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Filtering by: Creator Tamura, Nobumichi Remove constraint Creator: Tamura, Nobumichi Keyword glass alteration Remove constraint Keyword: glass alteration

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  • Data for: Authigenic Mineral Textures in Submarine 1979 Basalt Drill Core, Surtsey Volcano, Iceland

    Description:
    Micrometer-scale maps of authigenic microstructures in submarine basaltic tuff from a 1979 Surtsey volcano, Iceland, drill core acquired 15 years after eruptions terminated describe the initial alteration of oceanic basalt in a low temperature hydrothermal system. An integrative investigative approach uses synchrotron source X-ray microdiffraction (µXRD), microfluoresence (µXRF), micro-computed tomography (µCT), and scanning transmission electron microscopy (S/TEM) coupled with Raman spectroscopy to create finely resolved spatial frameworks that record a continuum of alteration in glass and olivine. Micro-analytical maps of vesicular and fractured lapilli in specimens from 157.1, 137.9, and 102.6 m depth, and borehole temperatures of 83, 93.9 and 141.3 °C measured in 1980, respectively, describe the production of nanocrystalline clay mineral, zeolites, and Al-tobermorite in diverse microenvironments. Irregular alteration fronts at 157.1 m depth resemble microchannels associated with biological activity in older basalts. By contrast, linear microstructures with little resemblance to previously described alteration features have nanocrystalline clay mineral (nontronite) and zeolite (amicite) texture. The crystallographic preferred orientation rotates around an axis parallel to the linear feature. Raman spectra indicating degraded and poorly-ordered carbonaceous matter of possible biological origin are associated with nanocrystalline clay mineral in a crystallographically-oriented linear microstructure in altered olivine at 102.6 m and with sub-circular nanoscale cavities in altered glass at 137.9 m depth. Although evidence for biotic processes is inconclusive, the integrated analyses describe the complex organization of previously unrecognized mineral texture in very young basalt. They provide a foundational mineralogical reference for longitudinal, time-lapse characterizations of palagonitized basalt in oceanic environments.
    Keyword:
    micrometer-scale maps, x-ray microdiffraction, glass alteration, Surtsey Volcano, and submarine basalt
    Subject:
    volcanology
    Creator:
    Couper, Samantha, Parkinson, Dula, Miyagi, Lowell M. , Czabaj, Michael W., Stan, Camelia V. , Moore, James G. , Ivarsson, Magnus, Jackson, Marie D., and Tamura, Nobumichi
    Owner:
    BRIAN MCBRIDE
    Based Near Label Tesim:
    Surtsey, South, Iceland
    Language:
    English
    Date Uploaded:
    07/11/2019
    Date Modified:
    10/03/2024
    Date Created:
    2016-01-01 to 2019-07-11
    License:
    CC BY NC - Allows others to use and share your data non-commercially and with attribution.
    Resource Type:
    Dataset
    Identifier:
    https://doi.org/10.7278/S50D-VJND-8V00