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| Mineral aggregates recovered from dissociated hydrate are relatively pure dolomite. (a) Light microscopy of single-grained dolomites showing dark inclusions (UTCW J25R, 53.9 mbsf, Mg/Ca = 0.91). (b) Single and paired “dumbbell” grains, showing layering in the internal dark portions (UTCW J22R, 28.7 mbsf, Mg:Ca = 0.92. (c) Shallow dumbbell grain (UTCW J21R, 12.2 mbsf, Mg:Ca = 0.74). Shallow grains (<20mbsf) show rough surfaces comprised of ~5 μm dolomite rhombs and low Mg/Ca ratios. (d) Deeper grains consist of smooth intergrown dolomite plates ~15 μm. The overall size of the deep grains ranges from 20 μm to > 150 μm and Mg:Ca ratios approaching 1 (UTCW J25R, 57 mbsf, Mg:Ca = 0.97). (e) Broken chain structure (UTCW J25R, 67.4 mbsf) shows smooth intergrowth of dolomite rhombs on the outer surface. (f) Close-up of previous grain showing concentric porous rings on the inside of the broken surface, possibly consisting of organic matter or residual fluid. |
British and Japanese scientists, who were studying the so-called " flammable ice " in the Sea of Japan, made a surprising discovery: There is life in the microscopic bubbles of frozen combustible material, researchers has found bacterial communities within microscopic spheroidal aggregates of dolomite, oil and water found in sheets of frozen methane and ice, known as ‘flammable ice,’ in Joetsu Basin, Japan Sea.
“We’re melting hydrate to study methane gas when we noticed an unusual powder consisting of microscopic spheroids with mysterious dark cores,” said Dr. Glen T. Snyder, a researcher at the Meiji University Global Front, Japan.
“In combination with the other evidence collected by my colleagues, my results showed that even under near-freezing temperatures, at extremely high pressures, with only heavy oil and saltwater for food-sources, life was flourishing and leaving its mark,” said Dr. Stephen Bowden, a researcher at the University of Aberdeen.
“But what we never expected to find was microbes continuing to grow and produce these spheroids, all of the time while isolated in tiny cold dark pockets of saltwater and oil,” Dr. Snyder continued.
“It certainly gives a positive spin to cold dark places, and opens up a tantalising clue as to the existence of life on other planets.” said Bowden.
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| (a) Flammable ice, as collected from the seabed. (b) Detail of one of the test pieces. (c) Methane hydrate after heating and centrifuged for analysis, showing oil on top and granules containing micro-habitats on the bottom. |
"Alien" Life on Earth
The tiny bubbles are scattered inside large hydrate plates, known as "flammable ice" - or methane hydrate - that are formed when ice retains methane in its molecular structure.There has been great interest in the exploration of this material as a fuel, with Japan and China leading this research.
Glen Snyder and colleagues from several Japanese and UK universities were melting hydrates to study methane gas when they noticed an unusual powder made up of microscopic spheroids with very peculiar dark nuclei.
Analytical techniques allowed to verify that the dark nuclei consist of oil that was being degraded in the microenvironments formed inside the bubbles of the methane hydrate.
"It is known that methane [present] in methane hydrate forms as microbes degrade organic matter on the seabed. But what we never expected to discover was that microbes would continue to grow and produce these spheroids during all the time they were isolated in small dark and cold bags of salt water and oil. That certainly changes everything about dark and cold places, and reveals a tantalizing clue about the existence of life on other planets," said Snyder.
"It certainly changes the way I think about things. As long as they have ice and a little heat, all those cold, frozen planets at the edge of the entire planetary system could host tiny microhabitats with microbes building their own 'death stars. 'and creating its tiny atmospheres and ecosystems, as we found out here," said Professor Stephen Bowden, a member of the team.
| Bibliography: Article: Evidence in the Japan Sea of microdolomite mineralization within gas hydrate microbiomes Authors: Glen T. Snyder, Ryo Matsumoto, Yohey Suzuki, Mariko Kouduka, Yoshihiro Kakizaki, Naizhong Zhang, Hitoshi Tomaru, Yuji Sano, Naoto Takahata, Kentaro Tanaka, Kentaro Tanaka Stephen A. Bowden, Takumi Imajo Magazine: Nature Scientific Reports Vol .: 10, Article number: 1876 DOI: 10.1038 / s41598-020-58723-y |
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Planet and Environment