MATERIAL AND METHODS

Approximately 2400 20-cm³ samples were taken from the composite sections at Sites 1094 and 1091 at 5-cm intervals and at Site 1093 at 10-cm intervals. Prior to sample preparation, we removed 1 cm³ from each sample to provide material for subsequent weight percent CaCO₃ measurements. The samples were then dried at 70°C for 24 hr to obtain the dry bulk weight per sample. After weighing, each sample was soaked in distilled water and left for 12 hr on a shaking table to desegregate. The samples were then cleaned carefully with a brush and wet sieved into three fractions (>63, >150, and >500 µm) and the <63-µm fraction was collected in a 2-L beaker to settle for up to 7 days. Following this, each coarse fraction was dried, weighed, and transferred to a sample glass. The fine fractions (<63 µm) were dried, transferred into Ziplock bags, and shipped to Weslayan University for subsequent analyses by ODP Leg 177 shipboard scientist S. O'Conell.

Stable isotope analyses were conducted at the Department of Geology at the University of Bergen. The planktonic foraminiferal isotopic analyses were performed on 12 to 14 individual tests of Neogloboquadrina pachyderma (sinistral), selected from the >150- to 250-µm size fraction. Prior to analyses, all foraminiferal shells were soaked in 15% H₂O₂ for 15 min to remove organic matter and the H₂O₂ was removed using a syringe. Following this, all shells were cracked open to release potential sediment fillings and ultrasonically rinsed for 1 min in methanol to remove the fine-grained particles. The methanol was removed using a syringe, and the samples were allowed to evaporate to dryness in a drying cabinet. The foraminifer shells were then loaded into individual reaction glasses, and each sample was reacted with three drops of H₃PO₄ using a MAT Carbo Kiel III automated preparation line. Isotope ratios were measured on a Finnigan MAT 252 mass spectrometer. The data are reported as ¹⁸O vs. the Vee Pee Dee belemnite (VPDB) standard after calibration with NBS-19 standard (Coplen, 1995). Analytical precision of the system as defined by replicate measurements of carbonate standards is ±0.06 for ¹³C and ±0.07 for ¹⁸O.