Assessment and Use of NGR Instrumentation on the &lt;i&gt;JOIDES Resolution&lt;/i&gt; to Quantify U, Th, and K Concentrations in Marine Sediment

Dunlea, Ann G.; Murray, Richard W; Harris, Robert N.; Vasiliev, Maxim A.; Evans, Helen F; Spivack, Arthur J.; Dhondt, Steven

doi:10.5194/sd-15-57-2013

Cited by 14 publications

(21 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, NGR logging required 30-60 min measurement time per core and another ~10 min for core, software, and data handling. Additional information may be found in Vasiliev et al (2011) and Dunlea et al (2013).…”

Section: Natural Gamma Radiation Loggermentioning

confidence: 99%

Methods

Tada¹,

Murray²,

Zarikian³

et al. 2015

Proceedings of the IODP

View full text Add to dashboard Cite

Section: Natural Gamma Radiation Loggermentioning

confidence: 99%

Methods

Tada¹,

Murray²,

Zarikian³

et al. 2015

Proceedings of the IODP

View full text Add to dashboard Cite

“…Similar to Dunlea et al . [], we found a density correction was required prior to the comparison of NGR‐derived estimates with ICP and XRF measurements (equations ). The density correction factor consists of the ratio between wet bulk density and dry grain density [ Dunlea et al ., ].…”

Section: Discussionmentioning

confidence: 99%

“…These data sets are complemented by previously published results from Sites U1366–U1369 [Exp. 329; Dunlea et al ., ] and Site U1414 [Exp. 344; Yan and Shi , ; Figure 2].…”

Section: Methodsmentioning

confidence: 99%

“…To incorporate the probability of a decay event being observed in their low‐count spectra, Dunlea et al . [] adopted a slightly different method and compared the measured NGR spectra to spectra generated by Monte Carlo simulations to obtain U and Th concentrations. Here we show that counts in the U and Th windows are sufficient (Figures g and h) to accurately estimate the U and Th element content in the sample after a 5 min measurement (Figures b and c).…”

Section: Quantifying K U and Th Contents Using Shipboard Natural Gamentioning

confidence: 99%

“…The NGR intensity measured at an energy level characteristic for K, U, or Th is proportional to the content of that element in the sediment. Hence, the current NGR setup on JOIDES Resolution allows for an estimation of the K, U, and Th contents from the shipboard NGR energy spectra [ Gilmore , ; Dunlea et al ., ]. In this paper, we provide MATLAB codes that calculate the sedimentary K, U, and Th contents from the NGR spectra.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Vleeschouwer

Dunlea

Auer

et al. 2017

Geochem Geophys Geosyst

122

View full text Add to dashboard Cite

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 40 K, 232 Th, and 238 U 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.

show abstract

Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361

Tauxe

Sugisaki

Jiménez-Espejo

et al. 2015

Earth and Planetary Science Letters

View full text Add to dashboard Cite

IODP Expedition 318 drilled Site U1361 on the continental rise offshore of Adelie Land and the Wilkes sub-glacial basin. The objective was to reconstruct the stability of the East Antarctic Ice Sheet (EAIS) during Neogene warm periods, such as the late Miocene and the early Pliocene. The sedimentary record tells a complex story of compaction, and erosion (thus hiatuses). Teasing out the paleoenvironmental implications is essential for understanding the evolution of the EAIS. Anisotropy of magnetic susceptibility (AMS) is sensitive to differential compaction and other rock magnetic parameters like isothermal remanence and anhysteretic remanence are very sensitive to changes in the terrestrial source region. In general, highly anisotropic layers correspond with laminated clay-rich units, while more isotropic layers are bioturbated and have less clay. Layers enriched in diatoms are associated with the latter, which also have higher Ba/Al ratios consistent with higher productivity. Higher anisotropy layers have lower porosity and moisture contents and have fine grained magnetic mineralogy dominated by maghemite, the more oxidized form of iron oxide, while the lower anisotropy layers have magnetic mineralogies dominated by magnetite. The different magnetic mineralogies support the suggestion based on isotopic signatures by Cook et al. (2013) of different source regions during low productivity (cooler) and high productivity (warmer) times. These two facies were tied to the coastal outcrops of the Lower Paleozoic granitic terranes and the Ferrar Large Igneous Province in the more inland Wilkes Subglacial Basin respectively. Here we present evidence for a third geological unit, one eroded at the boundaries between the high and low clay zone with a "hard" (mostly hematite) dominated magnetic mineralogy. This unit likely outcrops in the Wilkes subglacial basin and could be hydrothermally altered Beacon sandstone similar to that detected by Craw and Findlay (1984) in Taylor Valley or the equivalent to the Elatina Formation in the Adelaide Geosyncline in Southern Australia (Schmidt and Williams, 2013). Correlation of the "hard" events with global oxygen isotope stacks of Zachos et al. (2001) and Lisiecki and Raymo (2005) To whom it may concern:Please find enclosed our revised manuscript entitled, "Geology of the Wilkes Land Sub-basin and Stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361" for consideration for publication in Earth and Planetary Science Letters. We have read the reviews carefully and responded as appropriate. Thank you for your consideration of our revised manuscript.Sincerely, Lisa TauxeCover LetterResponse to Reviews for "Geology of the Wilkes Land Sub-basin and Stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361", by Tauxe et al. Editor:Alternatively, you may submit the data to a publicly accessible database or repository such as PANGEA and indicate in the paper where the data can be accessed. If you decide to u...

show abstract

Assessment and Use of NGR Instrumentation on the <i>JOIDES Resolution</i> to Quantify U, Th, and K Concentrations in Marine Sediment

Abstract: No abstract available. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.15.05.2013" target="_blank">10.2204/iodp.sd.15.05.2013</a>

Cited by 14 publications

References 21 publications

Methods

Methods

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

Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361

Contact Info

Product

Resources

About