Isotopic signatures of abiotic organic synthesis under geologic conditions

2006 ◽  
Vol 70 (18) ◽  
pp. A0407 ◽  
Author(s):  
T.M. McCollom ◽  
J.S. Seewald ◽  
B. Sherwood Lollar ◽  
G. Lacrampe-Couloume
Keyword(s):  
Organic Synthesis ◽  
Isotopic Signatures ◽  
Abiotic Organic Synthesis

Hydrothermal exploration and astrobiology: oases for life in distant oceans?

2004 ◽  
Vol 3 (2) ◽  
pp. 81-95 ◽  
Author(s):  
Christopher R. German
Keyword(s):  
High Temperature ◽  
Organic Synthesis ◽  
Autonomous Underwater Vehicle ◽  
De Novo ◽  
The Arctic ◽  
Ocean Ridges ◽  
Abiotic Organic Synthesis ◽  
Preliminary Identification ◽  
Slow Spreading ◽  
Hydrothermal Fields

High-temperature submarine hydrothermal fields on Earth's mid-ocean ridges play host to exotic ecosystems with fauna previously unknown to science. Because these systems draw significant energy from chemosynthesis rather than photosynthesis, it has been postulated that the study of such systems could have relevance to the origins of life and, hence, astrobiology. A major flaw to that argument, however, is that modern basalt-hosted submarine vents are too oxidizing and lack the abundant free hydrogen required to drive abiotic organic synthesis and/or the energy yielding reactions that the most primitive anaerobic thermophiles isolated from submarine vent-sites apparently require. Here, however, the progress over the past decade in which systematic search strategies have been used to identify previously overlooked venting on the slow-spreading Mid-Atlantic Ridge and the ultra-slow spreading Arctic and SW Indian Ridges is described. Preliminary identification of fault-controlled venting in a number of these sites has led to the discovery of at least two high-temperature hydrothermal fields hosted in ultramafic rocks which emit complex organic molecules in their greater than 360 °C vent-fluids. Whether these concentrations represent de novo organic synthesis within the hydrothermal cell remains open to debate but it is probable that many more such sites exist throughout the Atlantic, Arctic and SW Indian Oceans. One particularly intriguing example is the Gakkel Ridge, which crosses the floor of the Arctic Ocean. On-going collaborations between oceanographers and astrobiologists are actively seeking to develop a new class of free-swimming autonomous underwater vehicle, equipped with appropriate chemical sensors, to conduct long-range missions that will seek out, locate and investigate new sites of hydrothermal venting at the bottom of this, and other, ice-covered oceans.

scholarly journals Pathways for abiotic organic synthesis at submarine hydrothermal fields

2015 ◽  
Vol 112 (25) ◽  
pp. 7668-7672 ◽  
Author(s):  
Jill M. McDermott ◽  
Jeffrey S. Seewald ◽  
Christopher R. German ◽  
Sean P. Sylva
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Deep Sea ◽  
Hot Springs ◽  
Hydrothermal Systems ◽  
Deep Biosphere ◽  
Shallow Subsurface ◽  
Microbial Life ◽  
Abiotic Organic Synthesis ◽  
Life On Earth

Arguments for an abiotic origin of low-molecular weight organic compounds in deep-sea hot springs are compelling owing to implications for the sustenance of deep biosphere microbial communities and their potential role in the origin of life. Theory predicts that warm H2-rich fluids, like those emanating from serpentinizing hydrothermal systems, create a favorable thermodynamic drive for the abiotic generation of organic compounds from inorganic precursors. Here, we constrain two distinct reaction pathways for abiotic organic synthesis in the natural environment at the Von Damm hydrothermal field and delineate spatially where inorganic carbon is converted into bioavailable reduced carbon. We reveal that carbon transformation reactions in a single system can progress over hours, days, and up to thousands of years. Previous studies have suggested that CH4 and higher hydrocarbons in ultramafic hydrothermal systems were dependent on H2 generation during active serpentinization. Rather, our results indicate that CH4 found in vent fluids is formed in H2-rich fluid inclusions, and higher n-alkanes may likely be derived from the same source. This finding implies that, in contrast with current paradigms, these compounds may form independently of actively circulating serpentinizing fluids in ultramafic-influenced systems. Conversely, widespread production of formate by ΣCO2 reduction at Von Damm occurs rapidly during shallow subsurface mixing of the same fluids, which may support anaerobic methanogenesis. Our finding of abiogenic formate in deep-sea hot springs has significant implications for microbial life strategies in the present-day deep biosphere as well as early life on Earth and beyond.

Abiotic Organic Synthesis in Space

1981 ◽  
pp. 65-71
Author(s):  
M. R. Bloch ◽  
H. L. Wirth
Keyword(s):  
Organic Synthesis ◽  
Abiotic Organic Synthesis

Abiotic organic synthesis in space

1980 ◽  
Vol 67 (11) ◽  
pp. 562-564 ◽  
Author(s):  
M. R. Bloch ◽  
H. L. Wirth
Keyword(s):  
Organic Synthesis ◽  
Abiotic Organic Synthesis
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