Formation of H 2 , CH 4 and N-species during low-temperature experimental alteration of ultramafic rocks

Økland, I.; Huang, Shanshan; Thorseth, Ingunn H.; Pedersen, R. B.

doi:10.1016/j.chemgeo.2014.08.003

Cited by 30 publications

(50 citation statements)

References 98 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the results disagree with other recent reports, where the CH 4 produced during experimental reaction of olivine with aqueous solutions has been interpreted to be predominantly derived from abiotic reduction of dissolved inorganic carbon (22)(23)(24)(25). For example, Oze and coworkers (24, 25) investigated formation of CH 4 in a series of laboratory experiments in which olivine was reacted with aqueous solutions at 200°C.…”

Section: Discussioncontrasting

confidence: 55%

“…These experiments were performed using methods very similar to those of this study, except that the reaction vessel was periodically rotated during heating. After heating for [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] (Table 1). However, isotopic labeling indicated that the CH 4 in our experiments was not derived from reduction of dissolved inorganic carbon but instead, was derived entirely from background sources (i.e., composed of 99 mol % 12 CH 4 ).…”

Section: Discussionmentioning

confidence: 99%

“…Experimental studies performed at high temperatures (300°C and above) have shown that there exist strong kinetic barriers to abiotic CH 4 synthesis unless certain catalytic minerals, such as NiFe alloys, are present (16)(17)(18)(19)(20)(21). Conversely, several recent studies have reported abiotic synthesis of CH 4 during reaction of olivine with aqueous solutions at much lower temperatures (25°C to 200°C) (22)(23)(24)(25), although the kinetic barriers might be expected to preclude abiotic CH 4 synthesis at these conditions. The process of serpentinization can be summarized by the general reaction…”

mentioning

confidence: 95%

“…Although these studies provided substantial evidence for kinetic inhibition to abiotic CH 4 synthesis at elevated temperatures, several other studies in recent years have reported abiotic production during experimental alteration of olivine at much lower temperatures of 25°C to 200°C (22)(23)(24)(25). In each of these experiments, olivine was heated with aqueous fluids, and production of micromolar concentrations of CH 4 was observed.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Abiotic methane formation during experimental serpentinization of olivine

McCollom

2016

Proc. Natl. Acad. Sci. U.S.A.

170

148

View full text Add to dashboard Cite

Fluids circulating through actively serpentinizing systems are often highly enriched in methane (CH 4 ). In many cases, the CH 4 in these fluids is thought to derive from abiotic reduction of inorganic carbon, but the conditions under which this process can occur in natural systems remain unclear. In recent years, several studies have reported abiotic formation of CH 4 during experimental serpentinization of olivine at temperatures at or below 200°C. However, these results seem to contradict studies conducted at higher temperatures (300°C to 400°C), where substantial kinetic barriers to CH 4 synthesis have been observed. Here, the potential for abiotic formation of CH 4 from dissolved inorganic carbon during olivine serpentinization is reevaluated in a series of laboratory experiments conducted at 200°C to 320°C. A 13 C-labeled inorganic carbon source was used to unambiguously determine the origin of CH 4 generated in the experiments. Consistent with previous high-temperature studies, the results indicate that abiotic formation of CH 4 from reduction of dissolved inorganic carbon during the experiments is extremely limited, with nearly all of the observed CH 4 derived from background sources. The results indicate that the potential for abiotic synthesis of CH 4 in low-temperature serpentinizing environments may be much more limited than some recent studies have suggested. However, more extensive production of CH 4 was observed in one experiment performed under conditions that allowed an H 2 -rich vapor phase to form, suggesting that shallow serpentinization environments where a separate gas phase is present may be more favorable for abiotic synthesis of CH 4 .serpentinization | abiotic methane | hydrothermal systems

show abstract

Section: Discussioncontrasting

confidence: 55%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 95%

mentioning

confidence: 99%

See 2 more Smart Citations

Abiotic methane formation during experimental serpentinization of olivine

McCollom

2016

Proc. Natl. Acad. Sci. U.S.A.

