Description: Acarininid shells were cast in epoxy, ground to midsection and imaged by SEM to identify suitable domains for analysis. Fully quantitative Mg/Ca analyses by a CAMECA SX-51 Electron Probe Microanalyzer (mineral standards, background subtracted, and matrix corrected) were performed using Probe for EPMA© software. An accelerating voltage of 15 kV with 10 nA Faraday current and a tightly focused beam were used, with a counting time of 20s on the peak and 10s on each of the two background positions. These analyses were performed using the “Time Dependent Intensity” feature of the Probe for EPMA software, where Ca and Mg were measured in 4 s increments and counts were plotted against time, with extrapolation to time = 0s as the true count rate. The natural carbonate standards Delight Dolomite, Callender Calcite, and UWC-3 were used for Mg and Ca; Mg-KαX-rays were measured on two spectrometers and aggregated. Carbon was calculated within the matrix correction on an atomic basis as C = (Ca + Mg + Sr). Whenever possible, multiple Mg/Ca measurements were placed in each acarininid shell, and the average value was calculated. Data Quality Information: Only EPMA analytical totals of 98.5 – 100.5 wt.% were considered acceptable

Description: Sampling and Analyzing Method: Acarininid shells were cast in epoxy, ground to midsection and imaged by SEM to identify suitable, well-preserved domains for analysis. In situ d18O data were acquired in the WiscSIMS Laboratory at the Department of Geoscience, UW-Madison, using a CAMECA IMS-1280 large radius multicollector SIMS. (Kita et al., 2009; Valley and Kita, 2009). Depending on the size of the target, samples were analyzed with a 10 µm or 3 µm primary beam. Four consecutive measurements of UWC-3 calcite standard (d18O = 12.40 per mille Vienna standard mean ocean water; VSMOW; Kozdon et al., 2009) were performed before and after every set of typically 10 sample analyses.

Description: Pelagic ecosystem function is integral to global biogeochemical cycling, and plays a major role in modulating atmospheric CO2 concentrations (pCO2). Uncertainty as to the effects of human activities on marine ecosystem function hinders projection of future atmospheric pCO2. To this end, events in the geological past can provide informative case studies in the response of ecosystem function to environmental and ecological changes. Around the Cretaceous-Palaeogene (K-Pg) boundary, two such events occurred: Deccan large igneous province (LIP) eruptions and massive bolide impact at the Yucatan Peninsula. Both perturbed the environment, but only the impact coincided with marine mass extinction. As such, we use these events to directly contrast the response of marine biogeochemical cycling to environmental perturbation with and without changes in global species richness. We measure this biogeochemical response using records of deep-sea carbonate preservation. We find that Late Cretaceous Deccan volcanism prompted transient deep-sea carbonate dissolution of a larger magnitude and timescale than predicted by geochemical models. Even so, the effect of volcanism on carbonate preservation was slight compared with bolide impact. Empirical records and geochemical models support a pronounced increase in carbonate saturation state for more than 500 000 years following the mass extinction of pelagic carbonate producers at the K-Pg boundary. These examples highlight the importance of pelagic ecosystems in moderating climate and ocean chemistry.

Description: Data from Ocean Drilling Program Site 1263 on Walvis Ridge in SE Atlantic include barite accumulation rates, benthic foraminiferal data, and carbon and oxygen isotopes for Eocene hyperthermals: PETM, ETM2, ETM3. Changes in primary productivity, in export of organic carbon from the surface ocean, and in remineralization deeper in the water column in the so-called “twilight zone” may substantially alter the marine biological carbon pump, thus carbon storage in the oceans. We present different proxy records commonly used for reconstructing paleoproductivity, and re-evaluate their use for understanding dynamic change within and between different constituents of the marine biological pump during transient global warming episodes in the past. Marine pelagic barite records are a proxy for carbon export from the photic and/or mesopelagic zone, and are not positively correlated with benthic foraminiferal proxies for arrival of organic matter to the seafloor over three early Eocene periods of global warming (Ocean Drilling Program Site 1263, SE Atlantic). These two proxies reflect processes in different parts of the water column, thus different components of the biological pump.

Description: The middle Miocene climate transition (MMCT) is characterized by an abrupt 1‰ increase in benthic foraminiferal oxygen isotopes at ca. 13.8 Ma, marking expansion of the Antarctic Ice Sheet and transition of Earth's climate to a cooler, relatively stable glacial state. Also occurring during this period is a globally recognized positive carbon isotope excursion (16.9-13.5 Ma) in benthic and planktonic foraminifera with shorter carbon isotope maxima (CM) events, linking hypotheses for climate change at the time with the carbon cycle. In order to test whether export production in the eastern equatorial Pacific is related to the largest such event (CM6), coincident with Antarctic Ice Sheet expansion, a high-resolution (〈5 k.y.) record of export production at Integrated Ocean Drilling Program Site U1337 spanning the MMCT (14.02-13.43 Ma) was produced using marine pelagic barite mass accumulation rates. Export production is elevated with an extended period of more than double present-day values. These variations are not orbitally paced and provide evidence for a reorganization of nutrients supplied to the eastern equatorial Pacific in the Miocene and intensification of upwelling. If such changes are representative of the entire region, then this mechanism could sequester enough carbon to have a significant effect on atmospheric pCO2. However, continual delivery of nutrients to the surface waters of the eastern equatorial Pacific is required in order to sustain export production without depleting the surface ocean of limiting nutrients. This might be accomplished by a change in ocean circulation or a combination of other processes requiring further study.

Description: This dataset contains measurements of δ11B, δ13C and δ18O, as well as the elemental ratios Magnesium/Calcium, Aluminium/Calcium, Strontium/Calcium from planktic foraminifera from six different ODP sites.