Bulk density (GRA)

Gamma ray attenuation (GRA) data were acquired using a Cs-137 collimated source and a sodium iodide (thallium), or NaI(Tl), scintillation detector. The signal was calibrated using water and aluminum standards to provide a proxy for bulk density. This measurement was performed by a sensor mounted on either the Whole-Round Multisensor Logger (WRMSL) or the Special Task Multisensor Logger (STMSL); which track was used for a given data set is indicated in the data.

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
    Offset (cm): position of the observation made, measured relative to the top of a section.
    Depth CSF-A (m): location of the observation expressed relative to the top of a hole.
    Depth [other] (m): location of the observation expressed relative to the top of a hole. The location is presented in a scale selected by the science party or the report user.
    Bulk density (GRA) (g/cm3): computed bulk density of sample.
    Configuration filename: filename of configuration file.
    Run filename: filename of raw data.
    Timestamp (UTC): date and time the observation was made.
    Instrument: abbreviation or mnemonic for the GRA sensing device used to make this observation (GRA1 or GRA2).
    Instrument group: abbreviation or mnemonic for the data collection device (logger) used to acquire this observation (WRMSL).
    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.