ALBERT

Description: This dataset contains single-shell stable isotope data (d18O and d13C), shell weights, ages, and preservation states of Cibicidoides shells spanning MIS 1-2 from ODP Site 929, Ceara Rise (5.976°N, -43.740°E, 4357 m water depth). Sediment samples were processed following standard procedures. From each 〉63µm sediment sample, all specimens of the genera Cibicidoides and Uvigerina were picked from the 〉150 µm size fraction. Using a binocular microscope, each individual Cibicidoides and Uvigerina specimen was critically evaluated for preservation quality. Details of the Foraminiferal Preservation Index (FPI) can be found in the corresponding publication. In short, an initial score (IS) of 5 is applied to an ideal specimen with clearly defined whorls, sutures, pores, and other surface features. A shell with an IS score of 3 usually contains enlarged pores and "smoothed" looking surface features, including sutures and surface ornamentation. An IS score of 4 is assigned to specimens with more subtly smoothed features, and/or slightly enlarged pores. From the IS3-5 value for a given specimen, deductions of 1-2 points are applied to generate its final score (FS). A deduction of 1 point is applied for either a missing or fractured chamber, and/or evidence of slight dissolution. A deduction of 2 points is applied for extensive missing or fractured chambers, and/or evidence of extensive dissolution. For example, an assigned FS1 value for a specimen could be the result of highly smoothed surface features, with some combination of extensive dissolution pockmarks and/or one to several fractured/missing chambers (i.e. IS3 - 2 = FS1). The letter "A" assigned to the final score indicates that the appearance of the shell is glassy, "B" is assigned to pseudo-glassy shells, and "C" to frosty specimens. Specimens of varying preservation quality were purposely chosen for single-shell stable isotope analyses. Each specimen was weighed, and shells featuring narrow mass ranges were selected for individual analytical runs of d18O and d13C which allows for the optimization of instrument tuning. Single Cibicidoides shells were analyzed on a Thermo Delta V Kiel IV dual inlet mass spectrometer at the Lamont-Doherty Earth Observatory, and were corrected relative to the NBS-19 calcite standard. Average precision on these analyses was better than 0.08‰ for δ18O and better than 0.06‰ for δ13C. The age model is based on published stable isotope records (Bickert et al., 1997; Billups et al., 1998) tuned to the deep sea benthic d18O stack (Lisiecki and Raymo, 2005; Ahn et al., 2017).

Description: The oxygen isotopic composition of benthic foraminifera (d18Ob) is widely used to date and correlate marine sediment sequences. However, d18Ob has found comparatively little use in the Arctic Ocean due both to uncertainty in Arctic marine sediment chronology and the lack of resemblance between Arctic and open ocean d18Ob records. We address this issue by combining Arctic d18Ob records (Cronin et al., 2019) with benthic ostracode Mg/Ca-BWT reconstructions (Cronin et al., 2017) to create a composite record of the history of seawater d18O in the intermediate-to-deep Arctic Ocean over the last 600 kyr. Seawater d18O and its uncertainty was calculated using PSU Solver (Thirumalai et al., 2016).

Description: This dataset contains single-shell stable isotope data (d18O and d13C), shell weights, ages, and preservation states of Cibicidoides shells spanning MIS 9-10 from ODP Site 1089 north of Agulhas Ridge (-40.936°N, 9.894°E, 4620 m water depth). Sediment samples were processed following standard procedures. From each 〉63µm sediment sample, all specimens of the genera Cibicidoides and Uvigerina were picked from the 〉150 µm size fraction. Using a binocular microscope, each individual Cibicidoides and Uvigerina specimen was critically evaluated for preservation quality. Details of the Foraminiferal Preservation Index (FPI) can be found in the corresponding publication. In short, an initial score (IS) of 5 is applied to an ideal specimen with clearly defined whorls, sutures, pores, and other surface features. A shell with an IS score of 3 usually contains enlarged pores and “smoothed” looking surface features, including sutures and surface ornamentation. An IS score of 4 is assigned to specimens with more subtly smoothed features, and/or slightly enlarged pores. From the IS3-5 value for a given specimen, deductions of 1-2 points are applied to generate its final score (FS). A deduction of 1 point is applied for either a missing or fractured chamber, and/or evidence of slight dissolution. A deduction of 2 points is applied for extensive missing or fractured chambers, and/or evidence of extensive dissolution. For example, an assigned FS1 value for a specimen could be the result of highly smoothed surface features, with some combination of extensive dissolution pockmarks and/or one to several fractured/missing chambers (i.e. IS3 – 2 = FS1). The letter “A” assigned to the final score indicates that the appearance of the shell is glassy, “B” is assigned to pseudo-glassy shells, and “C” to frosty specimens. Specimens of varying preservation quality were purposely chosen for single-shell stable isotope analyses. Each specimen was weighed, and shells featuring narrow mass ranges were selected for individual analytical runs of d18O and d13C which allows for the optimization of instrument tuning. Single Cibicidoides shells were analyzed on a Thermo Delta V Kiel IV dual inlet mass spectrometer at the Lamont-Doherty Earth Observatory, and were corrected relative to the NBS-19 calcite standard. Average precision on these analyses was better than 0.08‰ for δ18O and better than 0.06‰ for δ13C. The age model is based on the published stable isotope record (Hodell et al. 2001) tuned to the deep sea benthic d18O stack (Lisiecki and Raymo, 2005; Ahn et al., 2017).

