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11 hits

  • Thumbnail for 57-K-91
    57-K-91

    This vesicular basalt contains microphenocrysts of olivine and orthopyroxene, both of which are also lesser components of the groundmass which consists mainly of uniformly-sized plagioclase laths. The olivine phenocryst have weak reaction rims. Some plagioclase is zoned and sieved.

  • Thumbnail for CM4
    CM4

    The vesicles in this microporphyritic vesicular basalt are substantially smaller than the other Carr Mountain samples, though composition remains similar. More calcite permeates the groundmass, in which plagioclase microlites are visible. Unaltered augite and olivine microphenocrysts are observed. An isotropic zeolite, presumably analcite, is seen infilling several vesicles.

  • Thumbnail for SG1A
    SG1A

    Plagioclase laths of varying sizes and orientations represent the bulk of this thin section. Augite is present, though in noticeably smaller quantities and olivine only in trace amounts. Tiny opaques pervade the sample.

  • Thumbnail for CM3
    CM3

    Augite and olivine are the two crystalline phases in this 'cloudy' vesicular basalt. Iddingsite replacement of olivine is almost comprehensive; commonly, iddingsite nodes are the only indication of olivine's presence. The groundmass is microcrystalline and altered enough as to be unidentifiable.

  • Thumbnail for 59-K-91
    59-K-91

    This vesicular basalt contains microphenocrysts of olivine and orthopyroxene, both of which are also lesser components of the groundmass which consists mainly of uniformly-sized plagioclase laths. The olivine phenocryst have weak reaction rims. Some plagioclase is zoned and sieved.

  • Thumbnail for CM2A
    CM2A

    Augite and olivine are the two predominant crystalline phases in this vesicular basalt and define a microporphyritic fabric. Iddingsite replacement of olivine is minimal. As smaller crystals, both phases, along with opaques, a feldspar, and glass, comprise the groundmass.

  • Thumbnail for CM2A
    CM2A

    Augite and olivine are the two predominant crystalline phases in this vesicular basalt and define a microporphyritic fabric. Iddingsite replacement of olivine is minimal. As smaller crystals, both phases, along with opaques, a feldspar, and glass, comprise the groundmass.

  • Thumbnail for BATUR 94 CR
    BATUR 94 CR

    Sieve textured plagioclase blocks and laths dominate the phenocrystic population in this microporphyritic vesicular basalt. Clinopyroxene phenocrysts are less abundant and olivine less abundant still. All three phases are found in the groundmass. Groundmass clinopyroxene and olivine are more abundant than in BATUR 94 FL.

  • Thumbnail for SG2A
    SG2A

    Plagioclase microlites and small rounded crystals of augite and olivine define this thin section. The interstices between crystals are filled with reddish-brown glass.

  • Thumbnail for BATUR 94 FL
    BATUR 94 FL

    Sieve textured plagioclase blocks and laths dominate the phenocrystic population in this microporphyritic vesicular basalt. Clinopyroxene phenocrysts are less abundant. Both phases are found with glass as constituents of the groundmass.

  • Thumbnail for 58-K-91
    58-K-91

    Unoriented plagioclase laths and interstitial glass and clinopyroxene make up the groundmass of this vesicular basalt. Olivine and orthopyroxene microphenocrysts are scattered throughout.