Global warming during the Palaeocene-Eocene Thermal Maximum (PETM, ~56 Ma) is commonly interpreted as being driven by massive destabilization of carbon from surficial sedimentary reservoirs. If correct, this has important implications for the amplification of future fossil fuel emissions via carbon-climate feedbacks. In our study we provided new paired records of boron and carbon isotope changes in the ocean that questions this long-held interpretation. Our data are implemented in an Earth system model to reconstruct the unfolding carbon cycle dynamics across the event. Strong evidence for a larger (>10,000 PgC) and on average isotopically heavier (> -17‰) carbon source leads us to identify volcanism associated with the North Atlantic Igneous Province as the main driver of the PETM. We also find that although organic carbon feedbacks with climate played a more minor role in driving the event than previously thought, organic matter burial was important in ultimately sequestering this carbon and driving the recovery of the system. Data presented in this data set comprise geochemical elemental, as well as boron, carbon and oxygen isotopic data from surface dwelling foraminifera Morozovella Subbotina. Alongside the boron isotopic data we also provide reconstructed surface water pH with corresponding uncertainties for our preferred pH reconstruction.
Geochemical and isotopic data presented here cover the Paleocene-Eocene Thermal Maximum (~56 Ma ago) and were produced to assess the degree of carbon cycle perturbations, ocean acidification and the origin of the emitted carbon added to the atmosphere-ocean system during this major carbon cycle perturbation event. For further details on the analytical approach please refer to the original publication (Gutjahr et al., 2017, Nature). Data contained within the two tables comprise foraminiferal carbonate based stable boron, carbon and oxygen isotopic results from DSDP Site 401 located within the Bay of Biscaye in the NE Atlantic (Table 1). This table also contains B/Ca, Mg/Ca and Al/Ca data from the same samples. Depth in core is presented alongside two alternative relative age models setting ages in relation to the Carbon Isotope Excursion observed during the Paleocene Eocene Thermal Maximum. Table 2 contains high-resolution bulk carbonate stable carbon and oxygen isotopic results that were produced to establish a new age models for this core.
The RAGNARoCC dataset includes surface and deep ocean measurements of greenhouse gas concentrations including carbon dioxide, methane and nitrous oxide. The dataset was collected in the North Atlantic Ocean during the RRS James Clark Ross cruise JR20140531 (JR302) which surveyed from Canada, to Greenland, to the United Kingdom via Iceland. The JR302 cruise started on 6th June 2014 and finished on 22nd July 2014. Some water samples were analysed aboard ship, whilst others were subsequently analysed ashore. The dataset is based on data and water samples collected by surface underway measurements and during CTD stations from the RRS James Clark Ross. The RAGNARoCC dataset was collected to understand the size and variability of the sources and sinks of greenhouse gases between the ocean and atmosphere in the North Atlantic Ocean. The dataset was produced by various members of the RAGNARoCC project consortium. Dr. Brian King was the cruise principal investigator for JR302. The data are made available by the British Oceanographic Data Centre, with relevant data also contributing to community research portals such as http://www.socat.info/. The dataset currently includes some of the data from cruise JR302, but is expected to include additional data from JR302. Additional data is also expected from the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) mooring; the Voluntary Observing Ship (VOS) MV Benguela Stream; data from a Bay of Biscay Ferry-box route; and the RRS Discovery cruise DY040.