API src

Found 32 results.

Dry mass concentrations of individual n-alkanes in sediment core Haem13 from lake Hämelsee

This dataset provides concentrations of n-alkanes for the Lateglacial sediment sequence retrieved from Lake Hämelsee (Germany) in 2013. Concentrations of n-alkanes (ug/g), the Carbon Preference Index (CPI) and the Average Chain Length C21-C33 (ACL) are all presented against both depth (m) and age (cal yr. BP). The n-alkane concentration data provides information on the Lateglacial dynamics of local plant productivity, whereas the ACL and CPI of the sediment samples were determined to estimate origin and preservation condition. A total of 167 samples from the Lateglacial section of the core were processed using a Dionex 350 accelerated solvent extraction (ASE) system. Solid phase extraction (SPE) was used to separate the extracts into an aliphatic, aromatic and alcohol/fatty acid fraction. Separation was achieved by loading the extracts on activated silica columns and eluting each fraction with hexane, hexane/DCM (1:1 v/v) and DCM/MeOH (9:1 v/v) successively. The aliphatic fraction, containing the n-alkanes, was analyzed by gas chromatography-mass spectrometry (GC/MS). The peak areas for each n-alkane homologue were compared to the peak areas from an internal standard (5α-androstane) and an external n-alkane standard mixture for absolute quantification. We refer to Rach et al. (2020) for further details on the exact analytical setup. All measurements were performed in the laboratories of GeoForschungsZentrum Potsdam.

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

Other

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.

Estimated adjusted depth of CO2 of FB2001 drill core from Messel

This table contains atmospheric CO2-estimates based on stomata retrieved in the Messel fossil pit and published by Grein (2010) and Grein et al. (2011). The data is based on leaves retrieved from the Messel fossil pit (earliest Middle Eocene; 47.66 to 47.22 Ma). The leaves were microscopically analysed for their stomata density and which was then converted into atmospheric CO2 content (cf. Grein 2010, Grein et al., 2011 for details about the algorithm). The plant fossils were listed with their original outcrop depth which was marked down relative to marker beds. We projected the outcrop depth (m) onto the FB2001 drill core depth using the marker beds as reference horizons. The age (Ma) as well as mean, maximum and minimum of the CO2 estimates are reported as well as the respective plant species.

Recurrence times of siderite layers of FB2001 drill core from Messel

To investigate variability and drivers of extreme precipitation events under high greenhouse gas concentrations prevalent during the Eocene we computed recurrence times of Fe/Ti peaks in the XRF scanning record of FB2001, reflecting siderite layers that are interpreted to reflect strong precipitation events. Fe/Ti-peaks were detected based on a peak-detection algorithm, followed by counting over a sliding window. Recurrence times were calculated based on the number of Fe/Ti peaks per 5 ka window. Upper and lower boundaries of recurrence times are calculated based on bootstrapping. The record covers the period 47.66 to 47.22 Ma

Mean Annual Air Temperatures of FB2001 drill core from Messel

This table contains Mean Annual Temperatures (MAT) reconstructed using branched GDGTs obtained on core FB2001 from Messel (earliest Middle Eocene; 47.66 to 47.22 Ma), relative to the core depth and age. The error given reflects the calibration error. Samples from the depth interval 17.38 to 30.88 m were analyzed in Frankfurt by high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) on a Shimadzu UFLC device coupled to an AB Sciex 3200QTrap. Samples from the interval between 35.94 to 70.94 m core analyzed at RWTH Aachen University, Aachen (Germany), using an Agilent 1260 Infinity II HPLC coupled to an Agilent LC/MSD XT mass spectrometer.

XRF Fe/TI and K/Ti ratios of FB2001 drill core from Messel

The data contains Fe/Ti and K/Ti ratios obtained via XRF core scanning of drill core FB2001 from the Messel fossil pit (earliest Middle Eocene; 47.66 to 47.22 Ma) versus core depth and age. Scanning was performed at the Institute of Institute of Earth Sciences, Heidelberg University (Germany), with an Avvatech (Gen. IV) X-Ray Fluorescence Scanner. The purpose of this analysis was to objectively detect and quantify the occurrence of siderite layers in the Messel oil shale. These siderite layers are interpreted to represent extreme precipitation events.

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.

1 2 3 4