Mantle wedge oxidation due to sediment-infiltrated deserpentinisation

Abstract The Earth's mantle is oxygen-breathing through the ¬sink of oxidised tectonic plates at convergent margins. Ocean floor serpentinisation increases the bulk oxidation state of iron relative to dry oceanic mantle and results in a variable intake of other redox-sensitive elements such as sulphur. The reversibility of seafloor oxidation in subduction zones during high-pressure dehydration of serpentinite (“deserpentinisation”) at subarc depths and the capacity of the resulting fluids to oxidise the mantle source of arc basalts are highly contested. Thermodynamic modelling, experiments, and metaperidotite study in exhumed high-pressure terrains result in differing estimates of the redox state of deserpentinisation fluids, ranging from low to highly oxidant. Here we show that although intrinsic deserpentinisation fluids are highly oxidant, the infiltration of small fractions of external fluids equilibrated with metasedimentary rocks strongly modulates their redox state and oxidation-reduction capacity explaining the observed discrepancies in their redox state. Infiltration of fluids equilibrated with graphite-bearing sediments reduces the oxidant, intrinsic deserpentinisation fluids to oxygen fugacities similar to those observed in most graphite-furnace experiments and natural metaperidotites. However, infiltration of CO2-bearing fluids equilibrated with modern GLOSS generates sulphate-rich, highly oxidising deserpentinisation fluids. We show that such GLOSS-infiltrated deserpentinisation fluids can effectively oxidise the mantle wedge of cold to hot subduction zones potentially accounting for the presumed oxidised nature of the source of arc basalts.

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Geochemical and Nd isotopic constraints for the origin of eclogite protoliths, northern Cordillera: implications for the Paleozoic tectonic evolution of the Yukon-Tanana terrane

Canadian Journal of Earth Sciences ◽

10.1139/e99-070 ◽

1999 ◽

Vol 36 (10) ◽

pp. 1697-1709 ◽

Cited By ~ 12

Author(s):

Robert A Creaser ◽

Jo-Anne S Goodwin-Bell ◽

Philippe Erdmer

Keyword(s):

High Pressure ◽

Subduction Zone ◽

Convergent Margins ◽

Metasedimentary Rocks ◽

High Pressure Metamorphism ◽

Distal Edge ◽

History Of ◽

Convergent Plate Margin ◽

Ocean Ridge ◽

Subduction Zone Magmatism

On the basis of trace-element data, basaltic protoliths for Paleozoic eclogites from the Yukon-Tanana terrane (YTT) have diverse origins. Eclogites from Stewart Lake and the Simpson Range have characteristics of basaltic protoliths generated by subduction-zone magmatism, are hosted by serpentinitic-gabbroic rocks, and record Mississippian high-pressure metamorphism and cooling. In contrast, eclogites from Faro, Ross River, and Last Peak show either within-plate geochemistry or mid-ocean ridge protolith geochemistry with a small subduction component, are hosted by continental metasedimentary rocks of the Nisutlin assemblage, and record Permian high-pressure metamorphism and cooling. We interpret these results to derive from the following tectonic events in the Paleozoic history of the YTT: (1) activity at a Devonian-Mississippian convergent plate margin at the distal edge of North America, with near-contemporaneous subduction-zone magmatism and high-pressure metamorphism; (2) Mississippian rifting of that margin to form the outboard YTT, the Slide Mountain marginal basin, and the Faro, Ross River, and Last Peak eclogite protoliths; and (3) west-dipping subduction of the Slide Mountain Ocean under the outboard YTT in Permian time, to produce the Faro, Ross River, and Last Peak eclogites and Permian arc magmatism throughout the YTT. The basaltic protoliths of the Paleozoic YTT eclogites bear close similarity to those produced in rifted convergent margins, such as the Miocene Japanese arc - back-arc system.

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Decoupling of inorganic and organic carbon during slab mantle devolatilisation

Nature Communications ◽

10.1038/s41467-022-27970-0 ◽

2022 ◽

Vol 13 (1) ◽

Author(s):

P. Bouilhol ◽

B. Debret ◽

E. C. Inglis ◽

M. Warembourg ◽

T. Grocolas ◽

...

Keyword(s):

High Pressure ◽

Organic Carbon ◽

Subduction Zones ◽

Inorganic Carbon ◽

Mantle Wedge ◽

Isotope Composition ◽

Sr Isotope ◽

Ultra High Pressure ◽

Isotope Analyses ◽

Inorganic And Organic

AbstractSerpentinites are an important sink for both inorganic and organic carbon, and their behavior during subduction is thought to play a fundamental role in the global cycling of carbon. Here we show that fluid-derived veins are preserved within the Zermatt-Saas ultra-high pressure serpentinites providing key evidence for carbonate mobility during serpentinite devolatilisation. We show through the O, C, and Sr isotope analyses of vein minerals and the host serpentinites that about 90% of the meta-serpentinite inorganic carbon is remobilized during slab devolatilisation. In contrast, graphite-like carbonaceous compounds remain trapped within the host rock as inclusions within metamorphic olivine while the bulk elemental and isotope composition of organic carbon remains relatively unchanged during the subduction process. This shows a decoupling behavior of carbon during serpentinite dehydration in subduction zones. This process will therefore facilitate the transfer of inorganic carbon to the mantle wedge and the preferential slab sequestration of organic carbon en route to the deep mantle.

