*3.4. Geochemical Analysis*

*δ* Ο *δ* Ο *δ* Ο δ δ In order to reconstruct the oceanographic regime of the time interval surrounding the increased shell mass event during T-II, 12 adjacent down core samples, covering the period of ~22,000 years between 119 and 140 ka, were geochemically analysed to determine shell Mg/Ca ratios for seawater temperature estimations and δ <sup>18</sup>O isotope (δ <sup>18</sup>Oshell). Mg-derived temperatures and foraminiferal

*δ δ*

*δ*

*δ* Ο

δ <sup>18</sup>Oshell were used together to assess changes in seawater δ <sup>18</sup>O (δ <sup>18</sup>Osw) composition. Mg/Ca ratios were converted to temperatures using an equation for temperate ranges [33]. δ <sup>18</sup>Osw was calculated using a published paleotemperature equation [34], and a VPDB-to-SMOW δ <sup>18</sup>O conversion of 0.27‰ [35]. Salinity estimates were derived from δ <sup>18</sup>Osw using the tropical Atlantic salinity-δ <sup>18</sup>Osw relationship [36] and corrected for deglacial whole ocean salinity changes using a 120 m scaled sea-level curve [37] and an average ocean depth of 3800 m. Seawater densities were calculated from temperature and salinity estimates using the equation state of the water [38] at a (*G. bulloides* calcification) depth of 100 m. In order to test the correlation between shell mass and the different environmental and oceanographic data, two-tailed regression analyses were performed using the reduced major axis model, at *n* − 1 degrees of freedom (*n* representing sample size).
