Determination of methane stability in the upper mantle and lower crust. Final report, July 1, 1989-June 30, 1990
Technical Report
·
OSTI ID:7190545
In Part A of the report the authors examine the variability in mantle oxygen fugacity f(sub O2) from the Earth's suboceanic upper mantle. The samples they have examined are abyssal spinel peridotites. They chose to study abyssal spinel peridotites as probes of the upper mantle because a sufficient number of samples were available that had a broad global distribution. These provide important constraints on fluid speciation in the system C-O-H, the approximate bulk composition of dominant volatile species in the Earth's upper mantle. Part B of the report presents an analysis of available analytical data on volatiles trapped in quenched MORB glasses from three major oceanic rift systems. The results show that on average, the Earth's suboceanic mantle is more reduced than the subcontinental mantle and that both upper mantle regimes are too oxidized to be in equilibrium with graphite. The results also indicate that conditions favorable to CH4 being an important component of the volatile phase in the upper mantle may be satisfied in the vicinity of mantle plumes (i.e. hot spots). Assuming that the physical and chemical characteristics of mantle plumes are similar beneath the continents, the authors propose that an attractive subject for further research would be to investigate continental supracrustal sedimentary rocks, particularly in regions of continental extension where the manifestation of a subcontinental mantle plume are obvious.
- Research Organization:
- Northwestern Univ., Evanston, IL (United States). Dept. of Geological Sciences
- OSTI ID:
- 7190545
- Report Number(s):
- PB-93-100931/XAB; CNN: GRI-5087-260-1569
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxygen thermobarometry of abyssal spinel peridotites: The redox state and C-O-H volatile composition of the Earth's sub-oceanic upper mantle
World-wide occurrence of HFSE-depleted mantle
Tectonic denudation of upper mantle along passive margins: a model based on drilling (ODP Leg 103) and diving (Galinaute cruise) results, western Galicia Margin, Spain
Journal Article
·
Fri Nov 30 23:00:00 EST 1990
· American Journal of Science; (USA)
·
OSTI ID:5542635
World-wide occurrence of HFSE-depleted mantle
Journal Article
·
Mon Aug 01 00:00:00 EDT 1988
· Geochimica et Cosmochimica Acta; (USA)
·
OSTI ID:7164431
Tectonic denudation of upper mantle along passive margins: a model based on drilling (ODP Leg 103) and diving (Galinaute cruise) results, western Galicia Margin, Spain
Conference
·
Fri May 01 00:00:00 EDT 1987
· AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)
·
OSTI ID:6206338
Related Subjects
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
033000* -- Natural Gas-- Properties & Composition
ALKANES
ANTARCTIC OCEAN
ATLANTIC OCEAN
CARBON
CHEMICAL REACTIONS
CHEMISTRY
EARTH CRUST
EARTH MANTLE
ELEMENTAL MINERALS
ELEMENTS
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GRAPHITE
HOT SPOTS
HYDROCARBONS
IGNEOUS ROCKS
INDIAN OCEAN
METHANE
MID-ATLANTIC RIDGE
MINERALS
NONMETALS
OCEANIC CRUST
ORGANIC COMPOUNDS
OXIDATION
OXIDE MINERALS
OXYGEN
PARTIAL PRESSURE
PERIDOTITES
PLUMES
PLUTONIC ROCKS
RIFT ZONES
ROCKS
SEAS
SPINELS
STABILITY
SURFACE WATERS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
033000* -- Natural Gas-- Properties & Composition
ALKANES
ANTARCTIC OCEAN
ATLANTIC OCEAN
CARBON
CHEMICAL REACTIONS
CHEMISTRY
EARTH CRUST
EARTH MANTLE
ELEMENTAL MINERALS
ELEMENTS
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GRAPHITE
HOT SPOTS
HYDROCARBONS
IGNEOUS ROCKS
INDIAN OCEAN
METHANE
MID-ATLANTIC RIDGE
MINERALS
NONMETALS
OCEANIC CRUST
ORGANIC COMPOUNDS
OXIDATION
OXIDE MINERALS
OXYGEN
PARTIAL PRESSURE
PERIDOTITES
PLUMES
PLUTONIC ROCKS
RIFT ZONES
ROCKS
SEAS
SPINELS
STABILITY
SURFACE WATERS