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Found 32 results.

Integrated Mineral, Whole-Rock Geochemistry and Isotopic dataset of the Transminas and Pirenópolis Dike Swarms, Southeastern and Central Brazil

This dataset includes new geochemical and isotopic analyses for 46 samples from the Transminas and Pirenópolis dike swarms in southeastern and central Brazil. It comprises whole-rock major and trace element compositions, and Sr-Nd-Pb isotopes. The new analyses are presented for 46 samples using the bulk and in-situ data templates developed by EarthChem. Analytical work was conducted at the Geoanalítica Core Facility of the Instituto de Geociências, University of São Paulo, and at the Geochronology Laboratory of the University of Brasília, both in Brazil.

Expert dataset: A whole rock geochemical dataset for magmatic rocks drilled on the mid-Norwegian margin

Other

Chemical analyses of the Eastern Australian Potassic Suite: Whole-rock major, trace, and volatile element geochemistry

These data represent the most complete set of analyses of the Eastern Australian Potassic suite. The data include whole-rock major-, trace-, and volatile-element analyses including loss-on-ignition measurements for 48 samples from 21 spatially distinct leucite-bearing volcanic surface expressions. These expressions range from topographically prominent volcanic edifices and mounds, through to lava flows, with four sample locations (8 samples total) coming from active quarry sites. Location and elevation data as well as methods used are provided. Trace-element data are available for 45 samples and include a total of 41 elements, while volatile-element data are available for 47 samples. All samples have major element analyses (10 elements). This is an update on the dataset provided in version 1 (https://doi.org/10.25625/AB5PLG). Additional information on the sample texture, description, and analytical methods has been added. This update also rectifies mismatches between some trace-element analyses and the corresponding samples. Data for Sn have been removed due to poor accuracy and precision.

X-ray fluorescence data of the varved sediment record (HZM19) from Holzmaar, Germany

The elemental composition of the composite sediment record from HZM19 was obtained using the ITRAX XRF Core Scanner at the GEOPOLAR lab (University of Bremen) using a Cr tube with the following settings: exposure time: 5 s, voltage: 30 kV, and current: 50 mA. The step size was set to 200 µm. Prior to measurements and due to scanning times >7 h, core sections were covered with plastic foil (Chemplex Thin-Film). The dataset was cleaned following measurements, i.e. only data points remain that pass the following conditions: 1. counts per seconds >39.000; 2. MSE <15, and 3. validity equals 1. All values are provided in counts (cts). Here only the continuous XRF records of the composite profile is documented. Ages refer to Birlo et al. (2023) and the related dataset is Model D available via doi:10.1594/PANGAEA.949292.

Elemental pigment (hyperspectral imaging) data of the varved sediment record (HZM19) from Holzmaar, Germany

Hyperspectral image (HSI) scanning of the composite record from Holzmaar (HZM19) was measured using a Specim PFD-CL-65-V10 E line scan camera (University of Bern, Switzerland). Data were processed using the ENVI software following the workflow of Butz et al. (2015, doi10.1117/1.JRS.9.096031): data were white-corrected, masked for cracks in the sediment surface and Relative Absorption Band Depths (RABDs) were computed for 2mm wide subsets. RABD671 (band depths from 640 to 702 nm) for Total Chloropigments-a (TChl-a), RABD845 (790 - 900 nm) for Bacteriopheopigments-a (Bphe-a), and RABD620 (600 - 640 nm) for Phycocyanin (PhyCy). To translate HSI indices into absolute concentrations, a pigment extraction was performed at the University of Bern using 23 samples covering the full range of RABD671 and RABD845 index values. Ca 1 g of wet sediment was treated with 100 % acetone following the method of Lami et al. (1994, doi:10.1007/BF00684032) and extractions were measured using a Shimadzu UV-1800 spectrophotometer to obtain bulk concentrations of TChl-a and Bphe-a in µg/g dry sediment using a molar extinction coefficient for TChl-a and Bphe-a. A proxy-proxy calibration was carried out using an ordinary least square regression. After all, only 1.42 % and 0.77 % of datapoints are outside of the calibration ranges for Chl-a (calibration range: 12.75 – 1202.68 µg/g, intercept = -4799.52, slope= 4756,45, r² = 0.8, p-val = 0.00, RMSEP 10-fold = 169.03, RMSEP % = 14.05) and Bphe-a (calibration range 0.38 – 345.12 µg/g, intercept = -1295,8, slope= 1319,7, r² = 0.94, p-val = 0.00, RMSEP 10-fold = 25.26, RMSEP % = 7.32). Ages refer to Birlo et al. (2023) and the related dataset is Model D available via doi:10.1594/PANGAEA.949292.