Description: This dataset contains single-shell stable isotope data (d18O and d13C), shell weights, ages, and preservation states of Cibicidoides shells spanning MIS 1-2 from ODP Site 846 south of the Galapagos Islands (-3.095°N, -90.818°E, 3296 m water depth). Sediment samples were processed following standard procedures. From each 〉63µm sediment sample, all specimens of the genera Cibicidoides and Uvigerina were picked from the 〉150 µm size fraction. Using a binocular microscope, each individual Cibicidoides and Uvigerina specimen was critically evaluated for preservation quality. Details of the Foraminiferal Preservation Index (FPI) can be found in the corresponding publication. In short, an initial score (IS) of 5 is applied to an ideal specimen with clearly defined whorls, sutures, pores, and other surface features. A shell with an IS score of 3 usually contains enlarged pores and “smoothed” looking surface features, including sutures and surface ornamentation. An IS score of 4 is assigned to specimens with more subtly smoothed features, and/or slightly enlarged pores. From the IS3-5 value for a given specimen, deductions of 1-2 points are applied to generate its final score (FS). A deduction of 1 point is applied for either a missing or fractured chamber, and/or evidence of slight dissolution. A deduction of 2 points is applied for extensive missing or fractured chambers, and/or evidence of extensive dissolution. For example, an assigned FS1 value for a specimen could be the result of highly smoothed surface features, with some combination of extensive dissolution pockmarks and/or one to several fractured/missing chambers (i.e. IS3 – 2 = FS1). The letter “A” assigned to the final score indicates that the appearance of the shell is glassy, “B” is assigned to pseudo-glassy shells, and “C” to frosty specimens. Specimens of varying preservation quality were purposely chosen for single-shell stable isotope analyses. Each specimen was weighed, and shells featuring narrow mass ranges were selected for individual analytical runs of d18O and d13C which allows for the optimization of instrument tuning. Single Cibicidoides shells were analyzed on a Thermo Delta V Kiel IV dual inlet mass spectrometer at the Lamont-Doherty Earth Observatory, and were corrected relative to the NBS-19 calcite standard. Average precision on these analyses was better than 0.08‰ for δ18O and better than 0.06‰ for δ13C. The age model is based on published stable isotope records (Mix et al. 1995; Shackleton et al., 1995) tuned to the deep sea benthic d18O stack (Lisiecki and Raymo, 2005; Ahn et al., 2017).

Description: This dataset contains single-shell stable isotope data (d18O and d13C), shell weights, ages, and preservation states of Uvigerina shells spanning MIS 9-10 from ODP Site 846 south of the Galapagos Islands (-3.095°N, -90.818°E, 3296 m water depth). Sediment samples were processed following standard procedures. From each 〉63µm sediment sample, all specimens of the genera Cibicidoides and Uvigerina were picked from the 〉150 µm size fraction. Using a binocular microscope, each individual Cibicidoides and Uvigerina specimen was critically evaluated for preservation quality. Details of the Foraminiferal Preservation Index (FPI) can be found in the corresponding publication. In short, an initial score (IS) of 5 is applied to an ideal specimen with clearly defined whorls, sutures, pores, and other surface features. A shell with an IS score of 3 usually contains enlarged pores and "smoothed" looking surface features, including sutures and surface ornamentation. An IS score of 4 is assigned to specimens with more subtly smoothed features, and/or slightly enlarged pores. From the IS3-5 value for a given specimen, deductions of 1-2 points are applied to generate its final score (FS). A deduction of 1 point is applied for either a missing or fractured chamber, and/or evidence of slight dissolution. A deduction of 2 points is applied for extensive missing or fractured chambers, and/or evidence of extensive dissolution. For example, an assigned FS1 value for a specimen could be the result of highly smoothed surface features, with some combination of extensive dissolution pockmarks and/or one to several fractured/missing chambers (i.e. IS3 - 2 = FS1). The letter "A" assigned to the final score indicates that the appearance of the shell is glassy, "B" is assigned to pseudo-glassy shells, and "C" to frosty specimens. Specimens of varying preservation quality were purposely chosen for single-shell stable isotope analyses. Each specimen was weighed, and shells featuring narrow mass ranges were selected for individual analytical runs of d18O and d13C which allows for the optimization of instrument tuning. Single Uvigerina shells were analyzed on an Isoprime 100 dual inlet mass spectrometer with carbonate multi-preparation system at Rensselaer Polytechnic Institute, and were corrected relative to the NBS-19 calcite standard. These analyses produced average precision better than 0.06‰ for δ18O and better than 0.03‰ for δ13C. The age model is based on published stable isotope records (Mix et al. 1995; Shackleton et al., 1995) tuned to the deep sea benthic d18O stack (Lisiecki and Raymo, 2005; Ahn et al., 2017).

