Robert J. Bodnar

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Abundant graphite particles occur in amphibolite-grade quartzite of the Archean-Paleoproterozoic Wutai Metamorphic Complex in the Wutaishan area of North China. Petrographic thin section observations suggest that the graphite particles occur within and between quartzite clasts and are heterogeneous in origin. Using HF maceration techniques, the Wutai(More)
Partition coefficients (DM) for rare earth elements (REE) (La, Ce, Nd, Sm, Dy, Er and Yb) and other trace elements (Ba, Rb, B, Sr, Ti, Y and Nb) between zircon and melt have been calculated from secondary ion mass spectrometric (SIMS) analyses of zircon/melt inclusion pairs. The melt inclusion-mineral (MIM) technique shows that DREE increase in(More)
We have developed a method for mounting and polishing small crystals (<1 mm) to expose melt inclusions for analysis. Individual crystals are mounted in epoxy on one end of a 3.2 mm ¥ 1.3 cm polycarbonate rod. The rod is inserted into a two-piece polishing tool with an adjusting screw to control the amount of sample exposed for grinding and polishing. Thus,(More)
Crystals of halite and sylvite within the Monahans (1998) H5 chondrite contain aqueous fluid inclusions. The fluids are dominantly sodium chloride-potassium chloride brines, but they also contain divalent cations such as iron, magnesium, or calcium. Two possible origins for the brines are indigenous fluids flowing within the asteroid and exogenous fluids(More)
Using Brillouin scattering we have investigated the elastic properties of water under negative pressures. The samples were Hz0 liquid-vapor inclusions in a-quartz which could be heated to their homogenization temperatures (in the range 120-370 “C); on cooling, negative pressures as high as 1000 bars were reached before a vapor bubble nucleated. The velocity(More)
Coeval silicate melt and aqueous synthetic fluid inclusions were INTRODUCTION formed at 800°C and 2000 bars in the quartz-saturated haploIn recent years the study of silicate melt inclusions has granite–H2O–NaCl–KCl system. The equilibrium assemblage congained considerable popularity as a method to charsisted of Ab19·2Or31·1Qtz49·1 melt, quartz, and an(More)
The Mars Exploration Rover Opportunity identified the ferric sulphate mineral jarosite and possible relicts of gypsum at the Meridiani Planum landing site. On Earth, jarosite has been found to form in acid mine drainage environments, during the oxidation of sulphide minerals, and during alteration of volcanic rocks by acidic, sulphur-rich fluids near(More)
The identification and confirmation of bona fide Archean-Paleoproterozoic microfossils can prove to be a challenging task, further compounded by diagenetic and metamorphic histories. While structures of likely biological origin are not uncommon in Precambrian rocks, the search for early fossil life has been disproportionately focused on lesser thermally(More)
High-pressure minerals in meteorites provide clues for the impact processes that excavated, launched and delivered these samples to Earth. Most Martian meteorites are suggested to have been excavated from 3 to 7 km diameter impact craters. Here we show that the Tissint meteorite, a 2011 meteorite fall, contains virtually all the high-pressure phases (seven(More)