Quantifying K, U, and Th contents of marine sediments using shipboard natural gamma radiation spectra measured on DV JOIDES Resolution

David De Vleeschouwer*, Ann G. Dunlea, Gerald Auer, Chloe H. Anderson, Hans Brumsack, Aaron de Loach, Michael Gurnis, Youngsook Huh, Takeshige Ishiwa, Kwangchul Jang, Michelle A. Kominz, Christian März, Bernhard Schnetger, Richard W. Murray, Heiko Pälike, Expedition 356 Scientific Participants

*Corresponding author for this work

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

During International Ocean Discovery Program (IODP) expeditions, shipboard-generated data provide the first insights into the cored sequences. The natural gamma radiation (NGR) of the recovered material, for example, is routinely measured on the ocean drilling research vessel DV JOIDES Resolution. At present, only total NGR counts are readily available as shipboard data, although full NGR spectra (counts as a function of gamma-ray energy level) are produced and archived. These spectra contain unexploited information, as one can estimate the sedimentary contents of potassium (K), thorium (Th), and uranium (U) from the characteristic gamma-ray energies of isotopes in the 40K, 232Th, and 238U radioactive decay series. Dunlea et al. (2013) quantified K, Th, and U contents in sediment from the South Pacific Gyre by integrating counts over specific energy levels of the NGR spectrum. However, the algorithm used in their study is unavailable to the wider scientific community due to commercial proprietary reasons. Here, we present a new MATLAB algorithm for the quantification of NGR spectra that is transparent and accessible to future NGR users. We demonstrate the algorithm's performance by comparing its results to shore-based inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-emission spectrometry (ICP-ES), and quantitative wavelength-dispersive X-ray fluorescence (XRF) analyses. Samples for these comparisons come from eleven sites (U1341, U1343, U1366-U1369, U1414, U1428-U1430, and U1463) cored in two oceans during five expeditions. In short, our algorithm rapidly produces detailed high-quality information on sediment properties during IODP expeditions at no extra cost.

Original languageEnglish
Pages (from-to)1053-1064
Number of pages12
JournalGeochemistry, Geophysics, Geosystems
Volume18
Issue number3
DOIs
Publication statusPublished - Mar 2017
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2017. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Keywords

  • downhole logging
  • IODP
  • natural gamma radiation
  • physical properties

Fingerprint Dive into the research topics of 'Quantifying K, U, and Th contents of marine sediments using shipboard natural gamma radiation spectra measured on DV<i> JOIDES</i> <i>Resolution</i>'. Together they form a unique fingerprint.

Cite this