Organic matter (OM) is known to be an important reductant in sediment-hosted base metal deposits like the European Kupferschiefer. However, the precise nature of interactions between OM and hydrothermal fluids are still debated as well as how the interconnected reactions develop over geological timescales.
This dataset provides for the first time bulk, compositional and stable isotope data of hydrocarbons, biomarkers and organonitrogen, -sulfur and-oxygen (NSO) compounds for the mineralized Kupferschiefer Spremberg-Graustein field in Eastern Germany based on samples from two drill cores. The study aims to help to better understand the role that organic matter plays during the mineralisation and formation of the sedimentary ore deposit within the Kupferschiefer with a focus on stable hydrogen isotope compositions and NSO compositional data to especially address the origin and to assess the oxidative nature of the brines that caused the mineralization in the Spremberg-Graustein field.
The data publication includes bulk, compositional and stable isotope data on inorganic metals and organic matter. The data about metal contents were generated using ICP-MS while those on the organic matter were generated using Rock-Eval pyrolysis, a microscope, a Soxhlet apparatus, medium pressure liquid chromatography (MPLC), gas chromatography with flame ionization (GC-FID) and mass spectrometric detection (GC-MS), gas chromatography isotope ratio mass spectrometry (GC-IRMS) and ultrahigh resolution mass spectrometry (Fourier Transform ion cyclotron resonance mass spectrometry, FT-ICR-MS) with Electrospray ionization (ESI) and Atmospheric pressure photoionization (APPI). The full description of samples, methods and data is given in the following sections.
To evaluate the isotopic record of climate change and carbon sequestration in the Late Paleozoic, we have compiled new and published oxygen and carbon isotopic measurements of more than 2000 brachiopod shells from Carboniferous through Middle Permian (359-260 Ma) strata worldwide. We focus on the isotopic records from the U.S. Midcontinent and the Russian Platform because these two regions provide well-preserved marine fossils spanning a broad time interval.
Brachiopod shells were processed and screened for diagenesis by different methods depending on the research group. Some groups crush shells and pick clear crystals under the microscope. Five to ten milligrams of Ca carbonate are analyzed for trace and minor elements (Mg, Sr, Fe, Mn). Other research groups thin-section shells and use cathodoluminscence and plane light microscopy to screen for diagenesis. Nonluminescent shell is microsampled (0.05-0.1 mg) on the thin-section or complementary billet. All research groups use isotope ratio mass spectrometer for carbon (13C/12C) and oxygen (18O/16O) analyses. These data are used to examine paleotemperatures and their relation to climate in the past.