Description: This dataset contains single-shell stable isotope data (d18O and d13C), shell weights, ages, and preservation states of Cibicidoides shells spanning MIS 9-10 from ODP Site 846 south of the Galapagos Islands (-3.095°N, -90.818°E, 3296 m water depth). Sediment samples were processed following standard procedures. From each 〉63µm sediment sample, all specimens of the genera Cibicidoides and Uvigerina were picked from the 〉150 µm size fraction. Using a binocular microscope, each individual Cibicidoides and Uvigerina specimen was critically evaluated for preservation quality. Details of the Foraminiferal Preservation Index (FPI) can be found in the corresponding publication. In short, an initial score (IS) of 5 is applied to an ideal specimen with clearly defined whorls, sutures, pores, and other surface features. A shell with an IS score of 3 usually contains enlarged pores and “smoothed” looking surface features, including sutures and surface ornamentation. An IS score of 4 is assigned to specimens with more subtly smoothed features, and/or slightly enlarged pores. From the IS3-5 value for a given specimen, deductions of 1-2 points are applied to generate its final score (FS). A deduction of 1 point is applied for either a missing or fractured chamber, and/or evidence of slight dissolution. A deduction of 2 points is applied for extensive missing or fractured chambers, and/or evidence of extensive dissolution. For example, an assigned FS1 value for a specimen could be the result of highly smoothed surface features, with some combination of extensive dissolution pockmarks and/or one to several fractured/missing chambers (i.e. IS3 – 2 = FS1). The letter “A” assigned to the final score indicates that the appearance of the shell is glassy, “B” is assigned to pseudo-glassy shells, and “C” to frosty specimens. Specimens of varying preservation quality were purposely chosen for single-shell stable isotope analyses. Each specimen was weighed, and shells featuring narrow mass ranges were selected for individual analytical runs of d18O and d13C which allows for the optimization of instrument tuning. Single Cibicidoides shells were analyzed on an Isoprime 100 dual inlet mass spectrometer with carbonate multi-preparation system at Rensselaer Polytechnic Institute, and were corrected relative to the NBS-19 calcite standard. These analyses produced average precision better than 0.06‰ for δ18O and better than 0.03‰ for δ13C. The age model is based on published stable isotope records (Mix et al. 1995; Shackleton et al., 1995) tuned to the deep sea benthic d18O stack (Lisiecki and Raymo, 2005; Ahn et al., 2017).

Description: Marine diatoms are silica-precipitating microalgae that account for over half of organic carbon burial in marine sediments and thus they play a key role in the global carbon cycle. Their evolutionary expansion during the Cenozoic era (66 Ma to present) has been associated with a superior competitive ability for silicic acid relative to other siliceous plankton such as radiolarians, which evolved by reducing the weight of their silica test. Here we use a mathematical model in which diatoms and radiolarians compete for silicic acid to show that the observed reduction in the weight of radiolarian tests is insufficient to explain the rise of diatoms. Using the lithium isotope record of seawater as a proxy of silicate rock weathering and erosion, we calculate changes in the input flux of silicic acid to the oceans. Our results indicate that the long-term massive erosion of continental silicates was critical to the subsequent success of diatoms in marine ecosystems over the last 40 My and suggest an increase in the strength and efficiency of the oceanic biological pump over this period.

Description: A major unresolved aspect of the rise of dinosaurs is why early dinosaurs and their relatives were rare and species-poor at low paleolatitudes throughout the Late Triassic Period, a pattern persisting 30 million years after their origin and 10–15 million years after they became abundant and speciose at higher latitudes. New palynological, wildfire, organic carbon isotope, and atmospheric pCO2 data from early dinosaur-bearing strata of low paleolatitudes in western North America show that large, high-frequency, tightly correlated variations in δ13Corg and palynomorph ecotypes occurred within a context of elevated and increasing pCO2 and pervasive wildfires. Whereas pseudosuchian archosaur-dominated communities were able to persist in these same regions under rapidly fluctuating extreme climatic conditions until the end-Triassic, large-bodied, fast-growing tachymetabolic dinosaurian herbivores requiring greater resources were unable to adapt to unstable high CO2 environmental conditions of the Late Triassic.