![\"Lim](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/05\/image_14785-Hapcheon-Crater.jpg\")
<\/p>\nResearchers have discovered stromatolites \u2014 layered structures formed by microbial communities \u2014 inside a 42,000-year-old asteroid crater in South Korea, suggesting ancient post-impact lakes may have acted as \u2018oxygen oases\u2019 for early life.<\/p>\n
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Lim et al. demonstrate that stromatolites \u2014 the oldest fossil evidence of oxygen-producing microbial life on early Earth \u2014 could have developed within impact craters, based on a detailed investigation of stromatolites and lake sediments in the Hapcheon impact crater, South Korea. Image credit: Lim et al., doi: 10.1038\/s43247-026-03206-7.<\/p>\n
\u201cStromatolite \u2014 laminated sedimentary structures accretionary away from appoint or limited surface \u2014 is considered the oldest evidence of life on Earth, dating back to approximately 3.5\u2009billion years in the early Archean,\u201d said lead author Dr. Jaesoo Lim and colleagues from the Korea Institute of Geoscience and Mineral Resources.<\/p>\n
\u201cTheir laminated organo-sedimentary structures form through the trapping and binding of sediment grains by microbial activity or the precipitation of minerals driven by microbial metabolic processes.\u201d<\/p>\n
The researchers discovered multiple stromatolites \u2014 each measuring 10-20 cm in diameter \u2014 in the northwestern part of the Hapcheon crater in South Korea.<\/p>\n
\u201cGeochemical analyses of the stromatolites revealed several key features, including signatures of both extraterrestrial material and surrounding bedrock, as well as evidence of alteration by high-temperature water,\u201d they said.<\/p>\n
\u201cThe inner layers show stronger hydrothermal signals, suggesting they formed during an earlier, hotter phase.\u201d<\/p>\n
\u201cTogether, these findings support the interpretation that the stromatolites developed in a post-impact hydrothermal lake that gradually cooled over time.\u201d<\/p>\n
The results show that the Hapcheon impact event occurred approximately 42,300 years ago.<\/p>\n
\u201cThe findings offer new insight into the Great Oxidation Event, a period around 2.4 billion years ago when oxygen levels in Earth\u2019s atmosphere rose dramatically,\u201d the scientists said.<\/p>\n
\u201cImpact-generated hydrothermal lakes could have served as localized habitats where oxygen-producing microbes could thrive.\u201d<\/p>\n
\u201cThese environments may have formed what the team describes as oxygen oases.\u201d<\/p>\n
The study also raises the possibility that similar environments may have existed on early Mars.<\/p>\n
Because Mars is believed to have hosted water-filled impact craters in its early history, crater environments could be promising targets in the search for evidences of past life.<\/p>\n
\u201cThis is the first comprehensive evidence suggesting that stromatolites could form in hydrothermal lakes created by asteroid impacts,\u201d Dr. Lim said.<\/p>\n
\u201cSuch environments may have provided favorable conditions for early microbial ecosystems.\u201d<\/p>\n