Magnetic susceptibility data of the varved sediment record (HZM19) from Holzmaar, Germany

Scanning of magnetic susceptibility for all core sections of HZM19 has been carried out using the Bartington MS2 point sensor with step size set to 4 mm. Here only the continuous record of the composite profile is documented. Ages refer to Birlo et al. (2023) and the related dataset is Model D available via doi:10.1594/PANGAEA.949292.

Spectrophotometer data for calibration of HSI index of the varved sediment record (HZM19) from Holzmaar, Germany

To calibrate the hyperspectral imaging (HSI) index values from the sediments of Holzmaar (HZM19) to concentration, a spectrophotometrically measured pigment analysis (Butz et al., 2015; doi:10.1117/1.JRS.9.096031) was performed for 23 samples. These samples were selected to cover a wide range of pigment concentrations as documented by HSI scanning. Approximately 1 g of wet sediment was treated with 100 % acetone according to the method of Lami et al. (1994; doi:10.1007/BF00684032), and the extracts were measured with a Shimadzu UV-1800 spectrophotometer to obtain the mass concentration of Chl-a and Bphe-a in µg/g dry sediment using a mass extinction coefficient for Chl-a (Fiedor et al, 2002; doi:10.1562/0031-8655(2002)0760145POTBCS2.0.CO2) and for Bphe-a (Jeffrey and Humphrey, 1975; doi:10.1016/S0015-3796(17)30778-3).

U-Pb age, whole rock and mineral composition of the Angicos Plutonism (Angicos Batholith and Poço da Oiticica Stock) from northern Borborema Province, NE Brazil

This dataset comprises new chemical, isotopic and geochronological analyses for 14 samples from the Angicos Plutonism (Angicos Batholith and Poço da Oiticica Stock) from northern Borborema Province, NE Brazil. Whole rock major and trace element compositions as well as mineral oxide compositions for feldspars, biotite, and Fe-oxides. New analyses on 14 samples are presented in the bulk and in-situ data templates developed by EarthChem. A compilation of all new analyses and previous whole-rock data from Jardim de Sá (1994) are also provided. Analyses were carried out at the Geoanalítica Core Facility at the Instituto de Geociências, University of São Paulo, Brazil. The data are reported with the EarthChem/ DIGIS data templates (IEDA, 2022).

Integrated Whole-Rock Geochemistry and Isotopic dataset of the Vitória Dike Swarm

This dataset includes new geochemical and isotopic analyses for 10 samples from the Vitória dike swarm in southeastern Brazil. Analytical work was conducted at the Geoanalítica Core Facility of the Instituto de Geociências, University of São Paulo, and at the Geochronology Laboratory of the University of Brasília, both in Brazil.

GDGTs in sediment core Haem13 from lake Hämelsee

This dataset provides glycerol dialkyl glycerol tetraethers (GDGTs) concentrations for the Lateglacial sediment sequence retrieved from Lake Hämelsee (Germany) in 2013. GDGTs concentrations (ng/g) are presented against both depth (m) and age (cal yr. BP). The GDGTs dataset was used to calculate the GDGT-0/crenarchaeol ratio, which was interpreted to represent lake water oxygenation, which, given the local settings, was likely driven by changes in windiness. Additionally, the GDGT dataset was used to calculate the degree of methylation of 5-methyl brGDGTs (MBT'5me), which can be used to reconstruct past temperature change through translation MBT'5me into mean temperature of the months above freezing. As such, the GDGT data provides information on LGIT climate dynamics at lake Hämelsee. Of the 167 samples used for lipid extraction (see https://doi.pangaea.de/10.1594/PANGAEA.964524), the alcohol/fatty acid fraction of 94 samples was further processed to analyse glycerol dialkyl glycerol tetraethers (GDGTs), which are membrane lipids of certain archaea and bacteria (Schouten et al., 2013). In short, a known amount of internal standard was added to each fraction, which was then redissolved in hexane:isopropanol 99:1 and passed over a 0.45 µm PTFE filter prior to injection on a Agilent 1260 Infinity ultra-high performance liquid chromatograph coupled to an Agilent 6130 single quadrupole mass spectrometer following the settings and elution protocol of Hopmans et al. (2016). A minimum peak area of 3000 and a signal-to-noise ratio of >3 was maintained as detection limit. Quantification of the GDGTs is based on the assumption that the mass spectrometer equally responds to the GDGTs and the internal standard. All analyses were performed in the laboratories of Utrecht University, the Netherlands.

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