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9 hits

  • Thumbnail for JPN-13
    JPN-13

    As is characteristic of a harzburgite, this sample is greater than 90% olivine, with a few large clinopyroxene grains, fracture-infilled serpentine, and occasional, moderately-sized rutile grains making up the remaining constituents of the rock. Serpentinization is minimal.

  • Thumbnail for SYH-1D-2
    SYH-1D-2

    Glaucophane, muscovite, sphene, and elongate aggregates of epidote-group minerals define the foliation in this thin section. Poikiloblastic garnet and omphacite grains contain inclusions which include glaucophane and rutile and the host minerals show resorption textures.

  • Thumbnail for SYH-1II
    SYH-1II

    Like the other blueschists, aligned glaucophane, clinozoisite, and sphene define the foliation, however, this sample lacks omphacite and garnet, and contains quartz and aragonite instead. These latter two phases are interstitial and occur in minor amounts,

  • Thumbnail for SS-4
    SS-4

    Randomly oriented biotite phenocrysts dominate this thin section. The interstices between phenocrysts contain prisms of k-feldspar, anhedral masses of calcite and nephaline, and radial splays of muscovite. Opaques are equant and up to 0.5mm in diameter. The nephaline phase has a bluish cast in cross-polarized light. The groundmass phases are cross-cut by a mesh-work of clays and various alteration products. Slightly diamond-shaped rutile is pervasive throughout.

  • Thumbnail for SYH-1DD
    SYH-1DD

    Glaucophane, muscovite, sphene, and elongate aggregates of epidote-group minerals define the foliation in this thin section. Poikiloblastic garnet and omphacite grains contain inclusions which include glaucophane and rutile.

  • Thumbnail for SS-5
    SS-5

    Biotite and olivine dominate this sample. The olivine is frequently twinned and highly fractured. In the interstices between olivine grains grows large, anhedral biotite grains. Both phases have a sieve-like, pock-marked appearance. Rutile and opaques, all equant in shape, are plentiful.

  • Thumbnail for SYH-1EE
    SYH-1EE

    Allotriomorphic omphacite and clinozoisite are intergrown with one another, with clinozoisite occurring frequently as inclusions within the omphacite crystals. The occurrence of muscovite is typically contained to polycrystalline nodes with radiating crystals. The conspicuous rutile grain in the center with radiating veinlets has a rim of plagioclase buffering it from the surrounding material. It contains inclusions of chlorite and sphene. Sphene is abundant as large, subhedral clasts.

  • Thumbnail for SYH-1A
    SYH-1A

    This crenulated foliation is defined by elongate omphacite interleaved with clinozoisite, sphene, chlorite, muscovite, and the rarer glaucophane crystals. Euhedral though fractured garnets contain chlorite, muscovite, and omphacite inclusions. Hexagonal porphyroclasts of randomly-oriented chlorite are scattered throughout.

  • Thumbnail for SYH-1R
    SYH-1R

    Aligned, elongate, millimetric-scale actinolite crystals dominate this thin section. Layers of actinolite crystals are interleaved with layers of chlorite. Basal sections of actinolite, which show fabulous amphibole cleavage are strongly plucked, leaving patchy void spaces throughout the thin section.