High-resolution proxy records are needed to evaluate models simulating past, present and future climatic conditions. Before such records can be reliably employed, calibration studies have to be conducted to assess the confidence intervals of the proxies. Here, we use shells of the fast growing Pacific oyster Magallana gigas from the Central Wadden Sea, North Sea, a temperate barrier island-backbarrier tidal flat-salt marsh system with large seasonal changes of water mass-properties, for the calibration of geochemical proxies. M. gigas represents a nonnative invasive species that rapidly develops oyster reefs. Calcite shells of two specimens from the intertidal and subtidal zones were sampled in high resolution yielding sub-monthly data sets. The time period represented in the shell, based on δ18O age modeling, was estimated at 8–10 years and the growth of the shells was restricted from (late) spring to (early) autumn of each year. Mg/Ca, Mn/Ca and Sr/Ca ratios of the intertidal and subtidal specimens show similar seasonal patterns. Mg/Ca and Sr/Ca ratios are investigated as high-resolution sea surface temperature (SST) proxies. Important ontogenetic effects (i.e., increasing time-averaging with increasing age) as well as inter-specimen variability are discussed as limiting factors for the proxy development. Intertidal Mg/Ca ratios show only a significant correlation to the high-resolution SST record of the Central Wadden Sea when the early ontogenetic stage is considered. Sr/Ca ratios were comparable in terms of absolute values and amplitudes to those of M. gigas in the Northern Wadden Sea, but amplitudes were decreasing with increasing age. These findings seriously hamper the application of Mg/Ca and Sr/Ca for reliable palaeotemperature reconstructions regardless of ontogenetic stage. The Mn/Ca ratios were investigated as proxy for Mn cycling in tidal basins, where it is interrelated with seasonal changes in primary production. In addition to the generally observed seasonal variability of the Mn/Ca oyster records, the subtidal Mn/Ca is significantly elevated compared to intertidal Mn/Ca. The subtidal Mn/Ca offset likely reflects differences in Mn cycling in tidal settings and could, therefore, serve in the palaeorecord as indicator to differentiate inter- and subtidal habitats in the same embedding sedimentary facies. This habitat effect has to be considered as an important factor besides environmental change when interpreting the high-resolution proxy record of fossil oysters.
The dataset reports sediment data obtained from a three-year sediment trapping (2011-2013 CE) at two locations (proximal and distal towards the river inflow) in Lake Mondsee, Austria in comparison to a varved surface sediment core (1986-2013 CE) from the distal location and river runoff. The sediment trap data includes stable oxygen and carbon isotope composition, sediment flux and carbon contents, the sediment core data includses stable oxygen and carbon isotope composition of seasonal calcite layers and bulk samples and the thickness of detrital layers.
Here we compiled stable carbon isotope data from 23 ODP sites in the Atlantic and Pacific, binned by marine isotope stage.Stable carbon isotope data were binned and averaged according to the marine isotope age assignments in the LR04 and the reported ages of the samples from each site. Only Cibicidoides wuellerstorfi values were used, although sometimes measured species was not reported for each sample by the original publication. Please note that some sites have data originating from multiple publications.
Calculated values for whole basin δ13C of dissolved inorganic carbon, calculated Δδ13C, and associated uncertainties from the values compiled in MPWP_benthic_isotope_data_compilation. Benthic δ13C data from all sites below 2000 meters water depth were binned by marine isotope stage as defined by the age bounds provided with the LR04 stack. Because of our focus on specific MIS events, sedimentary records with low-resolution age models were excluded. All data are derived from Cibicidoides wuellerstorfi. In datasets composed of isotope measurements of two or more benthic foraminifera species (e.g., ODP 883), only C. wuellerstorfi δ13C data were used. The mean of the binned data across the entire isotope stage from each site was then used to calculate a mean deep Pacific and mean deep Atlantic δ13CDIC estimate for all 11 marine isotope stages in the MPWP, assuming a 1:1 relationship between C. wuellerstorfi δ13C and δ13CDIC. All sites were weighed equally.