Maastrichtian composite bulk carbonate stable isotopes, XRF scanning, biogenic barium, and benthic foraminiferal records from Shatsky Rise, ODP Sites 1209 and 1210

A bulk composite carbonate stable isotope, X-ray fluorescence (XRF) scanning (elemental barium), biogenic barium and benthic foraminiferal record in deep sea sediments from the tropical Pacific was produced from 71.5 to 66 million years ago to determine variations in carbon export in the Pacific during the Maastrichtian. The cores were drilled on Shatsky Rise in the tropical Pacific at Ocean Drilling Program (ODP) Leg 198 Sites 1209 and 1210 whose current locations are 32°39.1081′N, 158°30.3564′E (2387 m below sea level) and 32°13.420′N, 158°15.5623′E (2573 m below sea level), respectively (Bralower et al., 2002). Bulk carbonate δ18O and δ13C were measured in 1394 samples from both Sites 1209 (1096) and 1210 (298) about every 5 cm at MARUM, University Bremen. Bulk carbonate analyses were carried out on a Finnigan MAT 251 mass spectrometer equipped with automated carbonate preparation line (Kiel III) and reported relative to the Vienna Pee Dee Belemnite (VPDB) international standard, determined via adjustment to calibrated in-house standards and NBS-19. Non-destructive XRF data were collected every 2 cm down-core using XRF core scanner Avaatech serial no. 17 from the XRF core scanning facility at the IODP Gulf Coast Repository at Texas A&M University (College Station, USA). Data were collected over a 1.2 cm² area with a down-core slit size of 10 mm using generator settings of 50 kV and a current of 0.75 mA, ideally for detecting Ba, and a sampling time of 12 s in each run directly at the split core surface of the archive half. Discrete samples from 5 intervals that consist of 51 samples in total were processed to determine the marine barite content using a barite separation process modified from Paytan et al. (1996) and excess-Ba (bio-Ba) by measuring the digested bulk sample on a Perkin Elmer 3000DV ICP-OES and using equation from Dymond et al. (1992). Additional samples for benthic foraminifera were taken from over 2 of the 5 intervals that have barite data. Benthic foraminiferal quantitative analysis was carried out at University of Zaragoza based on representative splits of approximately 300 specimens larger than 63 µm.