- journal_title：Geology
- Contributor：Larissa F. Dobrzhinetskaya ; Elizabeth A. Eide ; Rune B. Larsen ; Brian A. Sturt ; Reidar G. Trønnes ; David C. Smith ; Wayne R. Taylor ; Tatjana V. Posukhova
- Publisher：Geological Society of America
- Date：1995-
- Format：text/html
- Language：en
- Identifier：10.1130/0091-7613(1995)023<0597:MIHGMR>2.3.CO;2
- journal_abbrev：Geology
- issn：0091-7613
- volume：23
- issue：7
- firstpage：597
Three grains of microdiamond were recovered from high-grade gneiss exposed in the Western Gneiss region, Norway. Identification and characterization of the diamond grains by Raman and infrared spectroscopy indicate the presence of substitutional impurities of H and N. Primary fluid inclusions in garnet and quartz in the diamond-bearing rock demonstrate the evolution of metamorphic volatile fluids from reduced N2-CO2 compositions during the peak phase of metamorphism, to N2-CH4 ± H2O–bearing compositions during retrograde metamorphism. Compatible geologic, petrologic, and fluid composition data imply a metamorphic origin for the microdiamonds; if so, the metamorphic and fluid conditions recorded by the microdiamonds and gneissic host may be applicable to microdiamond investigations in other high-pressure, regionally metamorphosed orogens.