Carbon isotopes in xenoliths from the Hualalai Volcano, Hawaii, and the generation of isotopic variability

Journal Article · Sun Dec 31 23:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(90)90209-4· OSTI ID:6692265

Pineau, F ^[1]; Mathez, E A ^[2]

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1. Univ. de Paris (France)
2. American Museum of Natural History, New York (USA)

The isotopic composition of carbon has been determined in a suite of xenoliths from lava of the 1800-1801 Kaupulehu eruption of Hualalai Volcano, Hawaii. Several lithologies are represented in the suite, including websterite, dunite, wehrlite, pyroxenite, and gabbro. In addition, there are composite xenoliths in which contacts between lithologies are preserved. Most of the xenoliths represent deformed cumulates. The contact relations in the composite samples indicate that the lithologies originated from the same source region, which, based on pressures determined from fluid inclusions, is estimated to be at a depth of {approx}20 km, or near the crust-mantle boundary. The observations and isotopic results demonstrate that isotopic variability can be generated by multistage fractionation processes such as degassing of CO{sub 2} from magma and precipitation of CO{sub 2}-rich fluids to form graphitic compounds. Such processes operated over regions the scales of which were determined by style and intensity of deformation and by lithology.

• OSTI ID: 6692265
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 54:1; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
DEGASSING
FEDERAL REGION IX
FRACTIONATION
GEOCHEMISTRY
HAWAII
IGNEOUS ROCKS
INCLUSIONS
ISOTOPE RATIO
ISOTOPES
LAVA
LITHOLOGY
MINERALOGY
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
PETROGENESIS
ROCKS
SEPARATION PROCESSES
USA
VARIATIONS
VOLCANIC ROCKS
VOLCANOES