed that the Burns/Grasberg precursor was deposited onto Meridiani Planum as particles of dust or falling ash from close by volcanic eruptions.

These supplies solidified, have been weathered to the scale of sand grains, and have been blown by the wind to their present location. As soon as settled, the sand dunes skilled periodic flows of groundwater, which enriched the higher layers in magnesium and sulfate. Water stream additionally cemented the sediments to kind the sandstones noticed by Alternative.

The examine’s authors constructed a mass steadiness mannequin simulating this state of affairs, and utilizing information collected by Alternative’s Alpha Particle X-ray Spectrometer, they decided that the brand new speculation higher matches Alternative’s observations than different beforehand proposed mechanisms do.

The findings may shift how scientists take into consideration the environmental conditions on early Mars and rework interpretations of the origin of sulfate-rich deposits discovered elsewhere on the planet.

This story is republished courtesy of Eos, hosted by the American Geophysical Union. Learn the unique story here.