·
·
Tech & Science
Researchers discovered ancient stromatolites in South Korea's Hapcheon crater, indicating asteroid impacts may have fostered early oxygen-producing life on Earth.
Scientists from the Korea Institute of Geoscience and Mineral Resources (KIGAM) have identified stromatolites within the Hapcheon impact crater, marking the first confirmed occurrence of these ancient microbial structures in the only verified asteroid crater on the Korean Peninsula.
Stromatolites, layered rock formations created by ancient microbial communities, are among the earliest known evidence of life on Earth, often linked to cyanobacteria capable of oxygenic photosynthesis. The discovered stromatolites, measuring between 10 and 20 centimeters, were located in the northwestern part of the crater.
The research suggests these stromatolites formed in a hydrothermal lake that developed following a significant asteroid impact. The heat from molten rock generated by the collision likely maintained warm, mineral-rich waters for extended periods, creating a favorable environment for microbial life to thrive.
Geochemical analyses revealed signatures associated with both extraterrestrial material and the local bedrock, alongside evidence of alteration by high-temperature water. The innermost stromatolite layers exhibited stronger hydrothermal characteristics, indicating formation during an early, hotter phase of the crater lake.
This discovery offers new insights into the Great Oxidation Event (GOE) approximately 2.4 billion years ago, when atmospheric oxygen levels increased substantially. The study proposes that hydrothermal lakes within asteroid craters may have acted as isolated "oxygen oases," supporting oxygen-producing microbes before oxygen became widespread globally.
Beyond Earth, the findings may inform the search for ancient life on Mars, where early impact craters likely contained water. Similar crater environments on Mars could potentially harbor evidence of past microbial ecosystems.
This research expands upon earlier work published in 2021 in Gondwana Research, which first confirmed the Hapcheon crater's existence. The current study adds biological evidence through stromatolite discovery and associated geochemical data.
Dr. Jaesoo Lim, lead author, stated, "This is the first comprehensive evidence suggesting that stromatolites could form in hydrothermal lakes created by asteroid impacts. Such environments may have provided favorable conditions for early microbial ecosystems."
