Gas safety report

This composite report returns data from two different gas chromatograph configurations (GC3 and NGA). Each row combines data from several measurements made on the same sample at the same time for a particular headspace or vacutainer sample. If data do not exist for a particular expedition, the column does not appear. Gas samples were measured by gas chromatography and either flame ionization detection (GC-FID) or thermal conductivity detection (GC-TCD). Reported analytes may include methane, ethane, ethene, propane, propene, n-butane, i-butane, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, nitrogen, oxygen, carbon monoxide, carbon dioxide, and hydrogen sulfide. When data are available, methane to (ethane + ethene) ratio (C1/C2 ratio) is reported. To identify individual samples and tests, see each separate analysis (GC3, NGAFID, and/or NGATCD).

Data File format

    Exp: expedition number
    Site: site number
    Hole: hole number
    Core: core number
    Type: type indicates the coring tool used to recover the core (typical types are F, H, R, X).
    Sect: section number.
    A/W: archive (A) or working (W) section half.
    Top offset on section (cm): position of the upper edge of the sample, measured relative to the top of the section.
    Bottom offset on section (cm): position of the lower edge of the sample, measured relative to the top of the section.
    Top depth CSF-A (m): location of the upper edge of the sample expressed relative to the top of the hole.
    Top depth [other] (m): location of the upper edge of the sample expressed relative to the top of the hole. The location is presented in a scale selected by the science party or the report user.
    Test list: sample collection method: HS = headspace, VAC = vacuum gas sampler (Vacutainer tube).
    Methane (ppmv): C1 (CH4).
    Ethene (ppmv): C2= (C2H2).
    Ethane (ppmv): C2 (C2H4).
    Propene (ppmv): C3= (C3H6).
    Propane (ppmv): C3 (C3H8).
    iso-Butane (ppmv): i-C4 (C4H10; branched isomer 2-methylpropene): (CH3)3CH.
    n-Butane (ppmv): n-C4 (C4H10; unbranched isomer): CH3CH2CH2CH3.
    iso-Pentane (ppmv): i-C5 (C5H12; branched isomer 2-methylbutane): CH3CH2CH(CH3)2.
    n-Pentane (ppmv): n-C5 (C5H12; unbranched isomer): CH3 (CH2)3CH3.
    iso-Hexane (ppmv): i-C6 (C6H14; branched isomer 2-methylpentane): CH3CH2CH2CH(CH3)2.
    n-Hexane (ppmv): n-C6 (C6H14; unbranched isomer): CH3 (CH2)4CH3.
    iso-Heptane (ppmv): i-C7 (C7H16; branched isomer 2-methylhexane): CH3CHCH3 (CH2)3CH3.
    n-Heptane (ppmv): n-C7 (C7H16; unbranched isomer): CH3 (CH2)5CH3.
    N2 (ppmv): nitrogen.
    O2 (ppmv): oxygen.
    H2S (ppmv): hydrogen sulfide.
    CO2 (ppmv): carbon dioxide.
    c1_c2_gc3 % : ratio of Methane (C1) to Ethane (C2).
    Text ID: automatically generated unique database identifier for a sample, visible on printed labels.
    Test No.: unique number associated with the instrument measurement steps that produced these data.
    Sample comments: observations recorded about the sample itself.
    Test comments: observations about a measurement or the measurement process; some measurement observations may be under Result comments.
    Result comments: observations about a measurement or the measurement process; some measurement observations may be under Test comments.