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Massive carbon storage in convergent margins initiated by subduction of limestone

Nature Communications ◽

10.1038/s41467-021-24750-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Chunfei Chen ◽

Michael W. Förster ◽

Stephen F. Foley ◽

Yongsheng Liu

Keyword(s):

Carbon Storage ◽

Carbon Flux ◽

Subduction Zones ◽

Mantle Wedge ◽

Magma Ascent ◽

Convergent Margins ◽

Sedimentary Carbonate ◽

Carbon Reservoir ◽

High Pressure Reaction ◽

Earth’S Climate

AbstractRemobilization of sedimentary carbonate in subduction zones modulates arc volcanism emissions and thus Earth’s climate over geological timescales. Although limestones (or chalk) are thought to be the major carbon reservoir subducted to subarc depths, their fate is still unclear. Here we present high-pressure reaction experiments between impure limestone (7.4 wt.% clay) and dunite at 1.3–2.7 GPa to constrain the melting behaviour of subducted natural limestone in contact with peridotite. The results show that although clay impurities significantly depress the solidus of limestone, melting will not occur whilst limestones are still part of the subducting slab. Buoyancy calculations suggest that most of these limestones would form solid-state diapirs intruding into the mantle wedge, resulting in limited carbon flux to the deep mantle (< ~10 Mt C y−1). Less than 20% melting within the mantle wedge indicates that most limestones remain stable and are stored in subarc lithosphere, resulting in massive carbon storage in convergent margins considering their high carbon flux (~21.4 Mt C y−1). Assimilation and outgassing of these carbonates during arc magma ascent may dominate the carbon flux in volcanic arcs.

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Up the down escalator: the exhumation of (ultra)-high pressure terranes during on-going subduction

Solid Earth Discussions ◽

10.5194/sed-4-745-2012 ◽

2012 ◽

Vol 4 (1) ◽

pp. 745-781 ◽

Cited By ~ 5

Author(s):

C. J. Warren

Keyword(s):

High Pressure ◽

Subduction Zone ◽

Continental Crust ◽

Subduction Zones ◽

Crustal Material ◽

Time And Space ◽

Ultra High Pressure ◽

Tectonic Environment ◽

Tectonic Style ◽

Weak Material

Abstract. The exhumation of high and ultra-high pressure rocks is ubiquitous in Phanerozoic orogens created during continental collisions, and is common in many ocean-ocean and ocean-continent subduction zone environments. Three different tectonic environments have previously been reported, which exhume deeply buried material by different mechanisms and at different rates. However it is becoming increasingly clear that no single mechanism dominates in any particular tectonic environment, and the mechanism may change in time and space within the same subduction zone. In order for buoyant continental crust to subduct, it must remain attached to a stronger and denser substrate, but in order to exhume, it must detach (and therefore at least locally weaken) and be initially buoyant. Denser oceanic crust subducts more readily than more buoyant continental crust but exhumation must be assisted by entrainment within more buoyant and weak material such as serpentinite or driven by the exhumation of structurally lower continental crustal material. Weakening mechanisms responsible for the detachment of crust at depth include strain, hydration, melting, grain size reduction and the development of foliation. These may act locally or may act on the bulk of the subducted material. Metamorphic reactions, metastability and the composition of the subducted crust all affect buoyancy and overall strength. Subduction zones change in style both in time and space, and exhumation mechanisms change to reflect the tectonic style and overall force regime within the subduction zone. Exhumation events may be transient and occur only once in a particular subduction zone or orogen, or may be more continuous or occur multiple times.

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PULMONARY DAMAGE DUE TO HIGH PRESSURE OXYGEN BREATHING IN RATS

Australian Journal of Experimental Biology and Medical Science ◽

10.1038/icb.1962.7 ◽

1962 ◽

Vol 40 (1) ◽

pp. 51-56 ◽

Cited By ~ 29

Author(s):

Dana Jamieson ◽

HAS van den Brenk

Keyword(s):

High Pressure ◽

Oxygen Breathing ◽

Pressure Oxygen ◽

Pulmonary Damage ◽

High Pressure Oxygen

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High-pressure experimental verification of rutile-ilmenite oxybarometer: Implications for the redox state of the subduction zone

Science China Earth Sciences ◽

10.1007/s11430-016-9082-5 ◽

2017 ◽

Vol 60 (10) ◽

pp. 1817-1825 ◽

Cited By ~ 4

Author(s):

RenBiao Tao ◽

LiFei Zhang ◽

Vincenzo Stagno ◽

Xu Chu ◽

Xi Liu

Keyword(s):

High Pressure ◽

Subduction Zone ◽

Experimental Verification ◽

Redox State

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Effects of High Pressure Processing on the Quality of Vacuum Packed Fish Patties

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.644-650.4671 ◽

2014 ◽

Vol 644-650 ◽

pp. 4671-4676

Author(s):

Ying Chun Zhu ◽

Li Zhen Ma ◽

Yu Jing Tian ◽

Hua Yang ◽

Yao Hua Guo ◽

...

Keyword(s):

High Pressure ◽

Bacterial Growth ◽

Reduction Potential ◽

Meat Products ◽

High Pressure Processing ◽

Control Group ◽

Oxidation Reduction ◽

Preservation Method ◽

Oxidation Reduction Potential

The objective of this study was to evaluate the use of high pressure processing (HPP) as a preservation method of meat products. Vacuum-packaged fish patties were subjected to HPP (300 MPa for 30 min 15°C or 500 Mpa for 10 min at 15°C). Untreated samples represented the control group. The three groups were stored at 4°C for 0–5 weeks. Color parameters, pH, thiobarbituric (TBARS), bacterial growth, and Oxidation-Reduction Potential (ORP) were determined. The results revealed that the 500-MPa treatment inhibited bacterial growth and extended the shelf-life of fish patties to four weeks with insignificant effects on the physicochemical attributes.

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