Peter B. Kelemen

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Geochemical and field evidence suggest that melt transport in some regions of the mantle is localized into mesoscale “channels” that have widths of 0.1–100 m or larger. Nevertheless, the mechanisms for formation of such channels from a grain-scale distribution of melt are poorly understood. The purpose of this paper is to investigate one possible mechanism(More)
This paper presents results of modelling reaction between peridotite and fractionating tholeiitic basalt in simple and complex silicate systems. Reactions are outlined in appropriate binary and ternary silicate systems. In these simple systems, the result of reactions between 'basalt' and 'peridotite' may be treated as a combination of Fe-Mg exchange and(More)
The following is a paper in the Proceedings of the [US] National Academy of Sciences. The methods described in this paper are proprietary. These methods are the property of Columbia University, with US patents pending. We will gladly share details of this method, and the ongoing modeling effort associated with it, in order to pursue the mutual benefit of(More)
Ž . Gabbroic sills intruding dunite in the crust–mantle transition zone MTZ of the Oman ophiolite have textures and compositions very similar to those in modally layered gabbros that form the lower part of the gabbro section in the ophiolite, and different from those in non-layered gabbros near the dike–gabbro transition. The presence of gabbroic sills in(More)
[1] Residual mantle exposures in the accreted Talkeetna arc, Alaska, provide the first rock analog for the arc-parallel flow that is inferred from seismic anisotropy at several modern arcs. The peridotites exposed at the base of the Jurassic Talkeetna arc have a Moho-parallel foliation and indicate dislocation creep of olivine at temperatures of 1000 to(More)
The Trinity peridotite (northern CA) contains numerous lithologic sequences consisting of dunite to harzburgite to spinel lherzolite to plagioclase lherzolite. Previous workers have documented geochemical gradients in these sequences consistent with melt-rock reaction processes occurring around dunites, interpreted to reflect conduits for melt ascent. We(More)
Interpretation of U-series disequilibria in midocean ridge basalts is highly dependent on the bulk partition coefficients for U and Th and therefore the mineralogy of the mantle source. Distinguishing between the effect of melting processes and variable source compositions on measured disequilibria (U-Th-Ra and U-Pa) requires measurement of the radiogenic(More)
Near-surface reaction of CO2-bearing fluids with silicate minerals in peridotite and basalt forms solid carbonate minerals. Such processes form abundant veins and travertinedeposits, particularly in associationwith tectonically exposed mantle peridotite. This is important in the global carbon cycle, in weathering, and in understanding physical-chemical(More)
In late summer, pollen grains originating from Compositae weeds (e.g., mugwort, ragweed) are a major source of allergens worldwide. Here, we report the isolation of a cDNA clone coding for Art v 1, the major allergen of mugwort pollen. Sequence analysis showed that Art v 1 is a secreted allergen with an N-terminal cysteine-rich domain homologous to plant(More)
Mantle peridotite xenoliths from Archean cratons generally have high molar Mg=(Mg C Fe), or Mg#. The best known suites, from the Kapvaal and Siberian cratons, have high modal orthopyroxene (Opx). These high Opx compositions are probably not residues of partial melting. Less well known cratonic xenolith suites from Greenland and North America include high(More)