170

148

View full text Add to dashboard Cite

show abstract

“…Investigations of naturally occurring abiogenic CH 4 indicate that abiotic hydrocarbon synthesis can potentially take place at temperatures as low as ∼120°C (46). However, there are contrasting experimental results concerning the formation and synthesis kinetics of CH 4 production at (very) low temperatures (47)(48)(49). In hydrothermal experiments, awaruite has been identified as a possible CH 4 production catalyst (50).…”

Section: ) Indicate Thatmentioning

confidence: 99%

Subduction zone forearc serpentinites as incubators for deep microbial life

Plümper

Geisler

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Serpentinization-fueled systems in the cool, hydrated forearc mantle of subduction zones may provide an environment that supports deep chemolithoautotrophic life. Here, we examine serpentinite clasts expelled from mud volcanoes above the Izu-BoninMariana subduction zone forearc (Pacific Ocean) that contain complex organic matter and nanosized Ni-Fe alloys. Using time-of-flight secondary ion mass spectrometry and Raman spectroscopy, we determined that the organic matter consists of a mixture of aliphatic and aromatic compounds and functional groups such as amides. Although an abiotic or subduction slab-derived fluid origin cannot be excluded, the similarities between the molecular signatures identified in the clasts and those of bacteria-derived biopolymers from other serpentinizing systems hint at the possibility of deep microbial life within the forearc. To test this hypothesis, we coupled the currently known temperature limit for life, 122°C, with a heat conduction model that predicts a potential depth limit for life within the forearc at ∼10,000 m below the seafloor. This is deeper than the 122°C isotherm in known oceanic serpentinizing regions and an order of magnitude deeper than the downhole temperature at the serpentinized Atlantis Massif oceanic core complex, MidAtlantic Ridge. We suggest that the organic-rich serpentinites may be indicators for microbial life deep within or below the mud volcano. Thus, the hydrated forearc mantle may represent one of Earth's largest hidden microbial ecosystems. These types of protected ecosystems may have allowed the deep biosphere to thrive, despite violent phases during Earth's history such as the late heavy bombardment and global mass extinctions.deep biosphere | serpentinization | subduction zone | forearc

show abstract

An Overlooked Natural Hydrogen Evolution Pathway: Ni²⁺ Boosting H₂O Reduction by Fe(OH)₂ Oxidation during Low‐Temperature Serpentinization

Song

Han

et al. 2021

Angewandte Chemie

View full text Add to dashboard Cite

Natural hydrogen (H 2 ) has gained considerable attentions as a renewable energy resource to mitigate the globally increasing environmental concerns. Low-temperature serpentinization (< 200 8C) as a typical water-rock reaction is a major source of the natural H 2 . However, the reaction mechanism and the controlling step to product H 2 remained unclear, which hinders the further utilization of natural H 2 . Herein, we demonstrated that the H 2 production rate could be determined by the Fe(OH) 2 oxidation during low-temperature serpentinization. Moreover, the co-existence of Ni 2+ could largely enhance the H 2 production kinetics. With the addition of only 1 % Ni 2+ , the H 2 production rate was remarkably enhanced by about two orders of magnitude at 90 8C. D 2 O isotopic experiment and theoretical calculations revealed that the enhanced H 2 production kinetics could be attributed to the catalytic role of Ni 2+ to promote the reduction of H 2 O.

show abstract

Formation of H 2 , CH 4 and N-species during low-temperature experimental alteration of ultramafic rocks

Cited by 30 publications

References 98 publications

Abiotic methane formation during experimental serpentinization of olivine

Abiotic methane formation during experimental serpentinization of olivine

Subduction zone forearc serpentinites as incubators for deep microbial life

An Overlooked Natural Hydrogen Evolution Pathway: Ni²⁺ Boosting H₂O Reduction by Fe(OH)₂ Oxidation during Low‐Temperature Serpentinization

Contact Info

Product

Resources

About

Formation of H 2 , CH 4 and N-species during low-temperature experimental alteration of ultramafic rocks

Cited by 30 publications

References 98 publications

Abiotic methane formation during experimental serpentinization of olivine

Abiotic methane formation during experimental serpentinization of olivine

Subduction zone forearc serpentinites as incubators for deep microbial life

An Overlooked Natural Hydrogen Evolution Pathway: Ni2+ Boosting H2O Reduction by Fe(OH)2 Oxidation during Low‐Temperature Serpentinization

Contact Info

Product

Resources

About

An Overlooked Natural Hydrogen Evolution Pathway: Ni²⁺ Boosting H₂O Reduction by Fe(OH)₂ Oxidation during Low‐Temperature Serpentinization