(Table S1) Boron isotope and trace element data and reconstructed carbonate system parameters, ODP Holes 122-761B and 154-926A ...

• Main Authors: Foster, Gavin L, Lear, Caroline H, Rae, James W B
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: Event label; Sample code/label; DEPTH, sediment/rock; AGE; Species; Globigerinoides sacculifer, Magnesium/Calcium ratio; Cibicidoides wuellerstorfi, Magnesium/Calcium ratio; Cibicidoides mundulus, Magnesium/Calcium ratio; δ11B; Standard error; Boron; δ11B, standard deviation; Temperature, calculated; pH; Error; Carbonate ion; Carbonate ion, standard deviation; Carbon dioxide, partial pressure; Carbon dioxide, partial pressure, standard deviation; Drilling/drill rig; DSDP/ODP/IODP sample designation; ICP-MS, Thermo Fisher Scientific, Element 2; MC-ICP-MS, Thermo Fisher Scientific NEPTUN; Calculated; Leg122; Leg154; Joides Resolution; Ocean Drilling Program ODP; Antarctic; Neptun; The Antarctic; Antarc*; Ice Sheet
• Online Access: https://dx.doi.org/10.1594/pangaea.815855; https://doi.pangaea.de/10.1594/PANGAEA.815855

The middle Miocene Climatic Optimum (17-15 Ma; MCO) is a period of global warmth and relatively high CO2 and is thought to be associated with a significant retreat of the Antarctic Ice Sheet (AIS). We present here a new planktic foraminiferal d11B record from 16.6 to 11.8 Ma from two deep ocean sites currently in equilibrium with the atmosphere with respect to CO2. These new data demonstrate that the evolution of global climate during the middle Miocene (as reflected by changes in the cyrosphere) was well correlated to variations in the concentration of atmospheric CO2. What is more, within our sampling resolution (~1 sample per 300 kyr) there is no evidence of hysteresis in the response of ice volume to CO2 forcing during the middle Miocene, contrary to what is understood about the Antarctic Ice Sheet from ice sheet modelling studies. In agreement with previous data, we show that absolute levels of CO2 during the MCO were relatively modest (350-400 ppm) and levels either side of the MCO are similar or lower ... : Sediment depth is given in mcd. Carbonate system parameters calculated using d11B(seawater) = 37.82 per mil and ALK(surface) = 1292 mmol/kg and ALK(deep) = 1392 mmol/kg. All carbonate system calculations were carried out accounting for the effect of changing [Ca] and [Mg] on K1, K2 and Ksp. ...