Thermodynamic modelling of C–O–H fluids

Huizenga, Jan Marten

doi:10.1016/s0024-4937(00)00040-2

Cited by 87 publications

(56 citation statements)

References 45 publications

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“…This is in agreement with the expected speciation in a graphite-bearing system C-H-O system, because at T < 500°C, the graphite stability field essentially coincides with the CO 2 -H 2 O and CH 4 -H 2 O binaries in a C-O-H diagram ( Fig. 10B; Holloway, 1984;Huizenga, 2001). We follow Giggenbach (1987) in that the Fig.…”

Section: Evolution Of the Redox State And The Composition Of The Carbsupporting

confidence: 86%

“…In a C-O-H system, the main equilibria governing speciations of C-O-H species can then be written as (Ohmoto and Kerrick, 1977;Huizenga, 2001)…”

Section: Evolution Of the Redox State And The Composition Of The Carbmentioning

confidence: 99%

“…5D. (B) Explanatory ternary C-O-H diagram showing the graphite saturation boundary at a randomly chosen P and T (afterHuizenga, 2001). A graphite undersaturated fluid with arbitrary composition (block dot) could move into the graphite field by loss of H 2 O (indicated by arrow).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Metamorphic fluid flow in the northeastern part of the 3.8–3.7Ga Isua Greenstone Belt (SW Greenland): A re-evalution of fluid inclusion evidence for early Archean seafloor-hydrothermal systems

Heijlen

Appel

Frezzotti

et al. 2006

Geochimica et Cosmochimica Acta

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Section: Evolution Of the Redox State And The Composition Of The Carbsupporting

confidence: 86%

“…In a C-O-H system, the main equilibria governing speciations of C-O-H species can then be written as (Ohmoto and Kerrick, 1977;Huizenga, 2001)…”

Section: Evolution Of the Redox State And The Composition Of The Carbmentioning

confidence: 99%

See 1 more Smart Citation

Metamorphic fluid flow in the northeastern part of the 3.8–3.7Ga Isua Greenstone Belt (SW Greenland): A re-evalution of fluid inclusion evidence for early Archean seafloor-hydrothermal systems

Heijlen

Appel

Frezzotti

et al. 2006

Geochimica et Cosmochimica Acta

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“…Such a model for melts, especially carbonatitic melts at these pressures and temperatures, is lacking. There are models available for C-H-O fluids (Huizenga 2001(Huizenga , 2005Duan 2009, 2010), however, which provide a starting point for assessing the behavior of fluids. As discussed previously (e.g., Stachel and Harris 2009), C-H-O fluids may be responsible for diamond formation in harzburgites, which have higher hydrous solidus temperatures relative to lherzolites or eclogites.…”

Section: Evolution Of Cho Fluidsmentioning

confidence: 99%

The buffering capacity of lithospheric mantle: implications for diamond formation

Luth

Stachel

2014

Contrib Mineral Petrol

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50 ppm or less O 2 is required to shift a depleted mantle peridotite the observed four log units of fO 2 . Coupled with the observed distribution of samples at values of fO 2 intermediate between the most reduced (metal-saturated) and most oxidized (carbonate-saturated) possible values for diamond stability, these results demonstrate that peridotites are very poor sinks or sources of O 2 for possible redox reactions to form diamond. A corollary of the poor redox buffering capacity of cratonic peridotites is that they can be employed as faithful indicators of the redox state of the last metasomatic fluid that passed through them. We propose that diamond formation from CHO fluids is a predictable consequence either of isobaric cooling or of combined cooling and decompression of the fluid as it migrates upward in the lithosphere. This establishes a petrological basis for the observed close connection between subcalcic garnet and diamond: based on high solidus temperatures of harzburgite and dunite effectively precluding dilution of CHO fluids through incipient melts, such highly depleted cratonic peridotites are the preferred locus of diamond formation. Due to a rapid increase in solidus temperature with increasing CH 4 content of the fluid, diamond formation related to reduced CHO fluids may also occur in some cratonic lherzolites.

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“…The real trapping temperatures are expected to be higher if a pressure correction of the homogenization temperature is applied. Huizenga (2001) shows in a thermodynamic evaluation of the C-O-H system that CO 2 -poor fluids are stable only at temperatures below 400 to 450°C, depending on the fO 2 and whether graphite was present. Calculation of isochores, based on the composition of the fluid inclusions has not been attempted for the following reasons: (1) the lack of microthermometric data of the CH 4 -rich/ H 2 O-poor fluid inclusions, and (2) the high probability of density modification during uplift, which leads to considerable pressure underestimations as shown in many studies of fluid inclusions in high pressure rocks (see Philippot and Selverstone, 1992;Selverstone et al, 1992;Sterner and Bodnar, 1989).…”

Section: P-t Constraints On the Entrapment Of The Fluid Inclusionsmentioning

confidence: 99%

Methane (CH4)-bearing fluid inclusions in the Myanmar jadeitite

et al. 2005

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A combined hydrogen-carbon-isotope and microthermometric study has been carried out on CH 4 -bearing fluid inclusions in high-pressure jadeitites from the famous jadeite tract Myanmar. Two types of fluid inclusions were found in jadeites, large H 2 O-rich and CH 4 -poor inclusions and small H 2 O-poor and CH 4 -rich inclusions, thus indicating a possible entrapment of CH 4 -H 2 O fluids under unmixing conditions. Microthermometric results yield lower temperature limits for the entrapment of these fluid inclusions of ca. 300 to 400°C. The bulk composition of the fluid inclusions is mostly H 2 O (87 to 94 mol.% H 2 O) and the isotopic composition of methane and water in the inclusions is characterized by δ 13 C(CH 4 ) values ranging from -30.1 to -25.5‰, and δD(H 2 O) values ranging from -56.3 to -49.8‰. The stable isotope data would be indicative of an abiogenic mechanism of CH 4 formation; the occurrence of the jadeite veins in this paleo-subduction zone thus most likely point to the formation of these CH 4 -bearing fluid inclusions by abiogenic thermal maturation of subducted organic carbon. These data not only provide evidence for cycling of organic carbon in paleo-subduction zones but also show that CH 4 not only occurs as shallow CH 4 -rich plumes in accretionary prisms of recent subduction zones but also occurs in deeper portions of at least the upper 20 km of paleo-subduction zones.

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Thermodynamic modelling of C–O–H fluids

Cited by 87 publications

References 45 publications

Metamorphic fluid flow in the northeastern part of the 3.8–3.7Ga Isua Greenstone Belt (SW Greenland): A re-evalution of fluid inclusion evidence for early Archean seafloor-hydrothermal systems

Metamorphic fluid flow in the northeastern part of the 3.8–3.7Ga Isua Greenstone Belt (SW Greenland): A re-evalution of fluid inclusion evidence for early Archean seafloor-hydrothermal systems

The buffering capacity of lithospheric mantle: implications for diamond formation

Methane (CH4)-bearing fluid inclusions in the Myanmar jadeitite

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