41 documents found in 287ms
# 1
Blanchet, Cécile L.
Abstract: The database presented here contains radiogenic neodymium and strontium isotope ratios measured on both terrestrial and marine sediments. It was compiled to help assessing sediment provenance and transport processes for various time intervals. This can be achieved by either mapping sediment isotopic signature and/or fingerprinting source areas using statistical tools (see supplemental references). The database has been built by incorporating data from the literature and the SedDB database and harmonizing the metadata, especially units and geographical coordinates. The original data were processed in three steps. Firstly, a specific attention has been devoted to provide geographical coordinates to each sample in order to be able to map the data. When available, the original geographical coordinates from the reference (generally DMS coordinates, with different precision standard) were transferred into the decimal degrees system. When coordinates were not provided, an approximate location was derived from available information in the original publication. Secondly, all samples were assigned a set of standardized criteria that help splitting the dataset in specific categories. We defined categories associated with the sample location ("Region", "Sub-region", "Location", which relate to location at continental to city/river scale) or with the sample types (terrestrial samples – “aerosols”, “soil sediments”, “river sediments” - or marine samples –“marine sediment” or “trap sample”). Thirdly, samples were discriminated according to their deposition age, which allowed to compute average values for specific time intervals (see attached table "Age_determination_Sediment_Cores.csv"). The dataset will be updated bi-annually and might be extended to reach a global geographical extent and/or add other type of samples. This dataset contains two csv tables: "Dataset_Nd_Sr_isotopes.csv" and "Age_determination_Sediment_Cores.csv". "Dataset_Nd_Sr_isotopes.csv" contains the assembled dataset of marine and terrestrial Nd and/or Sr concentration and isotopes, together with sorting criteria and geographical locations. "Age_determination_Sediment_Cores.csv" contains all background information concerning the determination of the isotopic signature of specific time intervals (depth interval, number of samples, mean and standard deviation). Column headers are explained in respective metadata comma-separated files. A human readable data description is provided in portable document format, as well. Finally, R code for mapping the data and running statistical analyses is also available for this dataset (see supplemental references).
# 2
Blanchet, Cécile L.
Abstract: The database presented here contains radiogenic neodymium and strontium isotope ratios measured on both terrestrial and marine sediments. It was compiled to help assessing sediment provenance and transport processes for various time intervals. This can be achieved by either mapping sediment isotopic signature and/or fingerprinting source areas using statistical tools (e.g. Blanchet, 2018b, 2018a). The database has been built by incorporating data from the literature and the SedDB database and harmonizing the metadata, especially units and geographical coordinates. The original data were processed in three steps. Firstly, a specific attention has been devoted to provide geographical coordinates to each sample in order to be able to map the data. When available, the original geographical coordinates from the reference (generally DMS coordinates, with different precision standard) were transferred into the decimal degrees system. When coordinates were not provided, an approximate location was derived from available information in the original publication. Secondly, all samples were assigned a set of standardized criteria that help splitting the dataset in specific categories. We defined categories associated with the sample location ("Region", "Sub-region", "Location", which relate to location at continental to city/river scale) or with the sample types (terrestrial samples – “aerosols”, “soil sediments”, “river sediments”, “rocks” - or marine samples –“marine sediment” or “trap sample”). Thirdly, samples were discriminated according to their deposition age, which allowed to compute average values for specific time intervals (see attached table "Age_determination_Sediment_Cores_V2.txt"). A first version of the database was published in September 2018 and presented data for the African sector. A second version was published in April 2019, in which the dataset has been extended to reach a global extent. The dataset will be further updated bi-annually to increase the geographical resolution and/or add other type of samples. This dataset consists of two tab separated tables: "Dataset_Nd_Sr_isotopes_V2.txt" and "Age_determination_Sediment_Cores_V2.txt". "Dataset_Nd_Sr_isotopes_V2.txt" contains the assembled dataset of marine and terrestrial Nd and/or Sr concentration and isotopes, together with sorting criteria and geographical locations. "Age_determination_Sediment_Cores_V2.txt" contains all background information concerning the determination of the isotopic signature of specific time intervals (depth interval, number of samples, mean and standard deviation). Column headers are explained in respective metadata comma-separated files. A full reference list is provided in the file “References_Database_Nd_Sr_isotopes_V2.rtf”. Finally, R code for mapping the data and running statistical analyses is also available for this dataset (Blanchet, 2018b, 2018a).
# 3
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 4
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 5
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 6
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 7
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 8
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 9
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
# 10
KTB, WG Geophysics
Abstract: The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).
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