So even though old records of life may have been erased in the brine patches, the chemical conditions brought about by the influx of salty water may have enabled more life to spring up in its place, the scientists said. The process of chemical transformation in sediments is called diagenesis, and it could have created new life beneath Mars even as it erased some of the evidence of the old life on its surface, according to the study authors. The rover completed its analysis by drilling into the layers of the Martian rock before using its chemistry and mineralogy instrument, known as CheMin, to investigate the samples. "But later brines broke down these clay minerals in some places - essentially resetting the rock record." "We used to think that once these layers of clay minerals formed at the bottom of the lake in Gale Crater, they stayed that way, preserving the moment in time they formed for billions of years," study lead author Tom Bristow, a researcher at NASA's Ames Research Center in Mountain View, California, said in a statement. The team believes the culprit behind this geological disappearing act is brine: supersalty water that leaked into the mineral-rich clay layers and destabilized them, flushing them away and wiping patches of both the geological - and possibly even the biological - record clean.
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