) notation relative to the Vienna Peedee belemnite (VPDB) standard. Analytical precision for 
13C and 18O values is 0.05 and 0.08, respectively, and was monitored through multiple analyses of NBS-19 standard.
Core samples from Holes 1170A and 1172A were obtained aboard the JOIDES Resolution during Leg 189 (Exon, Kennett, Malone, et al., 2001). Each sample consists of two 10-cm3 tubes that occupy a downcore interval of ~4 cm. Miocene sections at the two sites are entirely composed of nannofossil ooze and chalk (Site 1170 bulk carbonate content = >90 wt% and Site 1172 = >85 wt%) that contains moderately to well-preserved planktonic and benthic foraminiferal tests (except for the condensed intervals of the lower Miocene, in which planktonic foraminiferal tests are moderately infilled).
Sediment samples were disaggregated with distilled–deionized (DDI) water and wet sieved through a 63-µm screen. The <63-µm fraction was oven-dried at ~60°C and processed for stable isotope analyses. Separated coarse-fraction (>63 µm) samples were soaked in a 3% hydrogen peroxide solution for a day, rinsed and heated in hot (~90ºC) DDI water, ultrasonicated, and repeatedly rinsed in DDI water until adhering material on the surface of foraminiferal tests was removed. The coarse-fraction samples were then sieved into 250-, 354-, and 420-µm fractions, and well-preserved foraminiferal specimens from the 250- to 354-µm and 354- to 420-µm fractions were hand picked. For each sample, multiple foraminifer specimens (i.e., typically 5–10 specimens for benthic foraminifers and 10–15 specimens for planktonic foraminifers) of the same species were separated, crushed between two glass slides, brush-cleaned in methanol to remove remaining adhering particles from inner shell walls, when present, and processed for stable isotope analyses.
Separated foraminifers and bulk fine-fraction (<63 µm) samples were reacted with 100% anhydrous phosphoric acid at 90ºC in an automated common acid bath carbonate device coupled to a Finnigan MAT 252 mass spectrometer for carbon and oxygen stable isotope analyses in the Penn State Stable Isotope Biogeochemistry Laboratory. Stable isotopic values are reported in per mil () notation relative to the Vienna Peedee belemnite (VPDB) standard. Analytical precision for 13C and 18O values is 0.05 and 0.08, respectively, and was monitored through multiple analyses of NBS-19 standard.
