de.pangaea.dataset779130 und dataset PANGAEA

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https://www.pangaea.de/ information pointOfContact 2026-05-01T03:25:08Z https://doi.pangaea.de/10.1594/PANGAEA.779130 2004-01-01 publication https://doi.org/10.1594/PANGAEA.779130 Dean, Simon M author PANGAEA

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https://www.pangaea.de/ information publisher tableDigital Supplement to: Dean, Simon M (2004): Analysis of NGR spectra from deep-sea sediments in the Philippine Sea, Site 1201. In: Shinohara, M; Salisbury, MH; Richter, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 195, 1-33, https://doi.org/10.2973/odp.proc.sr.195.105.2004 Natural gamma ray measurements are made routinely during core logging using the physical property multisensor track. The instrument provides a measure of the natural decay of radioactive elements in the core, expressed in counts per second, which is generally used as a proxy for the clay content of nonmarginal marine sediments. At Site 1201 spikes of increased gamma ray emissions, up to six times the average for the entire core over depth intervals on the order of 20-50 cm, are observed from the sediments within 50 m of the basement contact. The spikes show a strong correlation with sediment color variations, coinciding with red/brown layers within otherwise green/gray-colored sediments. In this paper, the gamma ray spectra obtained from 21 measurements using a 4-hr counting period are analyzed to obtain the absolute concentration of the radioactive elements K2O, U, and Th in both the intervals with spikes and the intervals with relatively low count rates. In addition, the concentration of these elements is estimated using the spectra obtained from the routine 20-s counting period measurements and which, although exhibiting a great deal of scatter due to the high statistical uncertainty in the original measurements, are roughly similar to those obtained from the 4-hr counting period. Baseline concentrations for U (1 ppm) and Th (5 ppm) match published averages for the amount present in deep-sea clays; the peak concentrations measured correspond to an additional concentration of 100%-200%. The results are compared to those from downhole logging and shipboard inductively coupled plasma-atomic emission spectrometry measurements. The gamma ray spectra results do not support postdepositional fluid flow through the sediment as the source of the enrichment of radioactive elements. It is more likely that the spikes in the gamma ray emissions are simply the result of interbedding sediments from two different sources, one with relatively high concentrations of K2O, U, and Th. completed Dean, Simon M principalInvestigator ODP Ocean Drilling Program theme 1995-01-01 creation PANGAEA

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https://www.pangaea.de/ information pointOfContact copyright copyright CC-BY-3.0: Creative Commons Attribution 3.0 Unported textTable und geoscientificInformation 135.09915 135.09915 19.2977166666666 19.2977166666666 2001-03-31T00:00:00 2001-04-25T00:00:00 460.41 513.46 DEPTH, sediment/rock physicalMeasurement m m Potassium oxide physicalMeasurement Natural gamma-ray spectroscopy tool (NGT) % % Uranium physicalMeasurement Natural gamma-ray spectroscopy tool (NGT) mg/kg mg/kg Thorium physicalMeasurement Natural gamma-ray spectroscopy tool (NGT) mg/kg mg/kg text/tab-separated-values unknown https://doi.pangaea.de/10.1594/PANGAEA.779130?format=textfile download dataset The data set was checked for completeness, correctness, and consistency of metainformation. Validity of used methods was checked and - if applicable - precision and range of data. EVENT LABEL: 195-1201 * LATITUDE: 19.297717 * LONGITUDE: 135.099150 * DATE/TIME START: 2001-03-31T00:00:00 * DATE/TIME END: 2001-04-25T00:00:00 * ELEVATION: -5709.7 m * PENETRATION: 1320 m * RECOVERY: 523.7 m * LOCATION: Philippine Sea * CAMPAIGN: Leg195 * BASIS: Joides Resolution * METHOD/DEVICE: Composite Core 73 cores; 659.6 m cored; 621.3 m drilled; 79.4% recovery 2001-03-31T00:00:00