This is important because it means these rocks were less likely to have been altered in a hydrothermal environment, where scalding hot water was temporarily released by melting ice caused by volcanism or a meteorite impact.
Instead, they appear to have been altered under modest temperatures and persistent heavy rainfall. The authors found distinct similarities between the chemical composition of these clay pebbles with similar clays found on Earth dating from periods in our planet’s history when the climate was much warmer and wetter.
False colour image of the dried up river delta in Jezero crater, which Perseverance is currently exploring.
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