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12 hits

  • Thumbnail for SYH-1F
    SYH-1F

    A contact between blueshist and an omphacite boudin is captured in this thin section. The blueschist side is strongly foliated due to aligned glaucophane with interspersed sphene and minor muscovite and chlorite. The contact itself is an aggregate of sphene with interstitial chlorite and clinozoisite. Omphacite is the dominant mineral on the other side of the contact, though some glaucophane, muscovite, sphene, and clinozoisite is present. Quartz rims surround reddish opaques.

  • Thumbnail for SYH-3D-1
    SYH-3D-1

    This thin section consists of several zones. The first, a fine-grained glaucophane schist with accessory sphene and zoisite. Microcrenulations cause the boundaries between individual glaucophane crystals to blur. This zone is abruptly cut by a green, omphacite-rich band. In the third zone, the glaucophane fabric is interleaved with elongate aggregates of omphacite and other accessory minerals.

  • Thumbnail for SYH-1CC
    SYH-1CC

    The foliation in this thin section, defined primarily by aligned glaucophane and clinozoisite, as well as strings of euhedral and aggregated sphene, wraps around larger, equant omphacite and glaucophane grains. The grain size is larger than many others in this suite and the foliation weaker.

  • 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 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 GR-05
    GR-05

    The omphacite in this thin section is variably sized. Larger crystals are interspersed with granular aggregates; all are dusty due to alteration to clays. Interstitial muscovite is common and variation in birefringence indicates differing compositions or degrees of alteration of the micaceous phase.

  • Thumbnail for SYH-1E
    SYH-1E

    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 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-3D-2
    SYH-3D-2

    This thin section consists of several zones. The first, a fine-grained glaucophane schist. The boundaries between individual glaucophane crystals frequently blur. Aggregates of sphene are stretched out lines paralleling the complexly folded foliation. This zone is abruptly cut by a green, omphacite-rich band, bordered on each sided by a greater concentration of sphene. In the third zone, the glaucophane fabric is interleaved with elongate aggregates of omphacite, epidote and sphene.

  • 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-3A-3
    SYH-3A-3

    This rock grades from an omphacite-rich zone into a muscovite-rich zone, and yet again into a glaucophane and chlorite-rich zone. The transitions between each section is rather abrupt. Micaceous phases are strongly aligned to define a foliation. Sphene is noticeably less abundant than in other samples. A k-feldspar porphyroclast surrounded by radiating chlorite is observed in the chlorite-glaucophane region.

  • Thumbnail for SYH-1M
    SYH-1M

    Randomly oriented, irregularly-shaped omphacite crystals comprise a boudin within the blueschist. In cracks within this boudin are aligned muscovite, glaucophane, and chlorite crystals. In one corner of the thin section, a titanite aggregate forms a reddish inclusion.